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The complex formation of TiF4 with the phosphorylated ketone Ph2P(O)CH(Me)CH2C(O)Et (L), containing an asymmetric carbon atom in the aliphatic hydrocarbon group and representing a racemic mixture of enantiomers, was studied by 19F{1H} and 31P{1H} NMR spectroscopy. The composition of complexes formed in the solution was determined; analysis of the 19F NMR spectra resorting to the heterotropicity concept was used to assign the resonance lines to two chiral optically active racemic and meso-stereoisomers of cis-TiF4L2. The configurations of enantiomers of the monodentate ligand coexisting in the coordination sphere were found to have a crucial effect on the axial fluorine atoms of mixed octahedral cis-tetrafluoro d0 transition metal complexes. A new efficient method was developed for the synthesis of ligand L.

Some peculiarities of the effect of enantiomers of the monodentate ligand on the stereoisomerism of the mixed octahedral tetrafluoride complexes of d0-transition metals are established by the 19F{1Н} and 31Р{1Н} NMR methods for the complex formation of TiF4 with Ph2P(O)CH2CH(OH)Me (L) having the asymmetric carbon atom in the aliphatic hydrocarbon radical and being a racemic mixture of enantiomers in СН2Сl2. The compositions of the complexes formed in solutions are determined. The conclusion about the relative stereochemical configuration of the chiral and meso-stereoisomers of the geometric isomers of the TiF4L2 octahedral complex is based on an analysis of the 19F NMR spectra using the heterotropic concept.

Quantum-chemical calculations of the structure and relative thermodynamic stability of tetranuclear clusters MxN4 – xO6(OMе)10 (M, N = Re, Ru; x = 4–0) including geometric isomers of bimetallic clusters are performed to establish the possibility of replacing Re atoms by Ru atoms while maintaining a cyclic tetranuclear structure. As the initial model, the structure of Re4O6(OPri)10 was chosen which is an almost regular rhombus. The values of the metal–metal and metal–oxygen interatomic distances are calculated, and features of their variation under the transition from mononuclear to heteronuclear clusters and from neutral clusters to anions are discussed. Differences between the relative thermodynamic stability of homometallic and heterometallic tetranuclear clusters, including the geometric isomers of the latter, are discussed.

Effect of enantiomers of a monodentate ligand on the stereoisomerism of mixed octahedral cis-tetrafluoro complexes of d0 transition metals has been studied by 19F{1H} and 31P{1H} NMR by the example of TiF4 complexation in CH2Cl2 with Ph2P(O)CH2CH(OH)Me (L) containing asymmetric carbon atom in the aliphatic hydrocarbon group that constitutes a racemic mixture of enantiomers. Composition of complexes formed in solution has been determined, conclusion has been drawn on the relative stereochemical configuration of the chiral and meso stereoisomers of octahedral complex cis-TiF4L2 on the basis of analysis of 19F NMR spectra, using the heterotropism concept.

The reaction of TiF4 with PhP(O)[CH2C(O)NMe2]2 in CH2Cl2 has been studied by 19F NMR spectroscopy. It has been found that the major reaction products are chelate tetrafluoro complex (η2-L)TiF4 where the ligand is coordinated to the titanium ion through the P=O and C=O groups and cis-TiF4(ОР···L)2 where both ligands are coordinated to the central ion through the more basic P=O groups. Spectral features of the tetrafluoro chelate have been studied, which have been attributed for the first time to the appearance of a chiral center at chelate coordination. The character of manifestation of conformational isomerism of the chelate ring and chiral center in the chelating ligand in mixed octahedral complexes of d0 transition metal fluorides in 19F NMR spectra is discussed.

Molybdenum dioxide (Mo2) synthesized through thermal decomposition of the [MoO2(i-C3H7NHO)2] complex and containing a nanosized fraction has been studied by MALDI-TOF. The composition of clusters of lower nonstoichiometric molybdenum oxide cations in the gas phase has been determined, and theoretical calculations of the thermodynamic stability and structure of the isomers of the most symmetric structures have been performed. Molecular orbitals of the cationic and neutral clusters Mo5O8 and Mo5O9 have been examined, and the aromaticity of the Mo-Mo bonds in metallacycles has been demonstrated.

New complexes of uranyl with diethylglyoxime have been synthesized and studied. A feature of these complexes is the tetradentate bridging coordination of the ligand in both cis- and trans-conformations. The structure of organic ligand C6H12N2O2 and binuclear complex (CN3H6)4[(UO2)2(C6H10N2O2)(CO3)(C2O4)2] ∙ H2O have been determined by X-ray diffraction.

