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Two ruthenium(II) polypyridyl complexes were prepared with the {Ru(phen)2}2+ moiety and a third sterically non-hindering bidentate ligand, namely 2,2′-dipyridylamine (dpa) and N-benzyl-2,2′-dipyridylamine (Bndpa). Hence, complexes [Ru(phen)2(dpa)](PF6)2 (1) and [Ru(phen)2(Bndpa)](PF6)2 (2) were characterized and their photochemical behaviour in solution (acetonitrile and water) was subsequently investigated. Compounds 1 and 2, which do not exhibit notably distorted octahedral coordination environments, contrarily to the homoleptic “parent” compound [Ru(phen)3](PF6)2, experience two-step photoejection of the dpa and Bndpa ligand upon irradiation (1050–430 nm) for several hours. DNA-binding studies revealed that compounds 1 and 2 affect the biomolecule differently upon irradiation; while 2 solely modifies its electrophoretic mobility, complex 1 is also capable of cleaving it. In vitro cytotoxicity studies with two cancer-cell lines, namely A549 (lung adenocarcinoma) and A375 (melanoma), showed that both 1 and 2 are not toxic in the dark, while only 1 is significantly cytotoxic if irradiated, 2 remaining non-toxic under these conditions. Graphical abstract Light irradiation of the complex cation [Ru(phen)2(dpa)]2+ leads to the generation of transient Ru species that is present in the solution medium for several hours, and that is significantly cytotoxic, ultimately producing non-toxic free dpa and [Ru(phen)(OH2)2]2+.

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2023, Tutor: Xavier Companyó Montaner, This project aims to optimise and scale-up the synthesis of a ruthenium coordination complex (dye N-179) used as photosensitiser in dye-sensitized solar cells (DSSC) and assess its implementation at industrial scale. This type of cells offers an alternative to silicon-based solar cells and has received a lot of attention due to its low cost, easy manufacturing, and relatively high conversion efficiency from solar energy to electricity. Apart from synthesizing and characterizing the dye N 719, this project aims to evaluate the production costs for its eventual implementation at industrial level. The project starts with the synthesis of 2,2’-bipyridine-4,4’-dicarboxylic acid from 2-amino-4-methylpyridine as the organic ligand and subsequently, the optimisation of its complexation and the formation of the dye N 719. I synthesize and optimize all the steps, characterising the different product intermediates, obtaining the ruthenium complex N 719 in 1.55 g scale an overall yield of the reactions of 17 %. This TFG project has been carried out in the collaboration with HDOS Innova SL., a research company that focuses its studies on environmental management problems such as the industrial development of solar cells.

We have recently reported a series of piano-stool ruthenium(II) complexes of the general formula [RuCl2(η6-arene)(P(1-pyrenyl)R2R3)] showing excellent cytotoxic activities (particularly when R2 = R3 = methyl). In the present study, new members of this family of compounds have been prepared with the objective to investigate the effect of the steric hindrance of a bulky phosphane ligand, namely diisopropyl(1-pyrenyl)phosphane (L), on exchange reactions involving the coordinated halides (X = Cl, I). Two η6-arene rings were used, i.e. η6-methyl benzoate (mba) and η6-p-cymene (p-cym), and four complexes were synthesized, namely [RuCl2(mba)(L)] (1Cl2iPr), [RuI2(mba)(L)] (1I2iPr), [RuCl2(p-cym)(L)] (2Cl2iPr), and [RuI2(p-cym)(L)] (2I2iPr). Unexpectedly, all of the complexes exhibited poor cytotoxic activities after 24 h of incubation with cells, in contrast to the related compounds previously reported. However, it was observed that aged DMSO solutions of 2I2iPr (from 2 to 7 days) exhibited better activities in comparison to freshly prepared solutions and that the activity improved over “aging” time. Thorough studies were therefore performed to uncover the origin of this lag time in the cytotoxicity efficiency. The data achieved clearly demonstrated that compounds 2I2iPr and 2Cl2iPr were undergoing a series of transformation reactions in DMSO (with higher rates for the iodido complex 2I2iPr), ultimately generating cyclometalated species through a mechanism involving DMSO as a coordinated proton abstractor. The cyclometalated complexes detected in solution were subsequently prepared; hence, pure [RuCl(p-cym)(κ2C-diisopropyl(1-pyrenyl)phosphane)] (3CliPr), [RuI(p-cym)(κ2C-diisopropyl(1-pyrenyl)phosphane)] (3IiPr), and [Ru(p-cym)(κS-dmso)(κ2C-diisopropyl(1-pyrenyl)phosphane)]PF6 (3dmsoiPr) were synthesized and fully characterized. Remarkably, 3CliPr, 3IiPr, and 3dmsoiPr are all very efficient cytotoxic agents, exhibiting slightly better activities in comparison to the chlorido noncyclometalated complexes [RuCl2(η6-arene)(P(1-pyrenyl)R2R3)] described in an earlier report. For comparison purposes, the iodido compounds [RuI2(mba)(dimethyl(1-pyrenyl)phosphane)] (1I2Me) and [RuI2(p-cym)(dimethyl(1-pyrenyl)phosphane)] (2I2Me), bearing the less hindered dimethyl(1-pyrenyl)phosphane ligand, have also been prepared. The cytotoxic and chemical behaviors of 1I2Me and 1I2Me were comparable to those of their chlorido counterparts reported previously., Financial support from the Spanish Ministerio de Ciencia Innovación, y Universidades (Project Nos. CTQ2015-65040-P, RED2018-102471-T, PID2019-107006GB-C21, PGC2018-098630-B-I00, and CTQ2017-88446-R AEI/FEDER, UE) and from the Instituto de Salud Carlos III (ISCIIIFIS PI18/00441, FEDER) is acknowledged. A.G. thanks the Royal Society of Chemistry for financial support (RSC Research Fund grant RF19-7147). J.C. thanks the Spanish MICINN for a Ramoń y Cajal research contract (RYC2018-024692-I) and the Spanish Structures of Excellence María de Maeztu program (MDM-2017-0767). P.G. acknowledges the Institució Catalana de Recerca i Estudis Avançats (ICREA).

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2022, Tutora: Amparo Caubet Marin, Derivate terpyridine ligands have been synthesized, following the combination of two reactions: the Michael addition and the Kröhnke condensation, giving rise to 4’-(4-bromophenyl)-2,2’:6’,2”-terpyridine (3a) and 4’-(4-aniline)-2,2’:6’,2”-terpyridine (3b). The reaction of 4'-chloro-2,2':6',2''-terpyridine or 3a with naphthalen-2-ylmethanol produces 4’-(naphthalen-2-ylmethoxy)-2,2’:6’,2”-terpyridine (3c) or 4’-(4-(naphthalen-2-ylmethoxy)phenyl)-2,2’:6’,2”-terpyridine (3d), respectively. These ligands react with RuCl3·3H2O to give ruthenium (III) complexes: [Ru(Brtrp)Cl3] (4a), [Ru(Anitrp)Cl3] (4b), [Ru(Ntrp)Cl3] (4c) and [Ru(BrNtrp)Cl3](4d). Their reduction and the substitution of the two chloride for bidentate N,N ligands, such as 2,2'-bipyridine, 1,10-phenanthroline or 2,2’-dipyridylamine allows to obtain [Ru(Brtrp)(bipy)Cl]Cl (5a), [Ru(Brtrp)(phen)Cl]Cl (5a’), [Ru(Brtrp)(dpa)Cl]Cl (5a”), and [Ru(Ntrp)(bipy)Cl]Cl (5c). In order to try to modify their photochemical properties, the complexes [Ru(Brtrp)(N,N)(py)](PF6)2, where N, N = bipy (6a), phen (6a’), dpa (6a”) have been obtained from (5a-a”) by substitution of the chlorine atom coordinated to the ruthenium for a pyridine group. Also the complexes with two terpyridine ligands [Ru(Brtrp)2](PF6)2 (7a) and [Ru(Brtrp)(Ntrp)](PF6)2 (7b) were synthesized. The ligands and the ruthenium (II) complexes have been characterized by infrared spectroscopy (IR), mass spectrometry, and when it has been possible, by mono- and bidimensional NMR spectroscopies. Furthermore, the determination of the absorbance of the synthesized compounds by UV-vis and their fluorescence by emission and excitation spectra were carried out. Finally, the interaction of some of the complexes with DNA has been studied by UV-Vis and electrophoresis. The results obtained from these techniques indicate that the synthesized complexes have a covalent and/or intercalation interaction with DNA and for complexes 5a and 7a a moderately strong intrinsic binding constant.

Reactions of optically pure P-stereogenic ortho-tolyl substituted phosphines with [RuCl2(p-cymene)]2 afforded the corresponding κP-coordinated ruthenium(II) dichlorides (C1′, C2’) even in the presence of sodium acetate. In contrast, the ruthenium cyclometallated (κ2-C,P) complexes (C3–C9) were obtained with phosphines containing a polycyclic aromatic substituent (L3-L9), namely 1-naphthyl, 9-phenanthryl or 1-pyrenyl. Some diastereoselectivity in the cyclometallation process has been observed for the most bulky ligands. The new compounds have been used as catalytic precursors in the reduction of acetophenone to 1-phenylethanol by transfer hydrogenation.

