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Monomeric and dimeric NHP complexes were prepared by reaction of N-heterocyclic diphospholene with Fe, Co and Ni carbonyls.

The new ligand 8,10-di-tert-butylbenzo[b][1,10]phenanthrolin-11-ol and its lanthanide complexes were obtained and their photoluminescence and electrochemical properties were studied.

The heteroligand complexes CpLn(BQ)2(DME) (BQ = 10-oxybenzo[h]quinoline, Cp = cyclopentadienyl, Ln = La (1), Nd (2), Sm (3), Gd (4)) were synthesised by the reaction of Cp3Ln with (BQ)H. The complexes of La, Nd and Sm were structurally characterised. In the case of ytterbium the reaction affords Cp2Yb(BQ)(DME) (5) and homoligand binuclear complex Yb2(BQ)6 (6) iregardless of the molar ratio of initial reagents. Upon UV excitation all the complexes gave rise to fluorescence of ligands in the visible region. The photoluminescent spectrum of compound 1 also contains a phosphorescent band with a lifetime longer than 10 ms. The complexes of Nd, Sm and Yb along with ligand emission display metal-centered luminescent f–f transitions.

A set of novel ditopic 2-mercaptothiazoles has been synthesized. Depending on the nature of the bisthiazoles their sodium salts can form coordination compounds or 2D polymers.

The tandem isomerization and trifluoromethylation reactions are a simple, convenient, and atom-economical strategy for the synthesis of various products in high yields from simple substrates.

The reactions of monomeric [(dpp-Bian)M(thf)4] (M = Ca (1a), Sr (1b); dpp-Bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with 4,4'-bipyridyl (4,4'-bipy) proceed with electron transfer from dpp-Bian2- to 4,4'-bipy0 to afford calcium and strontium complexes containing simultaneously radical-anionic dpp-Bian- and 4,4'-bipy- ligands. In tetrahydrofuran (thf) the reactions result in 1D coordination polymers [{(dpp-Bian)M(4,4'-bipy)(thf)2}·4thf]n (M = Ca (2a), Sr (2b)), while in a thf/benzene mixture the reaction between 1a and 4,4'-bipy affords the 2D metal-organic framework [{(dpp-Bian)Ca(4,4'-bipy)2}·2thf·2C6H6]n (3). The structures of compounds 2a,b and 3 have been determined by single-crystal X-ray analyses. The presence of the ligand-localized unpaired electrons allows the use of ESR spectroscopy for characterization of the compounds 2a,b and 3. DFT calculations of model calcium complexes with the dpp-Bian, 4,4'-bipy, and thf ligands confirm the energetically favorable open-shell configurations of the molecules bearing the 4,4'-bipy fragments. The magnetic susceptibility measurements confirm the presence of two unpaired electrons per monomeric unit in 2a,b and 3. The thermal stability of compounds 2a,b and 3 was studied by thermogravimetric analysis (TGA). To the best of our knowledge, 3 is the first MOF simultaneously containing two different paramagnetic bridging ligands inside the framework.

Treatment of 3a,6a-diaza-1,4-diphosphapentalene (DDP) with an excess of PhBCl2 yields the corresponding bis(borane) adduct DDP(PhBCl2)2 (14), demonstrating the availability of two lone pairs on the phosphorus center. The reaction between DDP and B(C6F5)3 yields (1 : 1) phosphino-borane complex 16. The free lone electron pair on the pyramidal P atom in 16 participates in the intramolecular non-covalent interactions P(1)⋯F(1) and P(1)⋯F(6) giving additional 3.9 and 2.8 kcal mol−1, respectively, for stabilization of the complex. This through-space interaction appears in the 31P NMR spectrum as large spin–spin coupling constants of 271 and 219 Hz. The addition of water to 16 (1 : 1) leads to the formation of the insertion product 17 having –H2P–O–B(C6F5)3 moiety. The reaction of DDP with BH3·SMe2 proceeds in several stages, which include the insertion of the masked phosphinidene into the B–H and P–H bonds of the intermediate compounds followed by the dehydrocoupling step and formation of diphosphine 18. The last compound exists in solution as a set of stereoisomers.

