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Liquid crystals (LCs) have garnered significant attention for their unique optical and electrical properties, making them promising candidates in various technological applications such as smart displays, sensors, telecommunications, biomedicals or wearable electronics. In this study, we explore the potential of several highly emissive benzothioxanthene imide (BTI) derivatives as LC materials with a focus on their robustness and temperature-stable emission behavior. By tailoring the molecular structure of BTIs, we have accomplished exceptional emissive properties while maintaining the inherent advantages of LCs, such as their self-organizing ability and responsive nature. We describe the formation of enantiotropic liquid crystals whose mesomorphic properties dependent on the nature, length, and position of the side chain. Moreover, we have investigated the thermal stability of their emission spectra over a wide range of temperature, highlighting their potential use in demanding conditions where precise optical performances are critical. Our findings underscore the importance of molecular design in achieving highly emissive LC materials with enhanced robustness and temperature stability, opening new avenues for the use of BTI derivatives., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub, APC financiada por la UCM

The presence of pollutants in aquatic environments is causing severe health effects on both humans and animals. To address this issue, it has become crucial to develop more efficient and environmentally friendly photocatalysts for the removal of persistent pollutant mixtures from water. In this context, photocatalysts containing more than two bismuth-based materials have rarely been explored for water remediation. With this in mind, we propose an innovative ternary composite, BiOCl-1/Bi12O17Cl2/Bi2O3, as a potentially sustainable visible light-active photocatalyst. Firstly, bismuth oxychloride has been prepared in the presence of ionic liquid, leading to the formation of BiOCl-1 with highly reactive {110} facets. Subsequently, the construction of the ternary composite has been accomplished using a facile and soft hydrothermal approach. The as-prepared BiOCl-1/Bi12O17Cl2/Bi2O3 composite has been successfully used in degrading binary mixtures of contaminants (i.e. ciprofloxacin, methylparaben or methyl orange), achieving an improved visible-light photocatalytic activity compared to single BiOCl-1 and other previously reported bismuth-based photocatalysts. In addition, the photocatalytic mechanism and degradation pathways have been elucidated through scavenger and electrochemical experiments, as well as chromatography-mass spectrometry (LC-MS) analysis, respectively., Ministerio de Ciencia e Innovación (España), Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub, APC financiada por la UCM

In this study, we present a novel approach for the synthesis of covalent organic frameworks (COFs) that overcomes the common limitations of non-scalable solvothermal procedures. Our method allows for the room-temperature and scalable synthesis of a highly fluorinated DFTAPB-TFTA-COF, which exhibits intrinsic hydrophobicity. We used DFT-based calculations to elucidate the role of the fluorine atoms in enhancing the crystallinity of the material through corrugation effects, resulting in maximized interlayer interactions, as disclosed both from PXRD structural resolution and theoretical simulations. We further investigated the electrocatalytic properties of this material towards the oxygen reduction reaction (ORR). Our results show that the fluorinated COF produces hydrogen peroxide selectively with low overpotential (0.062 V) and high turnover frequency (0.0757 s-1 ) without the addition of any conductive additives. These values are among the best reported for non-pyrolyzed and metal-free electrocatalysts. Finally, we employed DFT-based calculations to analyse the reaction mechanism, highlighting the crucial role of the fluorine atom in the active site assembly. Our findings shed light on the potential of fluorinated COFs as promising electrocatalysts for the ORR, as well as their potential applications in other fields., Depto. de Química Inorgánica, Depto. de Química Orgánica, Fac. de Ciencias Químicas, TRUE, pub, Descuento UCM

This review explores the state‐of‐the‐art of thermoelectric materials, covering different crystalline structures and material families (e.g., chalcogenides, Zintl phases, skutterudites, clathrates, oxides, half‐Heusler, organic–inorganic composites, metal–organic frameworks, and silicides). It examines their corresponding thermoelectric properties while considering the synthesis methods employed, paying significant attention to those that particularly follow sustainable routes. Additionally, the work addresses current challenges in the field, such as enhancing stability at high temperatures and reducing manufacturing costs. The understanding gained in this field opens avenues for designing more efficient and sustainable devices to convert waste heat into electrical energy, thereby advancing cleaner technologies., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Producción Científica, Typified by LiTMP and TMPMgCl.LiCl, (TMP=2,2,6,6-tetramethylpiperidide), s-block metal amides have found widespread applications in arene deprotonative metalation. On the contrary, transition metal amides lack sufficient basicity to activate these substrates. Breaking new ground in this field, here we present the synthesis and full characterisation of earth-abundant transition metals M(TMP)2 (M=Fe, Co). Uncovering a new reactivity profile towards fluoroarenes, these amide complexes can promote direct M−H exchange processes regioselectively using one or two of their basic amide arms. Remarkably, even when using a perfluorinated substrate, selective C-H metalation occurs leaving C−F bonds intact. Their kinetic basicity can be boosted by LiCl or NBu4Cl additives which enables formation of kinetically activated ate species. Combining spectroscopic and structural studies with DFT calculations, mechanistic insights have been gained on how these low polarity metalation processes take place. M(TMP)2 can also be used to access ferrocene and cobaltocene by direct deprotonation of cyclopentadiene and undergo efficient CO2 insertion of both amide groups under mild reaction conditions., Swiss National Science Foundation (SNF) (projects numbers 206021_ 177033 and 188573), the University of Bern, the Irish Research Council (GOIPG/2021/88, M.M.), and the University of Valladolid (CONVREC-2021-221, M.N.P.-D.)

Iron-doped TiO2 catalysts with two different iron contents (0.7 and 3.5 wt.%) as well as the corresponding undoped system, prepared by a combined sol–gel/microemulsion method and calcined at 600 °C, have been examined with respect to their behaviour for photocatalytic degradation of aqueous phenol with H2O2 under solar light. The activity results are complemented with structural/morphological and electronic characterization analysis achieved by XRD, TEM, Raman, SBET, UV–vis DRS and XPS techniques. A detrimental effect of the presence of iron on the photoactivity is detected for the sample with 0.7 wt.% iron. In contrast, some activity enhancement is produced for the sample with highest iron loading. Such irregular catalytic behaviour with respect to iron loading is analyzed on the basis of the presence of additional catalytic contributions from new photoactive species. These are created as a consequence of surface modifications produced under reaction conditions related to the existence of phenomena of iron leaching from the catalysts. Differences in the specific nanostructure present in each case can also play a role on explaining the differences observed in the photoactivity. Finally, an analysis of the photoactivity as a function of the oxidizing agent employed, either H2O2 or oxygen from air, is also performed., Ministerio de Educación y Ciencia, CSIC, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