Solving ozone depletion and climate change problems require the development of effective methods for sustainably curbing them. With this aim, Milstein and coworkers developed a PNP pincer ruthenium catalyst for the homogeneous hydrogenation of nitrous oxide (N2O), an ozone-depleting substance and the third most important greenhouse gas, to generate dinitrogen and water as resultant products. The mechanism of this promising transformation was unveiled by means of experiments together with Density Functional Theory (DFT) calculations, which inspired Milstein and coworkers to use similar (PNN)Ru-H pincer catalysts for the reduction of N2O by CO to produce N2 and CO2. The use of the latter type of catalysts resulted in the proposition of a new reaction protocol and allowed to work under milder conditions. Here we describe the detailed mechanism of the last transformation catalyzed by a (PNN)Ru−H catalyst by means of DFT calculations, and not only this, but we also discover the way to block undesired parasitic reactions. Apart from that, we have explored a new evolution of this family of catalysts to go beyond previous experimental outcomes. The mechanism consists in a cascade of easy steps, starting from an insertion of the N2O oxygen into the Ru-H bond generating a hydroxo intermediate and releasing N2, and ending with a β-hydride elimination to form CO2 and regenerate the catalyst. The whole process occurs in a facile way with the exception of two steps: the formation of the hydroxyl ligand and the final β-hydride elimination to form CO2. However, the energy barriers of these two steps are not the bottleneck of the catalysis, but rather the easiness of the pyridyl group bonded to Ru to isomerize by C-H activation. We propose to solve this drawback by tuning the PNN ligand to block the pyridyl free rotation S.E. thanks Universitat de Girona and Donostia International Physics Center (DIPC) for an IFUdG2019 PhD fellowship. A.P. is a Serra Húnter Fellow. A.P. and M.S. thank the Ministerio de Economía y Competitividad (MINECO) of Spain for projects PGC2018-097722-B-I00 and CTQ2017-85341-P and the Generalitat de Catalunya for project 2017SGR39 and the ICREA Academia prize 2019 awarded to A.P. We thank Prof. David Milstein for helpful discussion

In the present work, a catalyst variation of the second-generation Hoveyda–Grubbs catalyst, particularly the ammonium-tagged Ru-alkylidene metathesis catalyst AquaMetTM, is under study, not simply to increase the efficiency in olefin metathesis but also the solubility in polar solvents. Moreover, this ionic catalyst was combined with the metal organic framework (MOF) (Cr)MIL-101-SO3−(Na·15-crown-5)+. We started from the experimental results by Grela et al., who increased the performance when the ruthenium catalyst was confined inside the cavities of the MOF, achieving non-covalent interactions between both moieties. Here, using density functional theory (DFT) calculations, the role of the ammonium N-heterocyclic carbene (NHC) tagged and the confinement effects are checked. The kinetics are used to compare reaction profiles, whereas SambVca steric maps and NCI plots are used to characterize the role of the MOF structurally and electronically This research was funded by the Ministerio de Economía y Competitividad (MINECO) of Spain for project PGC2018-097722-B-I00, the Generalitat de Catalunya for project 2017SGR39, and computer resources and technical support were provided by the Barcelona Supercomputing Center (BSC)

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2020, Tutor: Jaume Granell Sanvicente, The synthesis of different Schiff’s bases has been described in order to use them as ligand for the subsequent cyclometallation reaction. The cyclometallation reaction has been described starting with a half sandwich ruthenium complex, [RuCl2(p-cymene)2]2, and different benzylimines via ortho – CH activation. The reaction takes place at room temperature in methanol and in a short period of time (4 hours), using 2 equivalents of potassium acetate as deprotonation agent. This cyclometallation reaction leads the endo cyclometallated ruthenium product. The resultant N – Ru – C metallocycle compound is formed by a five-member ring containing the C = N bond. The molecular structures of each compound have been characterised by different spectroscopic techniques (IR, NMR and Mass) showing that the obtained product is in agreement with the proposed structures.

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2019, Tutor: Arnald Grabulosa Rodríguez, In this work, two differentiated blocks about the synthesis of complexes containing phosphine ligands presenting unconventional coordination modes are described. Following and adapting methods from literature, chelated palladium(II) complexes with general formula [Pd(3-2-methylallyl)(P*RR’CH2POR2- 2P*,O)](PF6) were synthesized. Starting from BH3-Pa, a P-stereogenic phosphine, chiral mono-oxidized diphosphine ligands were prepared and subsequently coordinated to Pd(II) centres by the splitting of a dimer complex of Pd(II), D0, resulting in two isomers of Pda. The corresponding chelated complexes were obtained from Pda, using halide scavengers to force the P*P(O) ligand to act as a bidentate, resulting in a five-membered ring metallocyclic cationic complexes, PdOa, which also presented two isomersThe synthesized ligands and complexes were characterized by 31P, 31P {1H} and 1H NMR. In the second part, the synthesis of four ruthenium complexes with general formula [RuCl2(6-arene)(P(PhPyr)R2)] and their derived two tethered complexes are described. 1-pyrenyl boronic acid was used as starting material to synthesize two phosphine ligands, PaPhPyr and PbPhPyr, which were coordinated to ruthenium centres by the splitting of two different metallic precursors, D1 and D2, obtaining Ru1a, Ru2a, Ru1b and Ru2b. Later, the corresponding tethered complexes were prepared under mild conditions by means of photochemical processes when they were just exposed to light of a common office lamp at room temperature, obtaining Rua’ and Rub’.The ligands and the complexes were characterized by 31P, 31P {1H}, 1H, 13C and 13C-1H gHSQC NMR, EA and HRMS, and also by XRD when it was possible.

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2019, Tutor: Arnald Grabulosa Rodríguez In this work, two differentiated blocks about the synthesis of complexes containing phosphine ligands presenting unconventional coordination modes are described. Following and adapting methods from literature, chelated palladium(II) complexes with general formula [Pd(3-2-methylallyl)(P*RR’CH2POR2- 2P*,O)](PF6) were synthesized. Starting from BH3-Pa, a P-stereogenic phosphine, chiral mono-oxidized diphosphine ligands were prepared and subsequently coordinated to Pd(II) centres by the splitting of a dimer complex of Pd(II), D0, resulting in two isomers of Pda. The corresponding chelated complexes were obtained from Pda, using halide scavengers to force the P*P(O) ligand to act as a bidentate, resulting in a five-membered ring metallocyclic cationic complexes, PdOa, which also presented two isomersThe synthesized ligands and complexes were characterized by 31P, 31P {1H} and 1H NMR. In the second part, the synthesis of four ruthenium complexes with general formula [RuCl2(6-arene)(P(PhPyr)R2)] and their derived two tethered complexes are described. 1-pyrenyl boronic acid was used as starting material to synthesize two phosphine ligands, PaPhPyr and PbPhPyr, which were coordinated to ruthenium centres by the splitting of two different metallic precursors, D1 and D2, obtaining Ru1a, Ru2a, Ru1b and Ru2b. Later, the corresponding tethered complexes were prepared under mild conditions by means of photochemical processes when they were just exposed to light of a common office lamp at room temperature, obtaining Rua’ and Rub’.The ligands and the complexes were characterized by 31P, 31P {1H}, 1H, 13C and 13C-1H gHSQC NMR, EA and HRMS, and also by XRD when it was possible.

L’estudi de sistemes basats en nanopartícules per a la catàlisi de les reaccions de reducció de protons a hidrogen (HER) i oxidació d’aigua a oxigen (OER) permet el disseny i desenvolupament de noves espècies catalítiques de manera racional, les quals poden millorar l’eficiència de la reacció de dissociació de l’aigua o “water splitting” (WS) per l’obtenció de H2, fent d’aquest procés una alternativa viable als combustibles fòssils. D’entre els metalls més utilitzats, el Pt i l’Ir són els que han donat millors resultats d’activitat i estabilitat per la HER i l’OER, respectivament. En aquest sentit, bona part d’investigació en el camp és dedicada a estudiar i entendre les interaccions que tenen part entre les diferents espècies durant la catàlisi, per poder transferir aquest coneixement a altres espècies basades en metalls més barats. El Ruteni podria ser una alternativa als metalls Pt/Ir, tenint en compte la seva versatilitat i la possibilitat que ofereix a ser estudiat mitjançant un ampli ventall de tècniques analítiques com a resultat de les seves propietats. L’objectiu d’aquesta tesis doctoral és el de desenvolupar nano-materials basats en Ru com a catalitzadors per a les reaccions de HER i OER, i estudiar-ne les característiques que indueixen una certa activitat catalítica. L’ús del mètode organometàl·lic com a procediment de síntesis de nanopartícules permet l’obtenció d’aquestes amb un control en les propietats que les defineixen com ara el diàmetre, l’entorn superficial o la dispersió. El mètode organometàl·lic permet l’addició d’agents coordinants a la mescla de reacció, els quals aturen la nucleació termodinàmica per formar un material “bulk” i estabilitzen la formació de partícules de mida nanomètrica. Aquestes espècies poden influenciar no només en la síntesi dels materials, sinó també a la reactivitat de les NPs, un efecte molt important pels processos catalítics en què poden estar involucrades. A més a més de la formació de partícules col·loïdals, una altra possibilitat que ofereix l’aproximació organometàl·lica és la síntesis de NPs a la superfície d’un suport com ara nanotubs de carboni, fibres, òxids metàl·lics, MOFs, etc. Aquest mètode va ser desenvolupat per primera vegada en el grup de recerca de la Dr. Philippot tres dècades enrere i actualment és àmpliament utilitzat per un número de grups d’investigació elevat. En resum, en aquesta memòria es descriu la síntesi de RuNPs per la seva avaluació com a catalitzadors per la HER i l’OER, amb l’objectiu d’entendre quines propietats de les NPs afecten els diferents passos catalítics i així ser capaços de dissenyar nous catalitzadors amb un millor rendiment catalític per la producció d’H2 a partir de l’aigua. The study of nanoparticulated systems for the hydrogen evolution (HER) and oxygen evolution (OER) reactions allows to rationally design new catalysts that enhance the water splitting process for obtaining H2, and thus making it a suitable alternative to fossil fuels as energy carriers. Nowadays Pt and Ir are the leading metals in HE and OE catalysts, respectively, but a huge effort is being devoted to understand the mechanistic pathways that rule both semi-reactions in order to transfer the knowledge to other metals which can be more abundant and thus cheaper. Ru appears as a feasible alternative to deeply explore the reaction steps involved in the process, because it is a highly-versatile metal which shows similar activities than Pt/Ir and which can be studied by a wide range of analytical techniques as a result of its properties. In addition, Ru is four times cheaper than the state-of-the-art Pt. This PhD work aims to develop Ru-based nanocatalysts for both HER and OER, and study the characteristics that induce a specific catalytic response. The use of the organometallic approach as synthetic methodology allows to finely control the properties of the NPs, e.g. size, surface environment, dispersion, etc. In this synthetic procedure, organic ligands can be added as stabilizing agents to halt the nucleation of metal atoms leading to the formation of the nanosized systems. These ligands can alter the chemical properties of the surface of the nanoparticles, a key feature in the catalytic processes. This methodology allows as well the preparation of metal nanoparticles onto the surface of solid supports, e.g. carbon nano-tubes, fibers, metal oxides, MOFs, etc. The organometallic approach was first developed in our group around three decades ago, and today its wide use by the global scientific community has brought a large knowledge on different nanometric systems. The development of precisely controlled nanocatalysts for their application in challenging catalysis like the production of H2 by water-splitting lies among our research interests. To sum up, the synthesis of Ru-NPs and their evaluation as catalysts for the HER and OER are described, aiming to understand the factors ruling the catalytic steps on the surface of the particles, to be able to rationally design new catalysts that make the water splitting process efficient enough to replace fossil fuels by H2.