It was found that the dicarbonyl-rhodium-o-semiquinonate complex (which thread-like crystals can bend reversibly under light/warm activation) can form two polymorphic modifications: isometric prisms (1) and sticks (2). Some thin sticks can bend as mentioned above. X-ray diffraction studies of polymorphic modifications at different temperatures were carried out. It was found that crystals 1 are destructed after cooling to 110 K as opposed to crystals 2. In turn, the reversible phase transition is detected in 2. In both polymorphic modifications, stack packaging motifs through the direct Rh-Rh bond are observed. The principal difference between packages of polymorphic modifications is that molecules 1 in the adjacent stacks are shifted relative to each other along the stack, in contrast to crystal 2. It was found that different packing of stacks leads to different anisotropic compression of crystals 1 and 2 during cooling, which is a key factor of their stability. Using the molecular invariom approach, the nature of the chemical bonds and charge distribution was investigated; the energy of the Rh-Rh bonds was estimated.

In the search for new f–d luminescent complexes of Eu(II) and Yb(II) the metathesis reactions of diiodides of these metals with perfluorinated 2-mercaptobenzothiazolates of alkali metals were studi...

Sm, Er, and Yb complexes containing anionic (4,5,6,7-tetrafluorobenzothiazol-2-yl)-2-(3,4,5,6-tetrafluoro)phenolate (SONF) and 3-(2-benzothiazol-2-yl)-2-naphtholate (NpSON) and neutral 1,10-phenathroline or 2,2'-bipyridine ligands were synthesized. The structures of complexes Yb(SONF)2-(NpSON)(DME)1.5 (II) and previously synthesized Er(SONF)3(DME) (I) were determined by X-ray diffraction (CIF files CCDC nos. 1972769 and 1972770, respectively). Upon excitation by light at λ 405 nm, all complexes showed luminescence of the ligands and Ln3+ ions. The OLED devices based on samarium complexes showed moderate intensi metal-centered emission of moderate intensity at a 19 V voltage.

In this article, we report on the results of experimental and theoretical (DFT calculation of an isolated molecule) investigation of electron density in a triphenylantimony disorbate complex (triphenylantimony bis(hexa-2,4-dienoate), Ph3Sb(O2CCH=CH–CH=CH–CH3)2 (1)). A topological analysis of the electron density was carried out in the framework of the quantum theory of atoms in molecules (QTAIM), which allows to study the nature of chemical bonds and the molecular graph in Ph3Sb(O2CCH=CH–CH=CH–CH3)2 complex. The molecular graph is an important tool for determining the interacting atoms. However, the molecular graph of the triphenylantimony disorbate complex did not show the presence of the “expected” intramolecular interactions between the antimony atom and the carbonyl oxygen one. Such a situation can be caused by electron density low curvature between these atoms. It is extremely difficult case, and sometimes it is not possible to find all the “expected” bond paths and critical points (3,−1). Thus, the molecular graph for this class of compounds does not provide a definitive picture of the chemical bonding and should be complemented with other descriptors, such as а source function (SF) and non-covalent interaction (NCI) index. It was found that in some cases using the SF on the NCI isosurface allows to interpret intramolecular interactions in the absence of a bond critical point more correctly. In this article, presence of intramolecular interaction in the absence of a bond critical point between the antimony atom and the carboxylate oxygen one was shown. The carboxylate fragment always acts as a source of the electron density for the Sb…O(carbonyl) interactions, whereas the antimony atom can be both a source and a sink for it.