The association of the [Ln(hfac)3(H2O)2] metallic building blocks with the new ligand [1,1’-binaphthalene]-8,8’-diylbis(diphenylphosphine oxide) (L) led to the formation of three mononuclear complexes of formula [Ln(hfac)3(L)] (LnIII = Eu (1), Dy (2) and Yb (3)). The mononuclear character of the compounds is due to the bidentate coordination mode adopted by L to link the metal. L allows the observation of the characteristic visible 5D0  7FJ (J = 0-4) EuIII- and near infrared 2F5/2  2F7/2 YbIII- emissions while 2 is only weakly emissive due to the mismatch between the energy positions of the triplet excited state of the ligand and DyIII emissive state. The magnetic data reveal a field-induced Single-Molecule Magnet (SMM) behavior for 2 and 3 with an efficient suppression of the Quantum Tunneling of the Magnetization (QTM). The slow magnetic relaxation occurs through a Raman process while the Orbach contribution is discarded as confirmed by the correlation with the MJ states energy splitting provided by the luminescence spectrum of 3, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

A novel family of square-planar Pd(II) complexes based on isoquinoline-functionalised pyrazolate ligands [Pd(pzR(n,n)iq)2] (R(n,n) = C6H3(OCnH2n+1)2, n = 4, 6, 8, 10, 12, 14, 16, 18) has been synthesised and characterised. The new complexes show mesomorphic properties and exhibit columnar mesophases that are highly-stable in exceptionally wide temperature ranges of up to 345 °C. The formation of nanochannels in the fluid liquid crystal phases generates continuous pathways for one-dimensional proton conduction on the basis of C–H⋯N proton transfer. The complex with an intermediate chain length (n = 12) shows the highest proton conductivity of 1.34 × 10−4 S m−1 at 269 °C in the hexagonal columnar mesophase, and an activation energy of 0.84 eV. The influence of both the terminal alkyl chain length and the mesophase columnar organisation on the proton conduction mechanism is demonstrated. The series of Pd(II) complexes investigated in this work constitutes one of the first examples of proton-conducting metallomesogens with potential applications in PEM fuel cells., Ministerio de Economía y Competitividad, Programa de Financiación de Universidad Complutense de Madrid-Santander Universidades (Spain), Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

The use of liquid crystals for the fabrication of displays incorporated in technological devices (TVs, calculators, screens of eBook’s, tablets, watches) demonstrates the relevance that these materials have had in our way of living. However, society evolves, and improved devices are looked for as we create a more efficient and safe technology. In this context, metallomesogens can behave as multifunctional materials because they can combine the fluidic state of the mesophases with properties such as photo and electroluminescence, which offers new exciting possibilities in the field of optoelectronics, energy, environment, and even biomedicine. Herein, it has been established the role of the molecular geometry induced by the metal center in metallomesogens to achieve the self-assembly required in the liquid-crystalline mesophase. Likewise, the effect of the coordination environment in metallomesogens has been further analyzed because of its importance to induce mesomorphism. The structural analysis has been combined with an in-depth discussion of the properties of these materials, including their current and potential future applications. This review will provide a solid background to stimulate the development of novel and attractive metallomesogens that allow designing improved optoelectronic and microelectronic components. Additionally, nanoscience and nanotechnology could be used as a tool to approach the design of nanosystems based on luminescent metallomesogens for use in bioimaging or drug delivery., Associate Laboratory for Green Chemistry—LAQV, FCT/MCTES (Portugal), Projects UIDB/50006/2020, PROTEOMASS Scientific Society (Portugal), Proteomass 2020 funds, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

The amidinate anions have been widely used in the formation of dinuclear complexes with paddlewheel structure. The higher donor character of this type of ligands, compared to carboxylate ligands, increases the electronic density of the dimetallic units giving, in the case of ruthenium, stable complexes with a large variety of oxidation states containing Ru24+, Ru25+ and Ru26+ units. Even complexes with Ru22+, Ru23+ and Ru27+ cores have been detected in electrochemical measurements and isolated in some cases. The influence of formamidinate and benzamidinate ligands in the synthesis, characterization, properties and reactivity of metal-metal bonded diruthenium complexes with paddlewheel structure in several oxidation states is considered. A revision of the electronic and magnetic properties of diruthenium complexes and their relationship with the different electronic configurations found in this type of complexes is broadly documented. Additionally, the switching between oxidation states is considered through the discussion of the results obtained by electrochemical measurements. Finally, the most relevant applications of the amidinatodiruthenium complexes are also reviewed., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

This work reports the application of photocatalytic disinfection to the inactivation of Acanthamoeba trophozoites, a free-living pathogenic amoeba. Two types of photocatalytic reactors configurations have been used: i) a slurry reactor using suspended titanium dioxide (TiO2); and, ii) a fixed-bed reactor using immobilized TiO2 onto glass Raschig rings. The effect of the chemical composition of water has been analysed, comparing the efficiency of the process in deionized water (DW) and synthetic wastewater treatment plant effluent (SWTPE). The inactivation of Acanthamoeba spp. has been compared to that of Escherichia coli bacteria, being also analysed the concomitant inactivation of both microorganisms. Our results show that 99% of inactivation of E. coli and Acanthamoeba spp. can be achieved using photocatalysis in both reactor configurations, but interestingly, the kinetics of inactivation of both microorganisms together differs from that found with them separately. Particularly, E. coli seems to be more resistant to the inactivation in the presence of Acanthamoeba spp. which has been justified by the screen effect caused by the bigger size of Acanthamoeba spp. This observation is more pronounced in DW as the composition of the SWTPE prevent the microorganisms from suffering osmotic and/or mechanical stress and protect cellular structures to the attack of reactive oxygen species (ROS). On the other hand, the difference between the inactivation rate of E. coli and Acanthamoeba, points out the importance of the different inactivation mechanisms, suggesting that the entry of small TiO2 particles into the cytoplasm of the Acanthamoeba cells provokes the attack of inner structures and as a consequence a faster inactivation. This mechanism is not possible when the catalyst is immobilized leading to a higher cell resistance to inactivation and consequently lower efficiency of the disinfection process., Spanish State Research 536 Agency (AEI), Spanish Ministry of Economy and Competitiveness (MINECO), Comunidad de Madrid, Fundación Universitaria San Pablo CEU, Instituto de Salud Carlos III, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

New dicatenar isoquinoline-functionalized pyrazoles, [HpzR(n,n)iq] (R(n,n)=C6H3(OCnH2n+1)2; n=4, 6, 8, 10, 12, 14, 16, 18), have been strategically designed and synthesized to induce mesomorphic and luminescence properties into the corresponding bis(isoquinolinylpyrazolate)platinum(II) complexes [Pt(pzR(n,n)iq)2]. Thermal studies reveal that all platinum(II) compounds exhibit columnar mesophases over an exceptionally wide temperature range, above 300 °C in most cases. The photophysical behavior was also investigated in solution and in the solid state. As a consequence of the formation of Pt⋅⋅⋅Pt interactions, the weak greenish emission of the platinum derivatives turns bright orange in the mesophase. Additionally, the complexes are sensitive to a great variety of external inputs, such as temperature, mechanical grinding, pressure, solvents, and vapors. On this basis, they are used as dopant agents of a polyvinylpyrrolidone or poly(methyl methacrylate) polymer matrix to achieve stimuli-responsive thin films., Ministerio de Economía y Competitividad (Spain), project CTQ2011-25172, Universidad Complutense de Madrid (Spain), project GR3/14-910300, Programa de Financiación de Universidad Complutense de Madrid-Santander Universidades (Spain), Unidade de Ciências Biomoleculares Aplicadas-UCIBIO (Portugal), FCT/MEC (UID/Multi/04378/2013), cofinanciated by ERDF under the PT2020 Partnership Agreement, Scientific Society PROTEOMASS (Portugal), Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