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2018, Tutor: Arnald Grabulosa Rodríguez, The synthesis of eight Ru complexes with the general formula [RuI2(h6-arene)(PPyrR2)] (Pyr = 1-pyrenyl; arene = methyl benzoate or p-cymene), is described. These species were obtained from the parent dichlorocomplexes by treatment with an excess of sodium iodide in refluxing technical acetone for a period between 4 h and 11 days depending on the complex. Ru1-Ru4 stands for p-cymene complexes while Ru1’-Ru4’ are methyl benzoate complexes. Their structures were confirmed by IR, multinuclear NMR (31P, 1H, 13C), MS, EA and in three cases by single crystal X-ray diffraction. The antitumoral activity of these iodinated ruthenium complexes was studied against several cell lines and the results are promising compared to the chlorocomplexes. The synthesis of five new (1-pyrenyl)phosphines is also described. These ligands were designed taking into account the relation between the antitumoral activity and the bulkiness of the phosphines in dichlorocomplexes. The ligands have been obtained from the known dichlorophosphine L0. These phosphines were prepared adapting literature methods and have been characterised by the usual techniques.

Study of a batch of glasses of the High Roman Empire unearthed in the artisanal district of La Vayssière in L’Hospitalet-du-Larzac (Aveyron). This study has revealed, on the site, the presence of common glassware, typical of Western Roman productions. Moreover, many rare and semiluxurious glasses of Eastern, Italic, Northern and regional origins have been dug out. Considering the impressive variety of shapes, it highlights significant trade flows and it gives an overview of the use of glass in Rutene territory and southern Aquitaine., Étude d’un lot de verres du Haut-Empire mis au jour dans le quartier artisanal de La Vayssière à L’Hospitalet-du-Larzac (Aveyron). Celle-ci révèle la présence, sur le site, d’une verrerie commune, caractéristique des productions romaines occidentales, ainsi que celle de plusieurs verres rares et semiluxueux d’origine orientale, italique, septentrionale et régionale. La diversité des formes identifiées est remarquable et a permis de mettre en évidence d’importants flux d’échanges, donnant un aperçu de la consommation du verre en territoire rutène et au sud de l’Aquitaine., Brochot Marion. La consommation du verre dans le quartier périphérique de l’agglomération secondaire antique de La Vayssière (L’Hospitalet-du-Larzac, Aveyron). In: Aquitania : une revue inter-régionale d'archéologie, tome 32, 2016. pp. 195-214.

A new bis-facial dinuclear ruthenium complex, {[RuII(bpy)]2(μ-bimp)(μ-Cl)}2+, 22+, containing a hexadentate pyrazolate- bridging ligand (Hbimp) and bpy as auxiliary ligands has been synthesized and fully characterized in solution by spectrometric, spectroscopic, and electrochemical techniques. The new compound has been tested with regard to its capacity to oxidize water and alkenes. The in situ generated bis-aqua complex, {[RuII(bpy)(H2O)]2(μ-bimp)}3+, 33+, is an excellent catalyst for the epoxidation of a wide range of alkenes. High turnover numbers (TN), up to 1900, and turnover frequencies (TOF), up to 73 min−1, are achieved using PhIO as oxidant. Moreover, 33+ presents an outstanding stereospecificity for both cis and trans olefins toward the formation of their corresponding epoxides due to specific interactions transmitted by its ligand scaffold. A mechanistic analysis of the epoxidation process has been performed based on density functional theory (DFT) calculations in order to better understand the putative cooperative effects within this dinuclear catalyst Support form MINECO (Grants CTQ2011-26440, CTQ-2013-49075-R and CTQ2010-21532-C02-02) and the DFG (Grant Me1313/9-1) is gratefully acknowledged. J.A. is grateful for the award of a PIF doctoral grant from UAB. A.P. thanks the Spanish MINECO for the project CTQ2014-59832-JIN and the European Commission for a Career Integration Grant (No.CIG09-GA-2011-293900)

International audience; Compte-rendu de Master 2 réalisé sous la direction d’Emmanuelle Boube, maître de conférence en Archéologie romaine (UT2J / TRACES), et la co-direction de Marie-Thérèse Marty, ingénieure de recherche CNRS à TRACES (TRACES / UMR 5608, CNRS) Université Toulouse 2-Jean Jaurès, 2015.

The initiation mechanism of ruthenium methylidene complexes was studied detailing mechanistic insights of all involved reaction steps within a classical olefin metathesis pathway. Computational studies reached a good agreement with the rarely available experimental data and even enabled to complement them. As a result, a highly accurate computational and rather cheap recipe is presented A.P. thanks the Spanish MINECO for a Ramon y Cajal contract (RYC-2009-05226) and European Commission for a Career Integration Grant (CIG09-GA-2011-293900). E.P. gratefully acknowledges the receipt of the "Chemical Monthly Fellowship" financed by Springer Verlag, the Austrian Academy of Sciences (OAW), and the Gesellschaft Osterreichischer Chemiker (GOCH)

The effect of the PPh3 group in the antitumor activity of some new organometallic Ruthenium (II) complexes has been investigated. Several complexes of the type [Ru(II)(Cl)(PPh3)(Lig-N)], [Ru(II)(Cl)2(Lig-N)] (where Lig-N=pyridine derivate) and [Ru(II)(Cl)(PPh3)2], have been synthesized and characterized, and an important increment of the antitumor activity and cytotoxicity of the complexes due to the presence of PPh3 moiety has been demonstrated, affording IC50 values of 5.2 μM in HL-60 tumour cell lines. Atomic Force Microscopy, Circular Dichroism and Electrophoresis experiments have proved that these complexes can bind DNA resulting in a distortion of both secondary and tertiary structures. Ethidium bromide displacement Fluorescence Spectroscopy studies and Viscosity measurements support that the presence of PPh3 group induces intercalation interactions with DNA. Indeed, crystallographic analysis, suggest that intra-molecular π-π interactions could be involved in the intercalation within DNA base pairs. Furthermore, HPLC-MS studies have confirmed a strong interaction between Ruthenium complexes and proteins (Ubiquitin and Potato Carboxypeptidase Inhibitor -PCI-) including slower kinetic due to the presence of PPh3 moiety, which could have an important role in detoxification mechanism and others. Finally, Ion Mobility Mass Spectrometry (IMMS) experiments have proved that there is no change in the structural conformation of the proteins owing to their bonding to Ruthenium complexes. This seems particularly important in the case of PCI, that may be a suitable candidate for vehiculizing these complexes in a selective manner into tumour cells. In agreement with these results, further investigations should be carried out to clarify either there is a favoured binding to DNA or to specific proteins, thus to elucidate their main biological target.

Hydrolysis of different types of nitriles, such as acrylonitrile or benzonitrile, to selectively obtain the corresponding amides, has been successfully done using ruthenium catalysts such as [RuCl2(pypz-H)(DMSO)2], which eliminates the need for a base. In order to direct further optimization of the catalyst, the mechanism by which this reaction occurs has been studied. Based on the mechanisms proposed by Solomon et al. on the study of the nitrile hydratase, several possible routes of the ruthenium catalyst have been proposed. The viability of all of them have been studied and evaluated by computational calculations, determining the internal energy and the free energy in the aqueous phase. There have also been relevant calculations to determine which ligand dissociated to allow nitrile coordination, and if this varies depending on the route. In short, the main route of this reaction has been determined, as well as three possible secondary routes that could at least be competitive to the main one. At the same time, other species potentially present in the potential energy surface have been studied in order to determine their capability of decreasing the overall reaction rate and yield. These new insights may lead to future improvements of ruthenium catalysts for the nitriles hydrolysis

Density functional theory (DFT) calculations have been used to describe the first turnover of an olefin metathesis reaction calling for a new in silico family of homogenous Ru-based catalysts bearing a phosphine–phosphonium ylide ligand, with ethylene as a substrate. Equal to conventional Ru-based catalysts bearing an N-heterocyclic carbene (NHC) ligand, the activation of these congeners occurs through a dissociative mechanism, with a more exothermic first phosphine dissociation step. In spite of a stronger electron-donating ability of a phosphonium ylide C-ligand with respect to a diaminocarbene analogue, upper energy barriers were calculated to be on average ca. 5 kcal/mol higher than those of Ru–NHC standards. Overall, the study also highlights advantages of bidentate ligands over classical monodentate NHC and phosphine ligands, with a particular preference for the cis attack of the olefin. The new generation of catalysts is constituted by cationic complexes potentially soluble in water, to be compared with the typical neutral Ru–NHC ones Albert Poater thanks the Spanish Ministry of Economy and Competitiveness (MINECO) for a project CTQ2014-59832-JIN and Xarxa de Química Teòrica i Computacional for a VALCHEM2016 project