By crystallization of sterically hindered 1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino]acenaphthene (dbhmp-bian) (1) from tetrahydrofuran (THF) or acetone two crystalline forms of (dbhmp-bian)(THF)3(1a) and dbhmp-bian (1b) are isolated and structurally characterized. In DFT calculations (B3LYP/6-31G(d) level), no significant differences between the electronic structures of 1 and some other Ar-bian ligands (Ar = 2,6-Me2-C6H3; 2,6-Et2-C6H3; 2,6-iPr2-C6H3) are revealed. HOMO and LUMO energies of these compounds are in the ranges −5.60 eV … −5.51 eV and −2.07 eV … −2.04 eV respectively. The geometric parameters of the diimine moiety of the ligands obtained from DFT calculations and XRD data are almost identical.

The reactions of H

Three new sterically hindered acridin-4-ols have been prepared by alkylation of anilines with 3,5-di-tert-butyl-6-methoxymethylcatechol followed by oxidation of the reaction mixture. Formation of the acridine moiety was found to occur in the course of oxidation of the intermediate (anilinomethyl)catechol on contact with air in the Et2O/H2O–KOH system. The molecular structure of two acridin-4-ols was determined by single-crystal X-ray diffraction.

The reaction of dialane (dpp-Bian)Al–Al(dpp-Bian) (1) (dpp-Bian is dianion of 1,2-bis[(2,6-diisopropylphenyl)imino]-acenaphthene) with 1 mol equiv of 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene ...

N‑heterocyclic phospholes based on N,N-disubstituted 9,10-phenanthrenediimines were synthesized. Dimeric 1,3,2-diazaphospholes were obtained by reduction of 2-bromo diazaphospholes. In case phenanthrediimine with the most sterically hindrance, diphosphole can dissociate into phosphorus-centered radicals at record low temperatures (220 K) for this class. This behavior will allow the synthesis of new metal complexes and phosphorus-organic compounds under mild conditions.

Experimental and experimental–theoretical studies (using the molecular invariom) of the electron density distribution are performed for the η6-[3-acetyltetrahydro-6-phenyl-2Н-1,3-oxazine]tricarbonylchromium(0) complex. The topological characteristics of the electron density (ρ(r), ∇2ρ(r)) at the critical points (3, –1) coincide in the experimental and experimental–theoretical distributions within the “transferability indices.” The experimental–theoretical study more reliably localizes the “expected” critical points (3, –1) between the chromium atom and arene ligand.

Experimental and experimental-theoretical studies (the invariom approach, whole-molecule aspherical scattering factors) of the electron density distribution were carried out to compare its topological characteristics at the critical points (3, −1) of the NCN-(2-pyridinecarbonitrile)-(3,6-di-tert-butylcatecholato)triphenylantimony(v) complex. The topological characteristics of the electron density distribution at the critical points (3, −1) and the atomic volumes determined in experimental studies are almost in quantitative agreement with the results of experimental-theoretical investigation.

Three-nuclear clusters Nd2LnI5(S2)(S2N2)(THF)9 (Ln = Tb, Tm) were prepared by the disproportionation reaction of iodide-nitride [(NdI)3N2](THF)6 with LnI3(THF)3 in the presence of sulfur. Molecule of the cluster contains a flat inorganic core formed by two Nd and Ln atoms connected by dithiadiazine group. One of the Nd atoms is bound to the Ln3+ ion, besides terminal N atom of the bridge S2N2 fragment, by a bridge fragment S2. The second Nd atom is coordinated by two iodine anions and SN group forming unusual NdSN tree-member cycle. Structure of inorganic framework of the complexes is similar to that of earlier obtained monometallic analogues Ln3I5(S2)(S2N2)(THF)10 (Ln = Nd, Dy). In both new clusters the Ln atoms have the same coordination surrounding consisting of one iodine anion, S2 group and N atom of dithiadiazine ligand and occupy in the framework Nd2Ln(S2)(S2N2) the same position which corresponds to the lowest energy of the molecule. The nitride [(NdI)3N2](THF)6 in the presence of sulfur easy reacts as well with triiodides of La and Sm. Products isolated in these reactions do not form crystals suitable for X-ray study but the data of elemental analysis, fragment analysis, the found Nd: Ln ratio, spectroscopic and magnetic measurements allow to conclude that the structure of La, Sm products is similar to that of the above Tb, Tm analogs.