The series of perovskite rare-earth (RE) doped cobaltites (RE)CoO3 (RE = La–Dy) was prepared by microwave-assisted synthesis. The crystal structure undergoes a change of symmetry depending on the size of the RE cation. LaCoO3 is rhombohedral, S.G. R3̅c (No. 167), while, for the rest of the RE series (Pr–Dy), the symmetry is orthorhombic, S.G. Pnma (No. 62). The crystal structure obtained by X-ray diffraction was confirmed by high-resolution transmission electron microscopy, which yielded a good match between experimental and simulated images. It is further shown that the well-known magnetism in LaCoO3, which involves a thermally induced Co3+ (d6) low spin to intermediate or high spin state transition, is strongly modified by the RE cation, and a rich variety of magnetic order has been detected across the series., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Several metal–organic frameworks of nickel(II) were obtained starting from the molecular complex 1, [Ni(OH2)4(4-pyc)2] (4-pyc = 4-pyridinecarboxylate or isonicotinate). By using different reaction conditions, two polymorphs of the anhydrous complex [Ni(4-pyc)2]n (2a and 2b) and the polynuclear compound [Ni5(OH2)3(4-pyc)10]n (3) were obtained in very high yield. All of the compounds were characterized by elemental analysis and spectroscopic data. The crystal structure determination of compounds 2b and 3 was also carried out. Structural and topological analysis of these new structural types and other related ones were performed. It was found that compounds 2a and 2b are a rare case of coordination framework isomers. Thermogravimetric studies indicate that compounds 2b and 3 lose the pore-allocated solvent molecules at moderate temperatures without any significant structural change, and at higher temperatures, compounds 1 and 3 are transformed into 2a. Textural parameters that characterize the microporous networks for 2b and 3 were obtained by nitrogen-adsorption measurements. For both samples, the micropore size distribution indicates cylindrical pores with diameters of 0.85 (2b) and 0.90 nm (3). The values of Brunauer–Emmett–Teller and Langmuir surface areas are 178 and 185 m2 g–1 for compound 2b, and 995 and 982 m2 g–1 for compound 3. Micropore volumes are 0.065 and 0.350 cm3 g–1 for 2b and 3, respectively. The magnetic properties of compounds 1, 2a, and 2b are consistent with the presence of zero-field splitting and a small antiferromagnetic coupling between the metal atoms. The magnetic properties of the pentanuclear compound 3 were analyzed by considering one monomer with zero-field splitting caused by axially distorted NiII octahedral compounds, and two dimeric fragments with magnetic interactions within each dimetallic unit., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

A one-dimensional coordination polymer [Ni(tp)(OH2)4] (1) (tp = –O2CC6H4CO2–; terephthalate) has been synthesized under environmentally friendly conditions. It has been characterized by elemental analysis, infrared spectroscopy, thermogravimetry, single-crystal and powder X-ray diffraction, and magnetic measurements. Compound 1 is a rare example of 1D polymeric NiII dicarboxylate that shows ferromagnetic interactions through hydrogen bonds. The zigzag arrangement of the NiII octahedral units connected by hydrogen bonds distinguishes compound 1 from other [Ni(dicarboxylate)(OH2)4] compounds, in which the interactions are antiferromagnetic., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Silver vanadates with light absorption properties in the visible region were successfully prepared by a low temperature pathway (not exceeding 110 °C) using an optimized microemulsion methodology. The resulting materials were evaluated as photocatalysts in Rhodamine B photodegradation and characterized before and after reaction. The silver vanadates displayed silver metallic nanoparticles decorating the surface. The as-prepared Ag3VO4 catalyst was the most active. Nevertheless, this silver vanadate suffered important changes during reaction. The initial structure evolves yielding a silver pyrovanadate, Ag4V2O7, with a concomitant increase of the number and size of the silver metallic nanoparticles. The synergy between these Ag0 particles and the photoactivity of the Ag4V2O7 phase seems responsible of the high photoactivity of this material., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Titanium reduced oxides TiO2–x occupy, since long time, a prominent place on the landscape of binary metal oxides because of their intriguing ability to form extended defects that affect both the formation of new superlattices and different electronic behaviours. Related to these features, a wide range of practical applications has been achieved. Moved by the conviction of the great potential of understanding the influence of the reactivity, compositional variations and size effects on their functional properties, the aim of this personal account is the optimization of a recently developed strategy for the stabilization of low n TinO2n–1 terms. In particular, we will focus on the Ti4O7 composition as well as the incorporation of transition metals, like Mn, in order to deal with new reduced Magnéli phases., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Hybrid photocatalysis/membrane processes constitute promising alternatives for water and wastewater treatment because they combine the efficiencies of filtration membranes technology and the oxidative effect of the photocatalytic process, increasing the lifetime of the membranes. The main challenge of these systems is the incorporation of the titanium dioxide (TiO2) catalyst without altering the filtration properties of the membrane and the photocatalytic activity of the catalyst. One way to achieve this goal is generating the TiO2 layer by direct anodization of titanium supports under controlled conditions to form titanium dioxide nanotubes (TiO2-NTs). This work reports the development of novel photocatalytic titanium membranes based on the formation of TiO2-NT arrays by anodization under both potentiostatic and galvanostatic conditions, and the scaling-up of the most promising systems to operational membrane photoreactors. The results demonstrated that the galvanostatic method displays more controlled tuneability to obtain NTs formation than the potentiostatic method on porous surfaces. However, despite the formation of TiO2-NTs structures, the observed photocatalytic activity is lower than that exhibited by TiO2 nanoparticles deposited directly on the membrane, although in this case the transmembrane pressure is significantly higher, and therefore the operational pumping costs are greater. Synergistic effects of photocatalysis and microfiltration are clearly demonstrated in the application of the hybrid system to the removal of bacteria for water disinfection processes, showing a significant improvement in the inactivation of E. coli bacteria in water with respect to the bare membrane., Spanish Ministry of Economy and Competitiveness (MINECO), Comunidad de Madrid, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

La-filled skutterudites LaxCo4Sb12 (x = 0.25 and 0.5) have been synthesized and sintered in one step under high-pressure conditions at 3.5 GPa in a piston-cylinder hydrostatic press. The structural properties of the reaction products were characterized by synchrotron X-ray powder diffraction, clearly showing an uneven filling factor of the skutterudite phases, confirmed by transmission electron microscopy. The non-homogeneous distribution of La filling atoms is adequate to produce a significant decrease in lattice thermal conductivity, mainly due to strain field scattering of high-energy phonons. Furthermore, the lanthanum filler primarily acts as an Einstein-like vibrational mode having a strong impact on the phonon scattering. Extra-low thermal conductivity values of 2.39 W m−1 K−1 and 1.30 W m−1 K−1 are measured for La0.25Co4Sb12 and La0.5Co4Sb12 nominal compositions at 780 K, respectively. Besides this, lanthanum atoms have contributed to increase the charge carrier concentration in the samples. In the case of La0.25Co4Sb12, there is an enhancement of the power factor and an improvement of the thermoelectric properties., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