A new family of ruthenium complexes based on the N-pentadentate ligand Py2Metacn (N-methyl-N′,N′′-bis(2-picolyl)-1,4,7-triazacyclononane) has been synthesised and its catalytic activity has been studied in the water-oxidation (WO) reaction. We have used chemical oxidants (ceric ammonium nitrate and NaIO4) to generate the WO intermediates [RuII(OH2)(Py2Metacn)]2+, [RuIII(OH2)(Py2Metacn)]3+, [RuIII(OH)(Py2Metacn)]2+ and [RuIV(O)(Py2Metacn)]2+, which have been characterised spectroscopically. Their relative redox and pH stability in water has been studied by using UV/Vis and NMR spectroscopies, HRMS and spectroelectrochemistry. [RuIV(O)(Py2Metacn)]2+ has a long half-life (>48 h) in water. The catalytic cycle of WO has been elucidated by using kinetic, spectroscopic, 18O-labelling and theoretical studies, and the conclusion is that the rate-determining step is a single-site water nucleophilic attack on a metal-oxo species. Moreover, [RuIV(O)(Py2Metacn)]2+ is proposed to be the resting state under catalytic conditions. By monitoring CeIV consumption, we found that the O2 evolution rate is redox-controlled and independent of the initial concentration of CeIV. Based on these facts, we propose herein that [RuIV(O)(Py2Metacn)]2+ is oxidised to [RuV(O)(Py2Metacn)]2+ prior to attack by a water molecule to give [RuIII(OOH)(Py2Metacn)]2+. Finally, it is shown that the difference in WO reactivity between the homologous iron and ruthenium [M(OH2)(Py2Metacn)]2+ (M=Ru, Fe) complexes is due to the difference in the redox stability of the key MV(O) intermediate. These results contribute to a better understanding of the WO mechanism and the differences between iron and ruthenium complexes in WO reactions We thank the ICIQ Foundation, MEC for a FPU PhD grant FPU14/02550 (C.C.), the European Research Foundation for projects FP7-PEOPLE-2010-ERG-268445 (J.L.F.) and ERC-2009- StG-239910 (M.C.), the MICINN for project CTQ2009-08464 (M.C.) and for a Ramon y Cajal contract, the Generalitat de Catalunya for an ICREA Academia Award (M.C.) and the CELLEX Foundation through the CELLEX-ICIQ high-throughput experimentation platform for financial support. We also thank MINECO for support through Severo Ochoa Excellence Accreditation 2014–2018 (SEV-2013-0319). We acknowledge Catexcel for a generous gift of Ts3tacn

The synthesis via phosphine-boranes of 13 new optically pure P-stereogenic diarylphosphines P(Het)PhR (Het = 4-dibenzofuranyl (DBF), 4-dibenzothiophenyl (DBT), 4-dibenzothiophenyl-S,S-dioxide (DBTO2) and 1-thianthrenyl (TA); R = OMe, Me, i-Pr, Fc (ferrocenyl)) following the Jugé-Stephan method is described. The ligands were designed with the aim of having a heteroatom in a position capable of interacting with a metal upon coordination. The ligands and their precursors have been fully characterised, including the determination of two crystal structures of phosphine-boranes. Ru neutral complexes of the type [RuCl2(η(6)-arene)(κP-P)] (arene = p-cymene and methyl benzoate) have been prepared and characterised, including three crystal structure determinations. Treatment of solutions of the complexes with TlPF6 allowed the preparation of well-defined cationic complexes [RuCl(η(6)-arene)(κ(2)P,S-P)]PF6 for DBT- and TA-based phosphines. The complexes possess a stereogenic Ru atom and in most of the cases they are present as a single isomer in solution. All the Ru complexes have been used in the asymmetric transfer hydrogenation of acetophenone in refluxing 2-propanol, with good activities and up to 70% ee.

KGaA, Weinheim.Density functional theory calculations have been used to explore the potential of Ru-based complexes with 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (SIMes) ligand backbone (A) being modified in silico by the insertion of a C60 molecule (B and C), as olefin metathesis catalysts. To this end, we investigated the olefin metathesis reaction catalyzed by complexes A, B, and C using ethylene as the substrate, focusing mainly on the thermodynamic stability of all possible reaction intermediates. Our results suggest that complex B bearing an electron-withdrawing N-heterocyclic carbene improves the performance of unannulated complex A. The efficiency of complex B is only surpassed by complex A when the backbone of the N-heterocyclic carbene of complex A is substituted by two amino groups. The particular performance of complexes B and C has to be attributed to electronic factors, that is, the electronic-donating capacity of modified SIMes ligand rather than steric effects, because the latter are predicted to be almost identical for complexes B and C when compared to those of A. Overall, this study indicates that such Ru-based complexes B and C might have the potential to be effective olefin metathesis catalysts A.P. thanks the Spanish MINECO for a project CTQ2014-59832-JIN, and the European Commission for a Career Integration Grant (CIG09-GA-2011-293900)

Study of a batch of glasses of the High Roman Empire unearthed in the artisanal district of La Vayssière in L’Hospitalet-du-Larzac (Aveyron, France). This study has revealed, on the site, the presence of common glassware, typical of Western Roman productions. Moreover, many rare and semi-luxurious glasses of Eastern, Italic, Northern and regional origins have been dug out. Considering the impressive variety of shapes, it highlights significant trade flows and it gives an overview of the use of glass in Rutene territory and southern Aquitaine., Étude d’un lot de verres du Haut-Empire mis au jour dans le quartier artisanal de La Vayssière à L’Hospitalet-du-Larzac (Aveyron, 12). Celle-ci révèle la présence, sur le site, d’une verrerie commune, caractéristique des productions romaines occidentales, ainsi que celle de plusieurs verres rares et semi-luxueux d’origine orientale, italique, septentrionale et régionale. La diversité des formes identifiées est remarquable et a permis de mettre en évidence d’importants flux d’échanges, donnant un aperçu de la consommation du verre en territoire rutène et au sud de l’Aquitaine.

L’activació i funcionalització d’enllaços carboni-halogen poc reactius és un dels principals objectius de la química moderna. Els tres projectes d’investigació recollits en aquesta Tesi doctoral es centren en el desenvolupament de noves reaccions d’activació i trencament d’enllaços C-I, C-Br, C-Cl i C-F inerts. En el capítol 1 es descriu una nova transformació química, la síntesis catalitzada per Pd d’aroil acides a partir de iodoarens, CO i NaN3. Aquest procés catalític mostra una excel•lent eficiència (0.2% Pd) a més d’una excel•lent tolerància amb diferents grups funcionals. L’estudi del mecanisme de la reacció de acidocarbonilació ha permès demostrar l’existència de dos camins de reacció que tenen lloc en presencia de CO en excés i sota condicions de deficiència de CO. Els intermedis organometàl•lics implicats en el cicle catalític han estat aïllats i caracteritzats totalment, mitjançant diverses tècniques incloent difracció per raig X. El capítol 2 recull l’estudi del mecanisme de l’activació de Ph-X (X = I, Br, Cl) mitjançant complexes d’hidrur de Ru(II) utilitzant condicions extremadament suaus. Addicionalment, s’ha pogut demostrar que l’ordre zero observat en els estudis cinètics per a la reacció de [(Ph3P)4Ru(H)2] amb PhX (X = I, Br) troba el seu origen en un procés d’autocatàlisis poc evident. El capítol 3 es centra en la activació C-F del fortament inert fluoroform (CHF3), un gas subproducte industrial causant de l’efecte hivernacle, amb hidròxids i alcòxids de metalls alcalins. La reacció de MOR amb CHF3 condueix a la formació de ortoformiats, incloent l’exòtic en HC(OBu-t)3 amb excel•lents rendiments. Els resultats de la tesis han contribuït al desenvolupament de una nova metodologia, l’estudi de nous mecanismes de reacció i al desenvolupament de potencials solucions ecològiques., La activación y funcionalización de enlaces carbono-halógeno no reactivos es uno de los principales desafíos en la química moderna. Los tres proyectos de investigación que se abordan en esta Tesis Doctoral tratan sobre el desarrollo de nuevas reacciones de activación y rotura de enlaces no activados como C-I, C-Br, C-Cl y C-F. El capítulo 1 describe una nueva transformación, la síntesis de aroil azidas a partir de iodoarenos, CO y NaN3 catalizada por paladio. Este proceso catalítico muestra una alta eficiencia (0.2% Pd) y una excelente tolerancia a distintos grupos funcionales. La detallada investigación mecanística de la reacción de azidocarbonilación reveló la presencia de dos diferentes vías que operan en presencia de un exceso o defecto de CO. Los intermedios organometálicos implicados en el ciclo catalítico han sido aislados y completamente caracterizados, incluyendo difracción de rayos X. El capítulo 2 detalla un estudio mecanístico de la activación de Ph-X (X = I, Br, Cl) con complejos de hidruro de Ru(II) en condiciones extremadamente suaves. El inusual orden cero cinético de la reacción de [(Ph3P)4Ru(H)2] con PhX (X = I, Br) se origina debido a una autocatálisis que ha sido reconocida y completamente demostrada. El capítulo 3 describe la activación de los enlaces C-F altamente inertes del fluoroformo (CHF3), un gas de efecto invernadero producido industrialmente, con hidróxidos y alcóxidos de metales alcalinos. La reaciión de MOR con CHF3 se ha demostrado para dar lugar a los correspondientes ortoformiatos, incluído el exótico HC(OBu-t)3, en rendimientos excelentes. Los resultados de la Tesis Doctoral contribuyen al desarrollo de nuevas metodologías, al conocimiento básico de mecanismo de reacción y a posibles soluciones ecológicas., Activation and functionalization of unreactive carbon-halogen bonds is one of the primary tasks of modern chemistry. All three research projects fulfilled in the current Thesis deal with new reactions involving activation and cleavage of highly inert C-I, C-Br, C-Cl, and C-F bonds. Chapter 1 describes a new chemical transformation, Pd-catalyzed synthesis of aroyl azides from iodoarenes, CO, and NaN3. This catalytic process exhibits high efficiency (0.2% Pd) and excellent functional group tolerance. A detailed mechanistic study of the azidocarbonylation reaction has revealed two different reaction pathways operating in the presence of CO in excess and under CO-deficient conditions. Organometallic intermediates involved in the catalytic cycle have been isolated and fully characterized, including by X-ray diffraction. Chapter 2 reports a mechanistic study of the novel Ph-X (X = I, Br, Cl) activation with Ru(II) hydrido complexes under exceedingly mild conditions. Striking zeroth-order kinetics observed for the reaction of [(Ph3P)4Ru(H)2] with PhX (X = I, Br) originates from hidden autocatalysis that has been recognized and fully proven. Chapter 3 deals with C-F activation of highly inert fluoroform (CHF3), an industrially side-produced potent greenhouse gas, with alkali metal hydroxides and alkoxides. The reaction of MOR with CHF3 has been shown to furnish the corresponding orthoformates, exotic HC(OBu-t)3 included, in good to excellent yield. Results of the Thesis contribute to new methodology development, basic knowledge of reaction mechanisms, and potential ecological solutions.