Heterolanthanide clusters Nd2LnI5(S3)(S2N2)(THF)9 (Ln = Dy, Yb) are synthesized by the reactions of (NdI)3N2 with DyI3 or YbI3 and sulfur in a THF solution. X-ray diffraction analysis revealed that the structure of the complexes is similar to the structure of Nd2LnI5(S3)(S2N2)(THF) 9 obtained earlier (Ln = Tb, Tm). The ion Dy3 + in the molecule is coordinated by the iodine atom, the S2 group and the terminal N atom in the resulting S3N2 ligand. Cluster Nd2YbI5(S3)(S2N2)(THF)9 of the same structure was obtained as well when YbI2 was used instead of YbI3. Possible pathways of the reactions are discussed. UV excitation of Nd2DyI5(S3)(S2N2)(THF)9 causes low-intensity emission of Dy3+ ions: two bands at 480 and 580 nm. Magnetic measurements showed no exchange interaction in the obtained clusters.

A tris-dioxolene manganese complex was synthesized and characterized (dioxolene- mono- and dianions of 3,6-DBQ-pipe, which is 3,6-di-tert-butyl-o-benzoquinone having a N,N’-piperazine bicycle as substituent in 4,5-positions). According to the bonds lengths distribution in the chelate cycles of the ligands the complex was identified as a bis-o-semiquinone-catecholato derivative of Mn(IV). Variable temperature magnetic susceptibility measurements indicate one unpaired electron per complex molecule as a result of strong intramolecular antiferromagnetic exchange interactions. The bis-o-semiquinone-catecholato manganese complex interacts with pyridine substituted by a nitronyl-nitroxide moiety forming a six-coordinate compound. The X-ray structural diffraction study of the complex executed at 100 K indicates a trans-arrangement of the pyridine ligands and the two catecholato dianionic chelates. Variable temperature magnetic susceptibility measurements of the complex with nitronyl-nitroxide give a magnetic moment of 5.5 µB which cannot be achieved in the spin system S = 3/2 (Mn4+) and 2 × S = 1/2 (two nitronyl-nitroxides). A valence tautomeric interconversion is proposed when the high multiplicity states [Mn3+(catecholate)(semiquinone)] and [Mn2+(semiquinone)2] are partly populated.

Recently there has been a great deal of interest and associated research into aspects of the coordination chemistry of lanthanides and bismuth&mdash, elements that show intriguing common features. This work focuses on the synthesis and characterization of a novel bismuth(III) polynuclear metallamacrocyclic complex derived from aminohydroxamic acid, in order to compare the coordination ability of Bi3+ with the similarly sized La3+ ions. A polynuclear tyrosinehydroximate Bi(OH)[15-MCCu(II)Tyrha-5](NO3)2 (1) was obtained according to the synthetic routes previously described for water-soluble Ln(III)-Cu(II) 15-MC-5 metallacrowns. Correlations between structural parameters of Bi(III) and Ln(III) complexes were analyzed. DFT calculations confirmed the similarity between molecular structures of the model bismuth(III) and lanthanum(III) tyrosinehydroximate 15-metallacrowns-5. Analysis of the electronic structures revealed, however, stronger donor-acceptor interactions between the central ion and the metallamacrocycle in the case of the lanthanum analogue. Thermochromic properties of 1 were studied.