The luminescence properties of Pt(II) compounds can be modulated by controlling the assembly of their molecules both in the solution and in the solid state. This fact constitutes a powerful tool for developing materials with stimuli-responsive luminescence properties. Herein, we describe the self-assembly behaviour of several series of Pt(II) metallomesogens in two different media upon controlled conditions. On the one hand, we explore the ability of several metal cations to induce the formation of Pt⋯Pt aggregates in solution, with the main goal of enhancing the phosphorescent emission of these compounds. On the other hand, since these compounds exhibit liquid crystalline mesophases and the temperature can control the aggregation, we have fabricated Pt(II) compound-doped polymer films and silicone membranes that show stimuli-responsive luminescent properties. In both cases, the interactions between the Pt(II) compounds and the metal cations, or the polymer matrices, play a key role in the aggregation-induced emission enhancement (AIEE) behaviour of the dyes. The effects of the alkyl chain length, the molecular asymmetry, and the nature of the ligands in the establishment of these interactions are also evaluated., Ministerio de Economía y Competitividad, MINECO/FEDER (Spain), project CTQ2015-63858-P, PROTEOMASS Scientific Society (Portugal), Associate Laboratory for Green Chemistry-LAQV/REQUIMTE, FCT/MEC (Portugal), project UID/QUI/50006/2013, Universidad Complutense de Madrid-Santander Universidades (Spain), Fundación Alfonso Martín Escudero (Spain), Ministerio de Economía y Competitividad (Spain) and European Social Fund - BES-2014-070964, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Contrary to molecular species, only very few solids are reported to host manganese (V) species. Herein, we report three new compounds with a hydroxyapatite structural backbone built on the MnVO4 3− anion: Sr5[(Mn1−xSix)O4]3(OH)1−3x (x = 0 and 0.053), Sr5(MnO4)3(OH)1−yFy (y = 0.90), and Sr5[(Mn1−xSix)- O4]3F1−3x (x = 0.058). These solids are fully characterized using powder X-ray and neutron powder diffraction, scanning transmission electron microscopy, electron energy loss spectroscopy (EELS), thermogravimetric analysis, and magnetic measurements. Especially, we report for the first time EELS Mn−L2,3 spectra of manganese with the oxidation state (V). Contrary to other Mn(V) oxides, these solids and the nominal compound Sr5(MnO4)3OH do not comprise Ba2+ cations but rely only on Sr2+ cations, showing that barium is not a required element to stabilize Mn(V) species in inorganic solids. We show that by tuning soft chemistry conditions on the one hand and post-treatment topological transformation conditions on the other hand, Mn(V) and hydroxyl groups can be substituted by Si(IV) and fluoride ions, respectively. Hence, we deliver solids with a potentially wide composition range. These compounds show significant oxygen anionic conduction, thus suggesting the emergence of new functional materials built from high-oxidation state manganese cations., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Skutterudite‐type pnictides based on CoSb3 are promising semiconductor materials for thermoelectric applications. An exhaustive structural characterization by synchrotron X‐ray powder diffraction of different M‐filled CoSb3 (M = Y, K, Sr, La, Ce, Yb) skutterudites, with a panoply of M atoms with very different chemical nature, allows to better understand the effects of filling from a crystallo‐chemical point of view. These analyses focus on the correlation of chemical and structural features with the enhanced thermoelectric properties displayed by certain families of filled‐CoSb3 skutterudites. These are mainly determined by Sb positional parameters, yielding Oftedal plots that depend on the filling fraction, ionic state, and atomic radius of the filler. Together with the distortion of [Sb4] rings and [CoSb6] octahedra present in the skutterudite structure, these results are linked to the band‐convergence concept and its influence on the thermoelectric transport properties. Here, the structural changes observed in the different chemical compositions are relevant to understand the improved thermoelectric performance of single partially filled n‐type skutterudites., Ministerio de Ciencia, Innovación y Universidades, MICINN, CAPES agency, Comunidad de Madrid y Universidad Complutense de Madrid (UCM), Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Five nickel complexes, [Ni2(3,4,5-tmb)4(4,4 ′-bpy)] (1), [Ni2(2-ntc)4(4,4 ′-bpy)] (2), [Ni(9-atc)2(4,4 ′-bpy)] (3), [Ni(3,4,5-tmb)2(t-bpee) ] (4), and [Ni2(2-ntc)4(t-bpee)2] (5) (3,4,5-tmb=3,4,5-trimethoxybenzoate; 2-ntc=2-naphthalenecarboxylate; 9-atc=9-anthracenecarboxylate; 4,4 ′-bpy=4,4 ′-bipyridine; t-bpee=trans-1,2-bis(4-pyridyl)ethylene), are prepared. They are characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and single-crystal and powder X-ray diffraction. 1 and 2 form linear chains of paddlewheel units joined by 4,4 ′-bpy ligands; 3 and 4 display zigzag chains formed by cis-bis(chelate) Ni(O2CR)2 units joined by 4,4 ′-bpy and t-bpee, respectively; and the structure of 5 consists of double chains. The magnetic behavior of the compounds is also studied, and DFT calculations using the broken-symmetry approximation are performed to gain a better understanding of the strong antiferromagnetism found in 1. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

The full rare-earth (RE) chromites series (RE)CrO3 with an orthorhombic distorted (Pnma) perovskite structure and the isostructural compound YCrO3 can be synthesized through a simple microwave-assisted technique, yielding high-quality materials. Magnetization measurements evidence that the Néel temperature for antiferromagnetic Cr3+–Cr3+ ordering strongly depends on the RE3+ ionic radius (IOR), and a rich variety of different magnetic spin interactions exists. Dielectric spectroscopy on sintered pellets indicates electronic inhomogeneity in all samples as manifested by the presence of at least two dielectric relaxation processes associated with grain boundary and grain interior bulk contributions. X-ray diffraction, Raman spectroscopy, and temperature-dependent dielectric permittivity data do not indicate potential noncentrosymmetry in the crystal or concomitant ferroelectricity. Strong correlations between the magnetic and dielectric properties were not encountered, and microwave-synthesized (RE)CrO3 may not be classified as magnetoelectric or multiferroic materials., Comunidad de Madrid, MICINN, MICINN, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Luminescent hollow micro- and nanocrystals have been successfully obtained taking advantage of the self-assembly behavior and the aggregation-induced emission enhancement properties of several bispyrazolate Pt(II) metallomesogens decorated with four terminal alkyl chains. Oil-in-water droplets have been used to confine the Pt(II) compounds and drive them to be self-assembled via intermolecular Pt···Pt interactions into spherical aggregates of about 200 or 50 nm. Evaporation of the oil phase generates highly-stable aqueous dispersions of nanocrystals that emit a bright orange light as a result of the existence of 3MMLCT excited states. Different methods and conditions have been tested for studying the effect of several parameters such as the temperature and the stirring speed in the final particle size and in the polydispersity index. Moreover, the micro- and nanocrystals are able to entrap hydrophobic drugs between the alkyl chains of the compounds, forming stable dispersions of drug-loaded capsules in water. The droplet method is applied in the area of metallomesogens for the first time to synthesize self-assembled Pt(II) nanocapsules, which opens a new field of study that could allow the use of these liquid crystal materials in biomedical applications., Associate Laboratory for Green Chemistry-LAQV, FCT/MCTES (Portugal), project UIDB/50006/2020), PROTEOMASS Scientific Society (Portugal), Fundación Alfonso Martín Escudero (España), Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Microwave and solvothermal activation processes have been explored as tools for the preparation of various nickel and ruthenium complexes. Different reaction conditions are tested using ethanol or water as solvents. Three nickel derivatives, [Ni(9-atc)2(OH2)2(py)2]·2EtOH (1), [Ni2(9-atc)4(OH2)(py)4]·2H2O (2·2H2O), and [Ni2(9-atc)4(py)2] (3), and two diruthenium compounds, {[Ru2Cl(9-atc)4]·2H2O}n (4) and [Ru2(9-atc)4(EtOH)2]·2EtOH (5), are obtained. The crystal structure determination of complexes 1-3 and 5 is also described. Compound 1 displays a 1D extended supramolecular structure with hydrogen bonds involving crystallization solvent molecules. Compound 2 is dimetallic, and both nickel centers show an octahedral coordination environment, whereas complexes 3 and 5 display a typical carboxylate-bridged paddlewheel-type structure with two metal atoms connected by four bridging carboxylate ligands. All compounds show weak antiferromagnetic interactions except 3, where a strong intra-dimer antiferromagnetic coupling is observed. Compound 4 also shows a strong zero field splitting., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