En aquesta tesi doctoral s’han preparat una sèrie de complexos de ruteni(II) amb lligands heterobidentats P-,N-donadors i s’ha estudiat la seva activitat catalítica en les reaccions de transferència d’hidrogen per a la reducció de cetones amb isopropanol i l’alquilació d’amines amb alcohols. Els lligands sintetitzats són del tipus fosfinoamina, aminofosfinoimida i fosfinoimida. Aquests formen enllaços quelats de cinc o sis baules, depenent del seu esquelet, amb l’ió Ru(II). Els complexos sintetitzats són bàsicament de dos tipus: una família conté, a banda del lligand P-,N-donador, un lligand ƞ5-ciclopentadienil i una PPh3 o un lligand cloro; l’altre família de complexos, de geometria octaèdrica, conté dos lligands P-,Ndonadors i dos cloro que completen l’estructura. Tots aquests complexos presenten activitat catalítica en les reaccions de transferència d’hidrogen amb isopropanol per a la reducció de diferents cetones aromàtiques i alifàtiques. Els complexos també han demostrat ser actius per l’alquilació d’amines alifàtiques i aromàtiques amb diferents alcohols., In this PhD thesis a series of ruthenium (II) complexes with P-,N-donor ligands has been prepared. The catalytic activity of these complexes has been studied in hydrogen transfer reactions with isopropanol for reduction of ketones and the alkylation of amines with alcohols has been shown. The ligands synthetized are of phosphineamine, aminephosphineimide and phosphinoimide type. They form five and six membered chelated rings with the Ru(II) ion, depending on its backbone. The complexes synthesized are of two types: one family contains, in addition to the P-,N-donor ligand, one ƞ5-cyclopentadienyl and one PPh3 or chloro ligand; the other family of complexes contains two P-,N-donor ligands and two additional chloro to complete the octahedral geometry. All these complexes are active in hydrogen transfer reactions with isopropanol for the reduction of various aliphatic and aromatic ketones. The complexes also show activity for the alkylation of aromatic and aliphatic amines with different alcohols.

SPN thanks the European Research Council(227817) (Advanced Investigator Award ‘FUNCAT’), the EU(CP-FP 211468) (Seventh Framework Programme Project ‘EUMET’), and the Engineering and Physical Sciences Research Council for funding. SPN is a Royal Society Wolfson Merit Award holder. AP thanks the Spanish MINECO for a Ramón y Cajal contract (RYC-2009-05226) and European Commission for a Career Integration Grant (CIG09-GA-2011-293900). The commercially-available metathesis pre-catalyst M23 has been evaluated alongside new complex [RuCl2((3-phenyl)indenylidene)(PPh3)(SIPrOMe)] (1), which bears a para-methoxy-substituted N-heterocyclic carbene ligand. Several model metathesis reactions could be conducted using only parts-per-million levels of ruthenium catalyst. The effects of the different NHC ligands on reactivity have been explored. Postprint

Compte-rendu de Master 2 réalisé sous la direction d’Emmanuelle Boube, maître de conférence en Archéologie romaine (UT2J / TRACES), et la co-direction de Marie-Thérèse Marty, ingénieure de recherche CNRS à TRACES (TRACES / UMR 5608, CNRS) Université Toulouse 2-Jean Jaurès, 2015.

Thanks to the experience of the research group in the synthesis of ruthenium complexes with dmso and N-donor ligands and their application in catalysis, in this work we have developed new ruthenium complexes using N-donor ligands that have been subsequently evaluated as catalysts for the nitrile hydrolysis reaction. First, two new ruthenium complexes ([2] and [3]) with one or two pzph-OH ligand have been synthesized, together with a ruthenium complex ([4]) with the terpyridine ligand, in all cases with dmso and Cl ligands. The complexes have been characterized using different spectroscopic and electrochemical techniques. With respect to structural characterization, the formation of a single isomer for [2] and [3] complexes has been shown. It should be noted that in the case of complex [2] the crystal structure has been obtained that has been solved by X-ray diffraction analysis. The characterization of complex [4] has also been carried out for one of the isomers that has been obtained in pure form. It should be mentioned that in this case, it is observed the formation of a second isomer for longer reaction times. UV-Vis spectra have been performed in methanol for complexes [2] and [3] and dichlormetane for the [4] complex, where the presence of MLCT and intraligand π-π * bands it evidenced in the three cases, and the corresponding extinction coefficients could be calculated. For complexes [2] and [3] a wavelength shift along the time is observed, possibly due to exchange of one ligand by methanol. Subsequently, the electrochemical properties of the three complexes have been studied by cyclic voltammetry (CV). For complex [2], a reversible wave corresponding to the Ru(III/II) redox pair has been observed. On the contrary, complex [3] exhibits an irreversible wave due to a Ru-dmso bond isomerization process. To demonstrate this fact, an electrochemical study of the two mentioned complexes has been carried out, which has cofirmed that the isomerization process is shown only by complex [3]. Moreover, we also registered the CVs for complex [4], which exhibits a reversible wave; a second wave was observed for longer reaction times evidencing once again the formation of a second isomer. Finally, the catalytic activity in the hydrolysis of nitriles of the complex [3] and [4] has been evaluated using two different substrates, obtaining moderate to high conversions and excellent selectivity for the amide product

DFT calculations have been used to determine the thermodynamic and kinetic preference for ruthenacyclobutanes resulting from the experimentally proposed interconversion pathways (olefin and alkylidene rotations) through the investigation of cross-metathesis reaction mechanism for neutral Grubbs catalyst, RuCl2(=CHEt)NHC (A), with ethylene and 1-butene as the substrates. Our results show that although the proposed interconversions are feasible due to the predicted low energy barriers (2-6 kcal/mol), the formation of ruthenacyclobutane is kinetically favored over the competitive reactions involving alkylidene rotations. In comparison with catalyst A, the reaction energy profile for cationic Piers catalyst [RuCl2(=CHPCy3)NHC+] (B) is more endothermic in nature with both ethylene and 1-butene substrates A.P. thanks the Spanish MINECO for a Ramón y Cajal contract (RYC-2009-05226) and a José Castillejo fellowship (CAS14/00165), and European Commission for a Career Integration Grant (CIG09-GA-2011-293900)

In this work, we present the synthesis and characterization of new ruthenium complexes with the idea of studying their coordination chemistry, as well as their performance in nitrile hydration reactions. We describe the synthesis and the spectroscopy and redox characterization of new ruthenium compounds, Ru-Cl and Ru-DMSO. These complexes contain the neutral 1,4,7– trithiacyclononane (9S3) and the non-symmetric didentate 2-(3-pyrazolyl)pyridine (pypz- H) ligands. Firstly, we have synthesized the complex [RuIICl2(DMSO)4] [1] and [RuIICl2(9S3)(DMSO)] [2]. Both have been used as starting material for the synthesis of chlorido complex [RuIICl(pypz-H)(9S3)]Cl [3]. Moreover, complex [RuII(9S3)(pypz)(DMSO)](PF6)2 [4] have been also synthesized from complex [3] by replacing chlorido ligand (Cl) by dimethyl sulfoxide ligand (DMSO). The new complexes have been characterized in solid state through elemental analysis and infrared spectroscopy (IR) and in solution through spectroscopic techniques as nuclear magnetic resonance (NMR), ultraviolet visible (UV-Vis) and cyclic voltammetry (CV). The chemical behavior in aqueous solution has been tested for the two complexes Ru-Cl [3] and Ru-DMSO [4] through UV-Vis. In both cases, substitution of chlorido and DMSO ligands for aqua ligand has been observed and consequently we have studied the kinetics of aquation for both complexes. We also have studied the pH-dependent redox properties for the resulting aqua ruthenium complex through a Pourbaix diagram. Finally, the catalytic activity of the complexes in nitrile hydration reaction is evaluated in water using nitriles like benzonitrile and acrylonitrile as substrates. All compounds have shown moderate conversions and high selectivities values towards the corresponding amides

The synthesis of five optically pure P -stereogenic monophosphines of the type PPhArR (Ar = 2- p -terphenylyl ( a ), 1-pyrenyl ( b ); R = OMe, Me, i -Pr) is described. The ligands were fully characterised and the absolute configurations of PPh(1-pyrenyl)R ( 3b and 5b ; R = OMe and Me respectively) were confirmed by X-ray diffraction. The complexation of the monophosphines to Pd and Ru organometallic units yielded the neutral complexes [PdCl(η 3 -2-Me-allyl)P] ( 10–12 ) and [RuCl 2 (η 6 - p -cymene)P] ( 16–18 ). Complete characterisation, including the crystal structure determination of [RuCl 2 (η 6 - p -cymene)(PMePh(2- p -terphenyl))] ( 17a ) is provided. Neutral palladium complexes appeared as mixtures of two diastereomers in solution according to NMR. The synthesis and characterisation of four cationic [Pd(η 3 -2-Me-allyl)( P ) 2 ]PF 6 ( 13 and 14 ) is also described. The application of neutral Pd complexes to catalytic styrene hydrovinylation afforded moderate conversions, high chemoselectivities (>92%) to 3-phenyl-1-butene and up to 43% ee with precursor 12a . Cationic Pd complexes were tested as catalytic precursors in allylic substitution of rac -3-acetoxy-1,3-diphenyl-1-propene ( rac -I ), with the anion of dimethylmalonate and benzylamine as nucleophiles, obtaining full conversions and up to 80% ee in alkylation and 60% ee in amination with precursor 13a . Finally, ruthenium complexes were used as catalytic precursors in transfer hydrogenation of acetophenone, with complete conversions after several hours but low enantioselectivities.