Herein, we present the synthesis, single-crystal X-ray structures, and spectroscopic properties for the 1:1 donor-acceptor complexes of 1,2,4,5-tetracyanobenzene (TCNB) with annelated 3a,6a-diaza-1,4-diphosphapentalenes (DDPs) based on cyclohexanone azine (

In order to obtain molecular Ce(III) complexes which emit red light by f–d transitions the azolyl-substituted thiophenolates were used as the ligands. The thiophenolate Ce(III) complexes were synthesized by the reaction of Ce[N(SiMe3)2]3 with respective thiophenols 2-(2′-mercaptophenyl)benzimidazole (H(NSN)), 2-(2′-mercaptophenyl)benzoxazole (H(OSN)) and 2-(2′-mercaptophenyl)benzothiazole (H(SSN)) in DME media. The structures of the benzimidazolate (Ce(NSN)3(DME)) and benzothiazolate (Ce(SSN)3(DME)) derivatives were determined by X-ray analysis which revealed that the cerium ion in the molecules is coordinated by one DME and three anionic thiophenolate ligands. The lanthanum complex La(OSN)3(DME) has been synthesized similarly and structurally characterized. It was found that the solids of Ce(SSN)3(DME) and Ce(OSN)3(DME) exhibit a broad band photoluminescence peaking at 620 nm which disappears upon solvatation. With an example of OSN derivatives it was proposed that this behaviour is caused by the blue shift of the f–d transition of Ce3+ ions.

A series of homo and heterometallic La, Li and Na complexes with 2-(2-benzoxyazol-2-yl)phenolate (L) ligands were synthesized using La[N(SiMe3)2]3 and M[N(SiMe3)2] (M = Li, Na) or La(Cp)3 as starting materials for La2(L)6 (1), La2(L)6(bipy) (2), La(L)2Cp(DME) (3), La2Li(L)7 (4), Li(L) (5), Na(L) (6). Photoluminescent (PL) properties of these compounds, staring phenol H(L) as well as previously obtained complex LaNa(L)4(DME)2 (7) were studied at 300 and 77 K. Molecular structure of 2, 3 and 4 were determined by X-ray analysis. All the compounds in THF solution at 300 K upon UV excitation (370 nm) revealed a bright fluorescence in the range 430–460 nm and moderate phosphorescence as a shoulder at about 500 nm. The total quantum yield (QY) is 1–35%. At 77 K all lanthanum compounds (except 3) in THF solution exhibit weak or moderate fluorescence but intense phosphorescence (τ 3.5 – 95.8 ms). The PL spectra of solid samples at 300 K strongly differ from those of solutions, apparently due to the effects of crystal packing, the shape and size of the crystals. The emission of H(L) is most intensive but the PL of 1 has lowest efficiency. It is assumed that phosphorescence occurs from excimers and exciplexes, the formation of which in the compounds studied has been confirmed by X-ray diffraction analysis.

In the search for a way to organic up-converter materials the complex [(OON)2Er(THF)](μ-O)[(OON)2Yb(THF)] with the (benzoxazol-2-yl)phenolate (OON) ligand was synthesized. Upon excitation by laser with λex 405 nm light the complex displayed only emission of the Yb3+ ion indicating the lack of energy transfer from Yb to Er. To develop a method for preparation of other up-converter materials the complexes [Yb4(SON)8(μ4-O)(OH)2 and [Eu4(OON)10Li2(3-O)2] with (benzothiazol-2-yl)phenolate (SON) and (benzoxazol-2-yl)phenolate ligands were synthesized using water as a co-reagent. The X-ray study revealed that the clusters contain μ2-O, μ3-O and μ4-O bridges and short Ln…Ln contacts. These modelling syntheses showed that the method is applicable for preparation of potential up-convertion materials with Ln-O-Ln’ groupings.

An approach based on the simultaneous use of a source function and a noncovalent interaction index for studying interatomic interactions in the absence of bond critical points is offered. This approach comprises the selection of reference points for the source function on the noncovalent interaction index isosurface.

New triphenylantimony(V) catecholates 1-3 based on 3-formyl-substituted catechols L1-L3 have been synthesized and characterized (L1 is 2,3-dihydroxy-4,6-di-tert-butyl-benzaldehyde, L2 is 2,3-dihydroxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene-1-carbaldehyde, and L3 is 2,3-dihydroxy-4,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene-1-carbaldehyde). The crystal structures of complexes 1, 2 have been determined by single-crystal X-ray analysis. It was found that the coordination sphere of the antimony atom is supplemented to 6 due to the intermolecular donor-acceptor bond of Sb…O with the formyl oxygen of the neighboring catecholate molecule. As a result, the formation of 1D-polymer structures for 1, 2 is observed.