In this work, the sol–gel synthesis, structural characterization, and transport properties of a new solid solution of the general formula LaxBi1–xFe0.5Cr0.5O3 (0.4 ≤ x ≤ 1) are presented. The solubility limit x has been determined and variation of the lattice parameters measured through profile fitting. The cell parameters, space group, and atomic positions, as obtained by the Rietveld refinement of X-ray diffraction data, are reported. This analysis and electron diffraction studies as well do not reveal any evidence of Fe/Cr ordering. Regarding the transport properties, magnetic and electric characterizations are described. The electrical response with the temperature and frequency has been studied, and a “positive temperature coefficient” for the resistivity has been found for temperatures between 270 and 400 °C. The magnetic behavior is striking because, for all materials studied, zero-field-cooling curves appear above field-cooling ones, an anomalous feature that is interpreted as being due to complex ferromagnetic/antiferromagnetic interactions in the B perovskite sublattice., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Porous silica materials make great supports for heterogeneous catalysis with immobilized enzymes; however, direct functionalization of their surface through stable attachment of enzymes, reporter molecules, or both is a difficult problem. Overcoming that is necessary for practical implementation. Here, we integrate the development of luminophor-doped oxygen-sensing silica materials with a modular strategy of enzyme immobilization to demonstrate generally applicable design of an oxygen-dependent biocatalyst on a porous silica support. Zbasic2, a highly positively charged silica-binding module of about 7 kDa size, was fused to d-amino acid oxidase, and the resulting chimeric protein was tethered noncovalently via Zbasic2 in defined orientation and in a highly selective manner on silica. The enzyme supports used differed in overall shape and size as well as in internal pore structure. A confocal laser scanning microscopy (CLSM) analysis that employed the oxidase’s flavin cofactor as the fluorescent reporter group showed a homogeneous internal protein distribution in all supports used. Ru-based organometallic luminophor was adsorbed tightly onto the silica supports, thus enabling internal optical sensing of the O2 available to the enzymatic reaction. Optimization of the surface labeling regarding homogeneous luminophor distribution was guided, and its efficacy was verified by CLSM. Mesostructured silica surpassed controlled pore glass by ≥10-fold in terms of immobilized enzyme effectiveness at high loading of oxidase activity. The effect was shown from detailed comparison of the time-resolved O2 concentration profiles in solution and inside porous support to result exclusively from variable degrees of diffusion-caused limitation in the internal O2 availability. Enzyme immobilized on mesostructured silica approached perfection of a heterogeneous biocatalyst in being almost as effective as the free enzyme (assayed in oxidative deamination of d-methionine), thus emphasizin, Depto. de Ingeniería Química y de Materiales, Fac. de Ciencias Químicas, TRUE, pub

A series of Ni/Fe electrodes have been prepared by electrodeposition of metal salt precursors on different substrates. The surface morphology, chemical composition and electrochemical characteristics of these electrodes were studied by various physico-chemical techniques such as X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM). The electrochemical properties of the electrodes were examined by steady-state polarization curves. First, the influence of features such as Ni/Fe composition and type of substrate for the oxygen evolution reaction (OER) were determined by electrochemical techniques in a conventional 3-electrodes cell. The overpotential for the OER is lower for the electrodes with the higher concentrations of Ni. The electrodes with a Ni/Fe composition of 75/25 wt.% electrodeposited on steel mesh and/or 75/25 and 50/50 wt.% on nickel foam result in the most active configurations for the OER. These electrodes were further tested as anodes for alkaline water electrolysis during at least 70 h. In order to understand their activity and stability, the used electrodes were also characterized by SEM and compared to the fresh electrodes. Among the compositions and substrates examined, the Ni50Fe50-Nf electrode exhibited the lowest overpotential (2.1 V) for the OER and the higher stability as anode in an alkaline water electrolysis cell., Spanish Education and Science Ministry, CENIT-SPHERA, MICINN, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Acuerdo transformativo, Despite the large number of synthesis methodologies described for superparamagnetic iron oxide nanoparticles (SPIONs), the search for their large-scale production for their widespread use in biomedical applications remains a mayor challenge. Flame Spray Pyrolysis (FSP) could be the solution to solve this limitation, since it allows the fabrication of metal oxide nanoparticles with high production yield and low manufacture costs. However, to our knowledge, to date such fabrication method has not been upgraded for biomedical purposes. Herein, SPIONs, European Union, Ministerio de Ciencia e Innovacion de España, Depto. de Química en Ciencias Farmacéuticas, Fac. de Farmacia, TRUE, pub