Aquest mateix article està publicat a l'edició alemanya d''Angewandte Chemie' (ISSN 0044-8249, EISSN 1521-3757), 2014, vol. 126, núm. 34, p. 9141–9145. DOI http://dx.doi.org/10.1002/ange.201403770 The decomposition of a series of benzylidene, methylidene, and 3-phenylindenylidene complexes has been probed in alcohol solution in the presence of base. Tricyclohexylphosphane-containing precatalysts are shown to yield [RuCl(H)(H2)(PCy3)2] in isopropyl alcohol solutions, while 3-phenylindenylidene complexes lead to η5-(3- phenyl)indenyl products. The potential-energy surfaces for the formation of the latter species have been probed using density functional theory studies

Ru-aqua complex {[RuII(trpy)(H2O)] 2(μ-pyr-dc)}+ is a powerful epoxidation catalyst for a wide range of linear and cyclic alkenes. High turnover numbers (TNs), up to 17000, and turnover frequencies (TOF), up to 24120 h-1 (6.7 s -1), have been obtained using PhIO as oxidant. This species presents an outstanding stereospecificity for both cis and trans olefins towards the formation of their corresponding cis and trans epoxides. In addition, it shows different reactivity to cis and trans olefins due to a substrate orientation supramolecular effect transmitted by its ligand scaffold. This effect together with the impressive reaction rates are rationalized using electrochemical techniques and DFT calculations. A new Ru-aqua complex that behaves as a powerful epoxidation catalyst for a wide range of linear and cyclic alkenes is reported. High turnover numbers and frequencies are obtained by using PhIO as oxidant. The complex shows an outstanding stereospecificity for both cis and trans olefins towards the formation of their corresponding cis and trans epoxides This research was supported financially by MINECO (CTQ2011-23156/BQU, CTQ2010-21497 and PRI-PIBIN-2011-1278), ICIQ, FEDER fund (UNGI08-4E-003), ICREA Academia, Generalitat de Catalunya (2009SGR637); Ramon y Cajal contract (RYC-2009-05226) of MINECO, and Career Integration Grant (CIG09-GA-2011-293900) of the European Commission. COST Actions CM1205 and CM1202 are also gratefully acknowledged

[RuCl(η5-3-phenylindenyl)(PPh3)2] (1) has been shown to be a highly active catalyst for the isomerisation of allylic alcohols to the corresponding ketones. A variety of substrates undergo the transformation, typically with 0.25-0.5 mol% of catalyst at room temperature, outperforming commonly-used complexes such as [RuCl(Cp)(PPh3) 2] and [RuCl(η5-indenyl)(PPh3) 2]. Mechanistic experiments and density functional theory have been employed to investigate the mechanism and understand the effect of catalyst structure on reactivity. These investigations suggest a oxo-π-allyl mechanism is in operation, avoiding intermediate ruthenium hydride complexes and leading to a characteristic 1,3-deuterium shift. Important mechanistic insights from DFT and experiments also allowed for the design of a protocol that expands the scope of the transformation to include primary allylic alcohols We thank the ERC (Advanced Investigator Award ` FUNCAT' to SPN) and the EPSRC for funding. Umicore is thanked for gi. s of materials. SPN is a Royal Society Wolfson Merit Award holder. Melanja Smith and Dr Tomas Lebl are thanked for assistance with NMR spectroscopy facilities. Dr Cesar A. Urbina-Blanco is acknowledged for useful discussions. LC thanks the HPC team of Enea for using the ENEA-GRID and the HPC facilities CRESCO in Portici (Italy) for access to remarkable computational resources. AP thanks the Spanish MICINN for a Ramon y Cajal contract (RYC-2009-05226) and European Commission for a Career Integration Grant (CIG09-GA-2011-293900)

An olefin metathesis catalyst featuring a SIPr NHC and an ester chelating carbene ligand is introduced. In contrast to its previously published SIMes analogue, only the trans dichloro configurated isomer was obtained. The two counterparts are tested in various olefin metathesis reactions, revealing a striking superiority of the new complex in the cross metathesis of olefins with methyl vinyl ketone allowing for full conversion with only 500 ppm catalyst loading Financial support of this work from the Higher Education Commission of Pakistan (for M. A.) and the European Community (CP-FP 211468-2 EUMET) is gratefully acknowledged. A. P. thanks the Spanish MINECO for a Ramon y Cajal contract (ref. RYC-2009-05226) and the European Commission for a Career Integration Grant (CIG09-GA-2011-293900)

Un dels principals mètodes per a sintetitzar productes enantiomericament purs és la catàlisi asimètrica utilitzant compostos organometàl•lics quirals. En aquesta estrategia, el disseny i preparació de lligands quirals és molt important. En aquest context, nosaltres hem desenvolupat nous lligands quirals per diverses reaccions de catàlisi asimètrica. Concretament ens hem centrat en: (a) L’aplicació d’una llibreria de lligands fosfit-fosforoamidit i difosforoamidit derivats de carbohidrats en la hidrogenació de olefines proquirals. Aquests lligands han donat excel•lents enantioselectivitats (up to >99% ee). (b) L’aplicació de les llibreries de lligands tioèter-fosfit, tioèter-fosfinit i tioèter-fosforoamidit derivats de carbohydrats en la hidrogenació catalitzada per iridi de olefins no funcionalitzades i en reaccions de substitució al•lílica catalitzada per paladi. Els resultats obtinguts en hidrogenació competeixen favorablement amb els millors resultats publicats prèviament. (c) L’aplicació de llibreries de lligands pseudo-dipèptids i tioamides derivats de carbohidrats en transferència d’hidrogen de cetones. Els resultats obtinguts, novament competeixen favorablement amb els publicats anteriorment obtenint excel•lents enantioselectivitats (up to 99%) per un ampli rang de substrats., One of the main methods for producing enantiomerically pure compounds is metal asymmetric catalysis. An important step in this strategy is the design and preparation of chiral ligands. In this context, we have developed new chiral ligands for several important asymmetric catalytic reactions. Specifically we have focused on: (a) The application of a furanoside phosphite-phosphoroamidite and diphosphoroamidite ligand library in the hydrogenation of prochiral olefins. These ligands have provided excellent enantioselectivities (up to >99% ee). (b) The application of furanoside thioether-phosphite, thioether-phosphinite and thioether-phosphoroamidite ligand libraries in the challenging Ir-catalyzed hydrogenation of unfunctionalized olefins and in Pd-allylic substitution reactions. The results in hydrogenation compete favourable with the best ones previously reported. (c) The application of carbohydrate-based pseudo-dipeptide and thioamide ligand libraries in transfer hydrogenation of ketones. The results again compete favourable with the best one previously reported. Unprecedent enzyme-like behaviour has been obtained, providing ee’s up to 99% for a wide range of substrates.

A photoactivated ruthenium(II) arene complex has been conjugated to two receptor-binding peptides, a dicarba analogue of octreotide and the Arg-Gly-Asp (RGD) tripeptide. These peptides can act as "tumor-targeting devices" since their receptors are overexpressed on the membranes of tumor cells. Both ruthenium-peptide conjugates are stable in aqueous solution in the dark, but upon irradiation with visible light, the pyridyl-derivatized peptides were selectively photodissociated from the ruthenium complex, as inferred by UV-vis and NMR spectroscopy. Importantly, the reactive aqua species generated from the conjugates, [(η(6)-p-cym)Ru(bpm)(H(2)O)](2+), reacted with the model DNA nucleobase 9-ethylguanine as well as with guanines of two DNA sequences, (5')dCATGGCT and (5')dAGCCATG. Interestingly, when irradiation was performed in the presence of the oligonucleotides, a new ruthenium adduct involving both guanines was formed as a consequence of the photodriven loss of p-cymene from the two monofunctional adducts. The release of the arene ligand and the formation of a ruthenated product with a multidentate binding mode might have important implications for the biological activity of such photoactivated ruthenium(II) arene complexes. Finally, photoreactions with the peptide-oligonucleotide hybrid, Phac-His-Gly-Met-linker-p(5')dCATGGCT, also led to arene release and to guanine adducts, including a GG chelate. The lack of interaction with the peptide fragment confirms the preference of such organometallic ruthenium(II) complexes for guanine over other potential biological ligands, such as histidine or methionine amino acids.