A new monoiminoacenaphthenone 3,5-(CF3)2C6H3-mian (complex 2) was synthesized and further exploited, along with the already known monoiminoacenaphthenone dpp-mian, to obtain oxidovanadium(IV) complexes [VOCl2(dpp-mian)(CH3CN)] (3) and [VOCl(3,5-(CF3)2C6H3-bian)(H2O)][VOCl3(3,5-(CF3)2C6H3-bian)]·2.85DME (4) from [VOCl2(CH3CN)2(H2O)] (1) or [VCl3(THF)3]. The structure of all compounds was determined using X-ray structural analysis. The vanadium atom in these structures has an octahedral coordination environment. Complex 4 has an unexpected structure. Firstly, it contains 3,5-(CF3)2C6H3-bian instead of 3,5-(CF3)2C6H3-mian. Secondly, it has a binuclear structure, in contrast to 3, in which two oxovanadium parts are linked to each other through V=O···V interaction. This interaction is non-covalent in origin, according to DFT calculations. In structures 2 and 3, non-covalent π-π staking interactions between acenaphthene moieties of the neighboring molecules (distances are 3.36–3.40 Å) with an estimated energy of 3 kcal/mol were also found. The redox properties of the obtained compounds were studied using cyclic voltammetry in solution. In all cases, the reduction processes initiated by the redox-active nature of the mian or bian ligand were identified. The paramagnetic nature of complexes 3 and 4 has been proven by EPR spectroscopy. Complexes 3 and 4 exhibited high catalytic activity in the oxidation of alkanes and alcohols with peroxides. The yields of products of cyclohexane oxidation were 43% (complex 3) and 27% (complex 4). Based on the data regarding the study of regio- and bond-selectivity, it was concluded that hydroxyl radicals play the most crucial role in the reaction. The initial products in the reactions with alkanes are alkyl hydroperoxides, which are easily reduced to their corresponding alcohols by the action of triphenylphosphine (PPh3). According to the DFT calculations, the difference in the catalytic activity of 3 and 4 is most likely associated with a different mechanism for the generation of ●OH radicals. For complex 4 with electron-withdrawing CF3 substituents at the diimine ligand, an alternative mechanism, different from Fenton’s and involving a redox-active ligand, is assumed.

A set of new heterometallic complexes of composition of ErYb(L) 6 and Er 0.67 Yb 1.33 (L) 6 (L = 3-(2-benzothiazol-2-yl)-2-naphtholate (NpSON), pentafluorophenolate (C 6 F 5 O) and hexafluoro-iso-propoxide ((CF 3 ) 2 CHO) were synthesized and characterized by X-ray diffraction (L= (CF 3 ) 2 CHO), MALDI-TOF, 19 F NMR (L= C 6 F 5 O, (CF 3 ) 2 CHO), IR and elemental analyses. All the compounds exhibited emission of Er 3+ at 1530 nm upon direct excitation of Yb 3 + by the laser irradiation with λ ex = 910 and 980 nm that shows the intramolecular energy transfer Yb 3+ →Er 3+ . In the luminescence spectra of Er 0.67 Yb 1.33 [(CF 3 ) 2 CHO] 9 besides the band at 1530 nm the short-wavelength emission at 550 nm was found, which indicates upconversion phenomenon. Excitation of ytterbium in the mixture of monometallic iso -propoxides Er 2 [(CF 3 ) 2 CHO] 6 and Yb 2 [(CF 3 ) 2 CHO] 6 does not lead to luminescence of erbium ions which confirms intramolecular character of energy transfer in Er 0.67 Yb 1.33 [(CF 3 ) 2 CHO] 6 .