Three coumarin-based boron complexes (L1, L2 and L3) were designed and successfully incorporated into polymeric matrixes for evaluation as temperature probes. The photophysical properties of the complexes were carried out in different solvents and in the solid state. In solution, compound L1 exhibited the highest fluorescence quantum yield, 33%, with a positive solvatochromism also being observed on the absorption and emission when the polarity of the solvent increased. Additionally in the presence of anions, L1 showed a colour change from yellow to pink, followed by a quenching in the emission intensity, which is due to deprotonation with the formation of a quinone base. Absorption and fluorescence spectra of L1 were calculated at different temperatures by the DFT/B3LYP method. The decrease in fluorescence of compound L1 with an increase in temperature seems to be due to the presence of pronounced torsional vibrations of the donor and acceptor fragments relative to the single bond with C(carbonyl)-C (styrene fragment). L1, L2 and L3, through their incorporation into the polymeric matrixes, became highly emissive by aggregation. These dye@doped polymers were evaluated as temperature sensors, showing an excellent fluorescent response and reversibility after 15 cycles of heating and cooling., Universidade Nova de Lisboa, Portuguese government, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Surface microbial colonization and its potential biofilm formation are currently a major unsolved problem, causing almost 75% of human infectious diseases. Pathogenic biofilms are capable of surviving high antibiotic doses, resulting in inefficient treatments and, subsequently, raised infection prevalence rates. Antibacterial coatings have become a promising strategy against the biofilm formation in biomedical devices due to their biocidal activity without compromising the bulk material. Here, we propose for the first time a silver-based metal–organic framework (MOF; here denoted AgBDC) showing original antifouling properties able to suppress not only the initial bacterial adhesion, but also the potential surface contamination. Firstly, the AgBDC stability (colloidal, structural and chemical) was confirmed under bacteria culture conditions by using agar diffusion and colony counting assays, evidencing its biocide effect against the challenging E. coli, one of the main representative indicators of Gram-negative resistance bacteria. Then, this material was shaped as homogeneous spin-coated AgBDC thin film, investigating its antifouling and biocide features using a combination of complementary procedures such as colony counting, optical density or confocal scanning microscopy, which allowed to visualize for the first time the biofilm impact generated by MOFs via a specific fluorochrome, calcofluor., Comunidad de Madrid, European Regional Development Fund, European Union’s Horizon 2020, European Research Council (Advanced Grant VERDI; ERC-2015-AdG Proposal No 694160), Depto. de Química en Ciencias Farmacéuticas, Fac. de Farmacia, TRUE, pub

The production of cooked ham has been gaining popularity in recent years in Spain. In general, the production process carried out by the companies remains traditional, and different production methods are therefore being sought to innovate and improve the quality of the product. This is either through pig crossbreeding, varying additives and ingredients, improving some stages of the production process, or providing nutritional and health claims that are useful to guiding the purchasing decision of consumers. Obviously, this series of changes must be subject to Spanish and European regulations in order to be marketed inside and outside the country, Universidad Complutense de Madrid, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

A crucial challenge to face in the treatment of biofilm-associated infection is the ability of bacteria to develop resistance to traditional antimicrobial therapies based on the administration of antibiotics alone. This study aims to apply magnetic hyperthermia together with controlled antibiotic delivery from a unique magnetic-responsive nanocarrier for a combination therapy against biofilm. The design of the nanosystem is based on antibiotic-loaded mesoporous silica nanoparticles (MSNs) externally functionalized with a thermo-responsive polymer capping layer, and decorated in the outermost surface with superparamagnetic iron oxide nanoparticles (SPIONs). The SPIONs are able to generate heat upon application of an alternating magnetic field (AMF), reaching the temperature needed to induce a change in the polymer conformation from linear to globular, therefore triggering pore uncapping and the antibiotic cargo release. The microbiological assays indicated that exposure of E. coli biofilms to 200 µg/mL of the nanosystem and the application of an AMF (202 kHz, 30 mT) decreased the number of viable bacteria by 4 log10 units compared with the control. The results of the present study show that combined hyperthermia and antibiotic treatment is a promising approach for the effective management of biofilm-associated infections., Horizon 2020, European Research Council, Ministerio de Ciencia e Innovación, Depto. de Química en Ciencias Farmacéuticas, Fac. de Farmacia, TRUE, pub

The paddlewheel [Ru2Cl(O2CCH3)4] complex was previously reported to react with the model protein hen egg white lysozyme (HEWL), forming adducts with two diruthenium moieties bound to Asp101 and Asp119 side chains upon the release of one acetate. To study the effect of the equatorial ligands on the reactivity with proteins of diruthenium compounds, X-ray structures of the adducts formed when HEWL reacts with [Ru2Cl(D-p-FPhF)(O2CCH3)3] [D-p-FPhF = N,N′-bis(4-fluorophenyl)formamidinate] under different conditions were solved. [Ru2Cl(D-p-FPhF)(O2CCH3)3] is bonded through their equatorial positions to the Asp side chains. Protein binding occurs cis or trans to D-p-FPhF. Lys or Arg side chains or even main-chain carbonyl groups can coordinate to the diruthenium core at the axial site. Data help to understand the reactivity of paddlewheel diruthenium complexes with proteins, providing useful information for the design of new artificial diruthenium-containing metalloenzymes with potential applications in the fields of catalysis, biomedicine, and biotechnology., Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Producción Científica, Glucose oxidase (GOX) and catalase (CAT) were co-immobilized in silica–calcium–alginate hydrogels to degrade must glucose. The effect of the enzyme dose (1.2–2.4 U/mL), the initial must pH (3.6–4.0), and the incubation temperature (10–20 °C) on the glucose consumption, gluconic acid concentration, pH, and color intensity of Verdejo must was studied by using a Box–Behnken experimental design and comparing free and co-immobilized enzymes. A reduction of up to 37.3 g/L of glucose was observed in co-immobilized enzyme-treated must, corresponding to a decrease in its potential alcohol strength of 2.0% vol. (v/v), while achieving a slight decrease in its pH (between 0.28 and 0.60). This slight acidification was due to a significant reduction in the estimated gluconic acid found in the must (up to 73.7%), likely due to its accumulation inside the capsules. Regarding the operational stability of immobilized enzymes, a gradual reduction in glucose consumption was observed over eight consecutive cycles. Finally, co-immobilized enzymes showed enhanced efficiency over a reaction period of 48 h, with an 87.1% higher ratio of glucose consumed per enzyme dose in the second 24 h period compared with free enzymes. These findings provide valuable insights into the performance of GOX–CAT co-immobilized to produce reduced-alcohol wines, mitigating excessive must acidification.

Producción Científica, Low-dimensional materials have experienced a real revolution in both the technological and research fields in recent decades. Their unique properties have opened up a new frontier in the pursuit of novel technological advancements. By confining matter to reduced dimensions, such as thin layers or even individual atomic planes, low-dimensional materials are able to exhibit remarkable physical, chemical, and electronic properties that differ significantly from their bulk counterparts. This allows for the tailoring and engineering of their properties by simply controlling their geometrical parameters. [Texto extraído del artículo de Jesús Martínez Puras].