Una de les estratègies en el campde la fotosíntesis artificial consisteix en un sistema modular en que els diferents components indispensables d’un un aparell funcional són estudiats de manera independent per al seu futur acoblament. Aquesta tesi s’ha centraten la sintesis i caracterització d’una sèrie de nous compostos mono- i dinuclears de ruteni amb lligands de tipus polipiridil. S’ha estudiat l’aplicabilitat d’aquests nous compostos com a catalitzadors en processos tant importants com son l’oxidació d’ aigua a oxigen molecular i la reduccio de diòxid de carboni a àcid fòrmic. També, s’han estudiat en gran detall les propietats d’origen supramolecular detectades en els compostos dinuclears, fomentat per la directa implicació d’aquest tipus d’interaccions en els processos catalítics estudiats., Artificial photosynthesis seeks to functionally mimik the photosynthetic process carried out by nature, and combine the energy from the sun with water to obain a “solar” fuel like hydrogen. One of the strategies in the field, consists on a modular approach in which all the components needed are studied independently, in view of their future assembly in a final operative device. This thesis has been focused on the synthesis and characterization of a series of new mono and dinuclear ruthenium componud with polylpyridylic ligands. The aplication of these new compounds as catalysts in very important processes such as water oxidation and CO2 reduction has been studied. Additionally, the suprmolecular properties detected in the dinuclear compounds has been studied in great detail, which has been promoted by the direct implication of such type of interactions in the catalytic processes studied.

This article deals with a Celtic independant coinage which appears to have had a limited distribution, in an area later included in the territory of the Colonia Baeterrensis created in BC 35/36. The distribution of these coins fits within the limits of the Beziers territory, except to the North-East where it also concerns the later civitas of Luteva. It does seem to have been struck and distributed by a Celtic tribe, member of the Ruteni, but whose name is up to now unknown. When the Southern part of the Ruteni territoty was put under Roman authority (c. 80/70 BC), the area may have been ruled by Narbonne. But later in 35/36, the Beziers territory was made from different earlier territories, including Agde, the former Beziers kingdom and Southern Ruteni sub-tribes, including the one studied here., Une série de monnaies gauloises en argent, portant au revers un cheval surmonté d'un fleuron, ne semble avoir été diffusée que dans une partie très limitée de l'actuel département de l'Hérault. Excluant les territoires de la plaine littorale, qui devaient dépendre à la fin de l'Age du Fer de Béziers et d'Agde, cette distribution ignore également la partie septentrionale du futur territorium de la cité de Béziers., ainsi que la zone qui deviendra le territoire de Luteva, à l'exception notable du bassin de Gignac. On peut donc considérer qu'en 36 av. n. ère, la communauté émettrice, dont nous ignorons le nom et même la capitale (à moins que ce ne soit Piscinae... ?) a été intégrée dans la colonia baeterrensis en même temps que les anciens territoires du littoral (la Betarra préromaine) ainsi que ceux de l'arrière-pays qui avaient été pris aux Ruteni. Le territoire de la civitas aurait donc été formé en agglomérant, selon plusieurs logiques, des amis et d'anciens ennemis. Le statut d'oppidum latinum pourrait alors témoigner des faveurs accordées aux uns (Cessero) pour les distinguer des autres (Ruteni).

Síntesi de nous complexos de Ruteni amb lligands no quirals que tenen per fórmula [Ru(phen)([9]aneS3)X] (on X = H2O, py i MeCN). Caracterització espectroscòpica electroquímica i estructural d'aquesta família de complexos. Estudi de les seves propietats catalítiques en front a l'oxidació de substrats orgànics com l'alcohol benzílic en reaccions d'electrocatàlisi. Avaluació cinètica dels mecanismes de substitució entre els complexos Ru-py i Ru-MeCN. Generació d'un interruptor molecular foto-induït.Síntesi de nous complexos quirals de Ru atropoisomèricament purs amb lligands oxazolínics que tenen per fórmula [Ru(trpy)(Ph-box-R)X] on (X = Cl, H2O, py, MeCN, 2-OH-py). Caracterització estructural exhaustiva en estat sòlid (Raig-X) en solució (RMN) i en fase gas (càlculs DFT). Avaluació de la seva activitat catalítica en reaccions asimmetriques d'epoxidació de substrats proquirals.Síntesi de nous lligands polipiridílics quirals amb simetria C3. Estudi de la seva química de coordinació i avaluació de la seva activitat catalítica en reaccions asimmetriques d'oxidació i reducció., Synthesis, spectroscopic characterization and redox properties of a new Ru-H2O complex containing 1,10-phenantroline and the soft [9]aneS3 ligand. Substitution pathways of a new Ru-py complex [Ru(phen)(py)([9]aneS3)]2+ to form the corresponding Ru-MeCN complex through kinetic analysis. Kinetic establishment of a reaction intermediate. Synthesis of new Ru(II) complexes containing the chiral 1,2-bis(oxazolinyl) benzene ligand. Rotationally restricted isomers were produced upon coordination to a ruthenium metal centre. Atropisomeric discrimination was observed due to steric effects between the oxazolinic and the auxiliary ligands. Evaluacion of the catalytic activity of the family of complexes in C=C double bond epoxidations.Development of new synthetic routes toward chiral "pineno-fused" N-donor ligands. Synthesis of Ru(II) complexes containing different combinations of these new ligands with other non-chiral N-N or p-P compounds. Evaluacion of the catalytic activity of these complexes in catalytic oxidation (epoxidations) and reductions (hydrogenation and transfer hydrogenation) of C=C double bonds.

Aquesta tesi és el reflex que de la cooperació entre grups experimentals i grups teòrics s'aconsegueix l'assoliment d'objectius inassolibles de forma individual. A partir de la DFT s'expliquen processos inorgànics i organometàl·lics de gran valor biològic i/o industrial. La tesi està enfocada especialment a l'estudi de complexos mononuclears i binuclears de coure, on té lloc l'activació d'enllaços C-H, C-C, i O-O. L'estudi de complexos octaèdrics de ruteni ha permès dur a terme extensos estudis isomèrics i racionalitzar les propietats espectroscòpiques dels mateixos. A més a més, estudis més puntuals respecte clusters de coure, l'estudi de la reacció de Pawson-Khand, l'estudi d'enllaços Pt-Pt en complexos trimèrics de platí, a més a més de l'estudi de la isomeria de complexos de Ni i Pt., This thesis shows that the cooperation between experimental and theoretical groups gives as a result the achievement of aims impossible working independently. From DFT calculations inorganic and organometallic problems related to great biological and industrial processes can be explained. This thesis is especially focused on the study of mononuclear and binuclear copper complexes, where a C-H, C-C, and O-O bond activation takes place. The study of octahedral ruthenium complexes has allowed carrying out isomeric studies and the rationalization of spectroscopic properties. Furthermore, other little studies related to copper clusters, the Pawson-Khand reaction, Pt-Pt bond interaction in trimer platinum complexes, and isomerism of Ni and Pt complexes.

Aquesta tesi doctoral es basa en l'estudi de l'aplicació en catàlisi de dos tipus de complexos organometallics basats en dos metalls de tansició diferents. Concretament s'estudien complexos macrocíclics triolefínics de pal·ladi(0) com a catalitzadors per a les reaccions de Suzuki i Heck, i oxocomplexos carbènics de ruteni(II) com a espècies catalítiques en oxidacions de compostos orgànics. En el cas dels complexos de ruteni s'ha vist que en augmentar el nombre de lligands carbènics en l'esfera de coordinació del metall s'aconseguiex afavorir els processos bielectrònics, obtenint-se catalitzadors més actius i més selectius.En un segon pas, els dos tipus de catalitzadors homogenis s'han immobilitzat sobre la superfície d'un elèctrode mitjançant l'estratègia d'electropolimerització del grup pirrol. Els elèctodes modificats resultants s'han aplicat com a catalitzadors heterogenis. En ambdós casos els catalitzadors heterogenis han mostrat una activitat equiparable o superior a la del sistema homogeni corresponent.Finalment, s'ha assajat una reacció de catàlisi tàndem en què els dos catalitzadors (immobilitzats sobre el mateix elèctrode) actuen en cooperació. S'ha aconseguit realitzar dues transformacions consecutives d'un substat orgànic., This thesis studies the application in catalysis of two types of organometallic complexes based on two different transition metals. Concretely, we have studied the application of palladium triolefinic macrocyclic complexes as catalysts in the Suzuki and Heck reactions, and the application of ruthenium carbenic aquacomplexes as catalysts in the oxidation of organic substrates. For Ru complexes we have seen that the more carbenic groups in the coordination sphere, the more favored is a bielectronic process, that meaning a better catalytic activity and selectivity.In a second step, both catalysts have been immobilized on an elecctrode surface by pyrrole electropolymerization. The resulting modified electrodes have been used as heterogeneous catalysts, showing a similar or a better activity that the corresponding homogeneous systems.Finally, We have designed and tested a tandem reaction with both catalysts (immobilized on the same electrode) acting in cooperation. We have been able to realize two consecutive transformations of an organic substrate.

Se han sintetizado dos nuevos complejos mononucleares de Ru, con formula [RuCl2(Hbpp)(dmso)2], a partir de la reacción entre [RuCl2(dmso)4] y Hbpp (3,5-bis(2-piridil)pirazola). El hecho que sólo tres de los seis posibles estereoisómeros se obtengan a partir de esta reacción, se ha racionalizado en base a factores estructurales y electrónicos. Estos complejos se han caracterizado de forma estructural, espectroscópica y electroquímica. En acetonitrilo en medio básico, el isómero trans,cis-[RuCl2(Hbpp)(dmso)2] da lugar a procesos de isomerización de enlace de un ligando dmso cuando el Ru(II) se oxida a Ru(III). Las constantes termodinámicas y cinéticas para el proceso se han determinado por voltametria cíclica. La irradiación de trans,cis-[RuCl2(Hbpp)(dmso)2] y cis(out),cis-[RuCl2(Hbpp)(dmso)2] con luz UV o solar da lugar a reacciones de fotosustitución de un ligando dmso por una molécula de acetonitrilo para dar un nuevo compuesto el cual ha sido caracterizado en solución por técnicas espectroscópicas y electroquímicas. Ambos complejos resultan catalizadores útiles en la transferencia de hidrógeno de isopropanol a acetofenona, obteniéndose 1-feniletanol como único producto y un 42.1% de conversión (36.1 ciclos metálicos) a 80ºC con el isómero trans,cis-[RuCl2(Hbpp)(dmso)2], que resulta significativamente más eficaz que el complejo cis(out),cis-[RuCl2(Hbpp)(dmso)2].La reacción de cis(out),cis-[RuCl2(Hbpp)(dmso)2] con trpy (2,2':6',2"-terpiridina) da lugar a los dos isómeros geométricos del complejo [Ru(Hbpp)(trpy)(Cl)]+, el in y el out. Estos complejos se han aislado y caracterizado por técnicas estructurales, espectroscópicas y electroquímicas. Estos cloro complejos han sido utilizados como precursores para la síntesis de los complejos análogos con ligandos aqua (in,out-[Ru(Hbpp)(trpy)(H2O)]2+) y piridina (in,out-[Ru(Hbpp)(trpy)(py)]2+), los cuales también han sido aislados y caracterizados. Las propiedades ácido-base de los aqua complejos, y del complejo out-py se han estudiado detalladamente por voltametria cíclica y mediante valoraciones espectrofotométricas ácido-base. El tratamiento matemático de los datos así obtenidos nos ha permitido determinar los valores de pKa para los distintos equilibrios de protonación de los complejos en los estados de oxidación II y III. El complejo out-aqua ha demostrado ser un buen catalizador para la oxidación electroquímica del alcohol benzílico, presumiblemente a benzaldehido. La constante de velocidad de segundo orden para el proceso ha sido determinada como 17.1 M-1 s-1, por simulación matemática.El dímero con un puente cloro, [Ru2Cl(bpp)(trpy)2]2+ ha sido preparado por dos rutas sintéticas diferentes. El dímero análogo con un puente acetato se ha obtenido por reacción del cloro dímero con un exceso de acetato sódico. El dímero con dos ligandos aqua [Ru2(bpp)(trpy)2(OH2)2]3+ puede obtenerse por hidrólisis ácida del complejo con un acetato puente o por hidrólisis básica del complejo con un puente cloro. Estos complejos han sido caracterizados por técnicas estructurales, espectroscópicas y electroquímicas. Las soluciones del dímero con dos ligandos aqua en medio ácido resultan inestables a la coordinación de aniones de la solución con el tiempo. Las propiedades ácido-base del dímero con dos aguas coordinadas han sido estudiadas por voltametria cíclica y mediante experimentos de electrólisis a potencial controlado. El pKa para la desprotonación de uno de los ligandos aqua ha sido determinado mediante una valoración espectrofotométrica ácido-base como 6.7. Este valor tan bajo de pKa se atribuye a la formación de la entidad {Ru2O2H3}, favorable termodinámicamente. Los espectros UV-vis para los distintos estados de oxidación del aqua dímero, de RuIIRuII a RuIIIRuIV, han sido obtenidos por oxidación química y electroquímica del complejo. Se han llevado a cabo estudios cinéticos de la oxidación, paso a paso, de RuII,II a RuIV,IV , y se han determinado las constantes de oxidación de segundo orden para los distintos procesos de oxidación. La capacidad del aqua dímero en la oxidación del agua a oxígeno molecular ha sido investigada en solución homogénea utilizando CeIV como oxidante. La evolución de oxígeno se ha demostrado por cromatografia de gases. Se ha obtenido una eficiencia del 73% y 18.6 ciclos catalíticos, cuando 1.83 x 10-6 moles de dímero se han mezclado con un exceso de 100 equivalentes de cerio. El dímero con dos aguas cataliza también la oxidación del agua de forma heterogénea, con el complejo adsorbido sobre una membrana de nafion, aunque la eficiencia es menor. Se ha propuesto un mecanismo intramolecular para la reacción de oxidación del agua. Consiste en la oxidación a 4 electrones del dímero, de RuII,II a RuIV,IV, el cual reacciona con el agua para formar oxígeno y revierte nuevamente al estado de oxidación II,II. Este modelo es consistente con estudios catalíticos de la evolución de oxígeno en función de las concentraciones de cerio y catalizador, llevados a cabo en solución ácida homogénea, que demuestran que la oxidación a 4 electrones del agua se encuentra catalizada por una sola molécula de complejo bajo concentraciones elevadas de cerio. La constante de pseudo-primer-orden para la evolución de oxígeno tiene un valor de 1.4 x 10-2 s-1, que es uno de los valores de constante más elevados obtenidos hasta la fecha. Desafortunadamente, el aqua dímero se desactiva durante el proceso de catálisis dando lugar a una especie naranja, la cual estamos actualmente tratando de caracterizar., Two new mononuclear Ru complexes with formula [RuCl2(Hbpp)(dmso)2], 2a and 2b, have been prepared from [RuCl2(dmso)4] and Hbpp (3,5-bis(2-pyridyl)pyrazole). The fact that only three (2a and the pair of enantiomers 2b) from the six possible stereoisomers are obtained from this reaction, has been rationalized in terms of structural and electronic factors, particularly the intramolecular hydrogen bond between the inner dmso and the aminic proton of Hbpp. 2a and 2b have been structurally, spectroscopically and electrochemically characterized. In acetonitrile basic media, 2a has proven to undergo linkage isomerization reactions of one dmso ligand when going from RuII to RuIII. The kinetic and thermodynamic constants for this process have been determined by means of cyclic voltammetry. Irradiation of either 2a or 2b with UV or sunlight provokes the replacement of one dmso by an acetonitrile molecule so that a new compound is formed, which has been characterized in solution by spectroscopic and electrochemical techniques. The fact that only one of the two dmso ligands is substituted, compared to related systems where two successive substitutions of dmso for MeCN take place, suggests that the inner dmso is much more stable due to the hydrogen bond with the aminic proton of Hbpp. 2a and 2b have proven to be active catalysts in the hydrogen transfer from 2-propanol to acetophenone, yielding 2-phenylethyl alcohol as the only product and 42.1% conversion (36.1 metal cycles) at 80 ºC for 2a, which is markedly more efficient than 2b.Two geometrical chloro isomers with formula out and in-[Ru(Hbpp)(trpy)(Cl)]+, 2a (out) and 2b (in), are obtained from the reaction of cis(out),cis-[RuCl2(Hbpp)(dmso)2] and trpy (2,2':6',2"-terpyridine). Better yields of these complexes can be obtained by a different route which uses [RuCl3(trpy)] and bpp-BOC as starting materials. These compounds have been isolated and characterized by means of structural, spectroscopic and electrochemical techniques. 2a and 2b have been used as starting materials for the synthesis of the analogous aqua (out and in-[Ru(Hbpp)(trpy)(H2O)]2+; 3a and 3b) and pyridine (out and in-[Ru(Hbpp)(trpy)(py)]2+; 4a and 4b) complexes, which have also been isolated and characterized. The acid-base properties of the aqua complexes, 3a and 3b, and the pyridyne complex 4a have been thoroughly investigated by cyclic voltammetry (Pourbaix diagram) and acid-base spectrophotometric titrations. Mathematical treatment of the experimental data thus obtained has allowed us to determine the pKa values for the different protonation equilibria of the complexes in oxidation states II and III. 3a has been shown to be a good catalyst in the electrochemical oxidation of benzyl alcohol, presumably to benzaldehyde. The second-order rate constant for the process has been determined as 17.1 M-1 s-1 by mathematical simulation. Two different synthetic routes have been used to prepare the chloro-bridge dimer [Ru2(Cl)(bpp)(trpy)2]2+, 1, in good yield. The acetato-bridge dimer [Ru2(O2CCH3)(bpp)(trpy)2]2+, 2, has been obtained from 1 and excess sodium acetate. The diaqua complex [Ru2(bpp)(trpy)2(OH2)2]3+, 3, has been prepared from either basic hydrolysis of 1 or acid hydrolysis of 2. These complexes have been characterized by means of structural, spectroscopic and electrochemical techniques. Long-standing solutions of the diaqua dimer 3 in acidic media have proven to be unstable to coordination of anions from the solution. Crystals of the trifluoroacetato-bridge dimer 4 have been obtained in acidic CF3COOH media after some days. The acid-base properties of the diaqua dimer 3 have been thoroughly investigated by cyclic voltammetric and bulk electrolysis experiments, and the corresponding Pourbaix diagram obtained. The pKa for the one-proton deprotonation of one aqua ligand has been determined by acid-base spectrophotometric titration as 6.7. This low pKa value is attributed to the formation of the highly stable (Ru2O2H3) entity. The UV-vis spectra for the different oxidation states of 3, from RuIIRuII to RuIIIRuIV, have been obtained by either chemical or electrochemical oxidation of the complex. UV-vis kinetic studies on the stepwise oxidation from RuII,II to RuIV,IV have been performed, and the individual second-order rate constants for the different oxidation processes determined. The capability of 3 in water oxidation to molecular dioxygen has been investigated in homogeneous solution using CeIV as oxidant. Oxygen evolution has been clearly demonstrated by gas chromatography. An efficiency of 73% and 18.6 metal cycles were obtained using 1.83 x 10-6 mols of dimer and 100-fold molar excess of cerium. This complex has also been shown to catalyze water oxidation in a heterogenous Nafion membrane, but the yields of O2 evolution are lower. An intramolecular pathway for the water oxidation process has been proposed. It involves the four-electron oxidation of the RuII,II dimer to the RuIV,IV complex that reverts to the RuII,II oxidation state upon releasing of molecular dioxygen. This model is consistent with kinetic studies on the evolution of oxygen as a function of catalyst and cerium concentrations, performed in homogeneous acidic solution, which show that the four-electron oxidation of water is catalyzed by one molecule of complex under large excesses of cerium. The pseudo-first-order rate constant for oxygen evolution has been calculated as 1.4 x 10-2 s-1, which is among the highest values reported up to date. Unfortunately, the diaqua dimer 3 is deactivated during the catalysis to yield an orange species which we are currently trying to characterize.