Producción Científica, Low-dimensional materials have been revolutionary in both the technological and research fields over the last decades. Since the discovery of graphene in 2004, and thanks to the technological improvements in nanotechnology achieved during this last century, the number of low-dimensional materials under research and their potential applications have not stopped increasing. In this review, we present a comprehensive tour of the principal 2D and 1D materials that compose the current state of the art and also the technological applications derived from them. In both cases, the focus will be on their optical and electrical properties, as well as the potential applications on novel photonic, electronic, or optoelectronic devices. For 2D materials, we will focus on a brief review of graphene-like materials, giving more emphasis to graphene derivatives, hexagonal boron nitride, and transition metal dichalcogenides. Regarding 1D materials, we will aim at metallic and semiconductor nanowires. Nevertheless, interesting 2D and 1D materials are mentioned in each section. The topic will be introduced using the related origin of their unique capabilities as a common thread. At the same time, we will try to remark on the differences and similarities between both groups and their physical relationship., Unión Europea–NextGenerationEU y Universidad de Valladolid, Ayudas Margarita Salas - (grant CONVREC-2021-23)

Producción Científica, More than 260 million surgical procedures are performed worldwide each year. Although sutures and staples are widely used to reconnect tissues, they can cause further damage and increase the risk of infection. Bioadhesives have been proposed as an alternative to reconnect tissues. However, clinical adhesives that combine strong adhesion with cytocompatibility have yet to be developed. In this study, we explored the production of adhesives based on protein-engineered polymers bioinspired by the sequence of elastin (i.e., elastin-like recombinamers, ELRs). We hypothesized that the combination of polyphenols (i.e., tannic acid, TA) and ELRs would produce an adhesive coacervate (ELR+TA), as reported for other protein polymers such as silk fibroin (SF). Notably, the adhesion of ELR alone surpassed that of ELR+TA. Indeed, ELR alone achieved adhesive strengths of 88.8 ± 33.2 kPa and 17.0 ± 2.0 kPa on porcine bone and skin tissues, respectively. This surprising result led us to explore a multicomponent bioadhesive to encompass the complementary roles of elastin (mimicked here by ELR) and silk fibroin (SF), and subsequently mirror more closely the multicomponent nature of the extracellular matrix. Tensile testing showed that ELR+SF achieved an adhesive strength of 123.3 ± 60.2 kPa on porcine bone and excellent cytocompatibility. To express this in a more visual and intuitive way, a small surface of only 2.5 cm2 was able to lift at least 2 kg of weight. This opens the door for further studies focusing on the ability of protein-engineered polymers to adhere to biological tissues without further chemical modification for applications in tissue engineering., Gobiernos federal y estatal de Alemania - (StUpPD370-20), Ministerio Alemán de Educación e Investigación (BMBF) - (grant 13XP5136), Gobierno de España - (grant PID2019- 110709RB-100, RED2018-102417-T), Junta de Castilla y León - (grant VA317P18, Infrared2018-UVA06), Programa de Cooperación Interreg España-Portugal POCTEP - (grant 0624_2IQBIONEURO_6_E)

Producción Científica, A new approach to produce porous membranes with dense or porous top layer is proposed in this work by employing a solvent-free method. PMMA/MAM formulations were selected as a base material in order to create open-cell or close-cell structures by gas dissolution foaming employing CO2 as a blowing agent. Furthermore, by introducing the gas diffusion barrier approach to CO2 dissolution foaming, it is possible to control the thickness of the dense layer in both edges, obtaining defect-free membranes (i.e., completely dense without pin-holes). The effectiveness of nanocellular polymers as gas separation membranes was evaluated. In this way, the permeability, selectivity, and permeance were correlated to the cellular structure (open or close-cell) as well as to the dense layer thickness. Furthermore, the effective thickness of the selective layer has been calculated from gas permeability measurements, obtaining an accurate control of that parameter from the tunable cellular structure. Therefore, membranes composed of desired selective layer and a porous structure as a mechanical support are produced by a solvent-free methodology., Ministerio de Ciencia e Innovación (PRE2019-088820), EU NextGenerationEU/ PRTR program (PLEC2021-007705), FEDER (UE) (RTI2018 - 098749-B-I00, RTI2018 - 097367-A-I00, PID2021-127108OB-I00, PID2019-109403RB-C21/AEI/10.13039/501100011033, TED2021-13 0965B-I00 y PDC2022-133391- I00), Junta de Castilla y León and EU-FEDER program (CLU-2019-04 and VA202P20)

New insights into the chemical and structural features of iron or titanium-doped KxMnO2 hollandites are reported. Neutron diffraction and atomically resolved transmission electron microscopy elucidate the localization of the dopant cations that could be one of the key factors governing the functional activity of these nanomaterials, Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

The work developed in this Thesis entails the design and synthesis of new phosphine ligands. These phosphines show either a 2-chalcone or a 2-biaryl moiety, where their fluorination degree modulates their electronic properties. The new ligands have been employed in different systems in combination with transition metals in order to study different topics such as metal-ligand interactions, reaction mechanism, catalysis or luminescent properties. The 2-chalcone phosphines (PEWO) have been identified as excellent promoters of the reductive elimination step both with Ni and Pd. This ability has been exploited to develop a Negishi catalysis to synthetize symmetric and non-symmetric highly fluorinated biaryls under mild conditions with excellent yields and great selectivity. The selectivity of this process can be further enhanced by means of a bimetallic Pd/Cu system, due to the in situ generation of the nucleophile in catalytic concentrations. The development of these two catalytic systems encouraged us to design new Pd complexes with partially fluorinated aryls that could act as efficient precatalysts with easy activation. PEWO ligands, as well as some of their Pd complexes, also exhibit luminescent properties due to the fluorinated 2-chalcone moiety they have in their structure. 2-biarylphosphines have been employed to analyze the metal-ligand interaction in [AuCl(L)] complexes in combined experimental and computational studies. These phosphines also show a peculiar cyclization reaction that implies an intramolecular SNAr reaction between the P atom and the ortho C–F bond of the lower aryl, leading to luminescent fluorophosphoranes., El trabajo desarrollado en esta Tesis implica el diseño y síntesis de nuevos ligandos fosfina. Estas fosfinas presentan un grupo 2-chalcona o 2-biarilo en su estructura, donde su grado de fluoración modula sus propiedades electrónicas. Los nuevos ligandos han sido empleados en distintos sistemas en combinación con metales de transición para abordar diversas temáticas como las interacciones metal-ligando, mecanismos de reacción, catálisis o propiedades luminiscentes. Las fosfinas derivadas de 2-chalcona (PEWO) han sido identificadas como excelentes promotores de la etapa de eliminación reductora tanto en Ni como en Pd. Esta habilidad ha sido explotada para desarrollar una catálisis de tipo Negishi para la síntesis de biarilos altamente fluorados tanto simétricos como asimétricos en condiciones de reacción suaves, con rendimientos excelentes y alta selectividad. La selectividad de este proceso puede ser incrementada aún más mediante un sistema bimetálico Pd/Cu, gracias a la generación in situ del nucleófilo en concentraciones catalíticas. El desarrollo de estos dos sistemas catalíticos nos animó a diseñar nuevos complejos de Pd con arilos parcialmente fluorados que actuasen como precatalizadores de activación fácil altamente eficientes. Los ligandos PEWO, al igual que alguno de sus complejos de Pd, también presentan propiedades luminiscentes debido a la presencia del grupo 2-chalcona fluorado en su estructura. Las fosfinas 2-biarílicas han sido utilizadas para analizar las interacciones metal-ligando en complejos [AuCl(L)] mediante la combinación de estudios experimentales y teóricos. Estas fosfinas también presentan una peculiar reacción de ciclación que implica una reacción SNAr intramolecular entre el átomo de fósforo y el enlace C–F en posición orto del arilo inferior, generando fluorofosforanos luminiscentes., Escuela de Doctorado, Doctorado en Química: Química de Síntesis, Catálisis y Materiales Avanzados

The doctoral thesis focuses on the design and study of catalytic systems for the formation of C-C bonds using copper catalysis. Additionally, multimetallic systems using other metals of the first raw, such as iron, or more traditional systems such as Pd/Cu, or the use of photochemical methodologies for the formation of reactive molecules are employed. On the other hand, mechanistic studies of these catalytic systems and derivatives are carried out in order to elucidate the reaction mechanism . For this purpose, techniques based on nuclear magnetic resonance (NMR) and computational support are used., La tesis se enfoca en el diseño y estudio de sistemas catalíticos para la formación de enlaces C-C empleando catálisis de cobre. Adicionalmente, se emplean sistemas multimetálicos empleando otros metales de la primera serie de transición, como el hierro, sistemas más tradicionales como Pd/Cu, o el empleo de metodologías fotoquímicas para la formación de moléculas reactivas. Por otro lado, se realizan estudios mecanísticos de dichos sistemas catalíticos y derivados, con la finalidad de elucidar el mecanismo de reacción de forma inequívoca. Para ello, se emplean técnicas basadas en resonancia magnética nuclear (RMN) y apoyo computacional., Escuela de Doctorado, Doctorado en Química: Química de Síntesis, Catálisis y Materiales Avanzados

One of the main goals of research in Chemistry nowadays is to achieve more efficient chemical syntheses. The work in this thesis is intended to contribute to this goal by improving the efficiency of palladium catalyzed processes. With this aim, the research is focused on the use of novel catalysts in combination with mechanistic studies of the steps that constitute the catalytic cycles. Two different types of catalytic processes were chosen: cross-coupling reactions of arenes that involve C-H activation, and cross-coupling processes that use carbene precursors. Both are attractive reactions to achieve molecular complexity in a reduced number of synthetic steps: The first one because no prefunctionalization of the arenes, the available raw materials, is needed; the second one because the formation of more than one C-C or C-X bonds occurs in just one synthetic step. The analysis of catalytic and stoichiometric reactions, Uno de los principales objetivos en Química es conseguir procesos sintéticos mucho más eficientes. Es por ello que, el trabajo contenido en la presente tesis trata de contribuir a este fin mediante la mejora en la eficiencia de los procesos catalizados por paladio. Con este propósito, mi investigación se ha centrado en desarrollar nuevos catalizadores en combinación con estudios mecanísticos de las etapas que constituyen los ciclos catalíticos. Se han elegido dos tipos de procesos catalíticos de acoplamiento cruzado C-C: El primero de ellos involucra etapas de activación C-H de arenos y el segundo proceso involucra precursores de carbeno y especies carbénicas de paladio. Ambos procesos son interesantes para conseguir complejidad molecular en el menor número de etapas sintéticas. En el primer proceso no se requieren reactivos que hayan sido previamente funcionalizados, empleando de esta manera, las materias primas directamente (hidrocarburos). En el segundo proceso estudiado se puede llevar a cabo la formación de más de un enlace C-C o C-X (X = heteroátomo) en un solo paso de síntesis. El estudio de reacciones catalíticas y estequiométricas junto con estudios cinéticos y computacionales nos ha permitido conseguir información acerca de aspectos mecanísticos de las reacciones y de esta manera aportar un mejor entendimiento de los sistemas catalíticos comentados anteriormente., Escuela de Doctorado, Doctorado en Química: Química de Síntesis, Catálisis y Materiales Avanzados

RESEARCHER ID M-3378-2014 (María Vallet Regí) ORCID 0000-0002-6104-4889 (María Vallet Regí) RESEARCHER ID N-4501-2014 (Sandra Sánchez Salcedo) ORCID 0000-0002-1889-2057 (Sandra Sánchez Salcedo), In the present study, the effects of nanocrystalline hydroxyapatite (nano-HA) and nanocrystalline Si-substituted hydroxyapatite (nano-SiHA) on osteoclast differentiation and resorptive activity have been evaluated in vitro using osteoclast-like cells. The action of these materials on proinflammatory and reparative macrophage populations was also studied. Nano-SiHA disks delayed the osteoclast differentiation and decreased the resorptive activity of these cells on their surface, as compared to nano-HA samples, without affecting cell viability. Powdered nano-SiHA also induced an increase of the reparative macrophage population. These results along with the beneficial effects on osteoblasts previously observed with powdered nano-SiHA suggest the potential of this biomaterial for modulating the fundamental processes of bone formation and turnover, preventing bone resorption and enhancing bone formation at implantation sites in treatment of osteoporotic bone and in bone repair and regeneration., Comunidad de Madrid, Ministerio de Ciencia e Innovacion (MICINN), Agening Network of Excellence, Depto. de Química en Ciencias Farmacéuticas, Fac. de Farmacia, TRUE, pub

RESEARCHER ID M-3378-2014 (María Vallet Regí) ORCID 0000-0002-6104-4889 (María Vallet Regí), Bioceramics for bone tissue regeneration, local drug delivery and nanomedicine, are receiving growing attention by the biomaterials scientific community. The design of bioceramics with improved surface properties able to overcome clinical issues is a great scientific challenge. Zwitterionization of surfaces has arisen as a powerful alternative in the design of biocompatible bioceramics capable to inhibit bacterial and non-specific protein adsorption, which opens up new insights into the biomedical applications of these materials. This manuscript reviews the different approaches reported up to date for the synthesis and characterization of zwitterionic bioceramics with potential clinical applications. Statement of Significance Zwitterionic bioceramics are receiving growing attention by the biomaterials scientific community due to their great potential in bone tissue regeneration, local drug delivery and nanomedicines. Herein, the different strategies developed so far to synthesize and characterize zwitterionic bioceramics with potential clinical applications are summarized. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved., Ministerio de Economía y Competitividad (MINECO), Agening Network of Excellence, Depto. de Química en Ciencias Farmacéuticas, Fac. de Farmacia, TRUE, pub

RESEARCHER ID M-3378-2014 (María Vallet Regí) ORCID 0000-0002-6104-4889 (María Vallet Regí) RESEARCHER ID K-3719-2014 (Miguel Manzano García) RESEARCHER ID M-3378-2014 (Miguel Manzano García) ORCID 0000-0001-6238-6111 (Miguel Manzano García) RESEARCHER ID S-2443-2016 (Miguel Gisbert Garzarán) ORCID 0000-0001-9815-0354 (Miguel Gisbert Garzarán), The application of nanotechnology to medicine constitutes a major field of research nowadays. In particular, the use of mesoporous silica and carbon nanoparticles has attracted the attention of numerous researchers due to their unique properties, especially when applied to cancer treatment. Many strategies based on stimuli-responsive nanocarriers have been developed to control the drug release and avoid premature release. Here, we focus on the use of the subtle changes of pH between healthy and diseased areas along the body to trigger the release of the cargo. In this review, different approximations of pH-responsive systems are considered: those based on the use of the host-guest interactions between the nanocarriers and the drugs, those based on the hydrolysis of acid-labile bonds and those based on supramolecular structures acting as pore capping agents., Unión Europea. H2020, European Research Council, Depto. de Química en Ciencias Farmacéuticas, Fac. de Farmacia, TRUE, pub