The crystal structure of TiF4[(Ph2P(O)CH2CH2C(O)NMe2)] chelate (I) was studied by X-ray crystallography, which revealed four crystallographically independent complex molecules of similar structure (1–4). It was found that the molecules are only slightly different in the bond lengths between the coordinated atoms and the central titanium ion and considerably different in the geometry of the seven-membered TiOPCCCO chelate ring. The geometry of the chelate rings was found to be almost identical in each pair of complexes 1, 2 (A) and 3, 4 (B), and a conclusion was drawn on the presence of two conformational isomers (A and B) of the chelate complex. Quantum chemical calculations of the relative thermodynamic stability of molecules 1–4 were performed, and their geometry optimization led to one theoretical structure. The comparison of the chelate ring geometry in the theoretical structure and in conformers A and B revealed that the conformation of the theoretical chelate ring coincides with that of conformer A.

Quantum-chemical calculations of the structures and thermodynamic stabilities of isomers of molecular clusters of lower Mo chlorides Mo13Cl24, Mo13Cl26, and Mo13Cl30, as well as of the Mo13Cl26− anion of cuboctahedral or icosahedral structure, have been performed by the DFT B3LYP method with the use of the Lanl2dz basis set for the Mo atoms and the 631G(d) basis set for the Cl atoms. The highest symmetry polyhedra are considered: Mo13Cl30 and Mo13Cl24 have a structure of centered icosahedron and cuboctahedron with bridging Cl atoms sitting atop the midpoints of 30 and 24 edges, respectively. In both cases, calculations lead to a rapid increase in the Mo-Mo distance to the values that are evidence of the absence of metal-metal bonds; hence, the cluster structure, in its classical meaning, is not retained. Both the neutral cluster Mo13Cl26 and the Mo13Cl26− anion—a symmetric icosahedron, in which Cl ions sit atop the centers of 20 faces and 6 Cl atoms are terminal, and a cuboctahedron, in which 14 Cl atoms are located on the three- and fourfold axes over the centers of molybdenum faces and 12 terminal Cl atoms are located on twofold axes. For both the neutral cluster and the anion, stable structures have been obtained. In both cases, the total energies are lower for the initial icosahedral configuration.

Uranyl complexes with ethylmethylglyoxime were studied. The structure of (CN3H6)4[(UO2)2(CO3)(C2O4)2(C5H8N2O2)] · 1.5H2O was determined by X-ray crystallography. The structure of the complex is binuclear with a double carbonate dioximate bridging fragment.

Uranylaqua complexes with N-methyl-, N-ethyl-, N-isopropyl-, and N,N-dimethylhydroxylamines were studied. The structure of [UO2{(CH3)2NO}2(H2O)2] was determined by X-ray crystallography. The N, N -dimethylhydroxylaminate ion is coordinated to uranyl through the nitrogen and oxygen atoms with the formation of a three-membered chelate ring.

Unusual coordination modes of 1,2-cyclohexane dionedioxime in uranyl complexes, i.e., tridentate chelating/bridging and (E, Z)-pentadentate chelating/bridging ones, were established by X-ray crystallography of single crystals of (CN3H6)3[(UO2)2(C6H9N2O2)(C6H8N2O2)(C2O4)2] · 2H2O and [(UO2)2(C6H8N2O2)2(H2O)3] · 2H2O. The conditions of the emergence of such coordination modes were determined. The possibility of (E/Z) izomerization of α-dioximes in reactions of uranyl complexes.

The interaction of uranyl compounds with different α-dioximes has been studied. Uranyl complexes with glyoxime, methylglyoxime, dimethylglyoxime, and 1,2-cyclohexanedionedioxime have been synthesized. The X-ray diffraction study of single crystals of [UO2(C3H5N2O2)2{(NH2)2CO}2], [UO2(C6H9N2O2)2(H2O)2] · H2O, [UO2(C6H9N2O2)2(H2O)2] · 6H2O, and [UO2(C6H9N2O2)2(H2O)2]2(CH3CONH2)2 · 6H2O showed a bidentate cyclic coordination of α-dioximes to the central atom through only one oxime group

The powder and single crystal of potassium titanyl phosphate KTiO(PO4) have been studied by 39K NMR. The quadrupole coupling and 39K isotropic chemical shift parameters have been calculated. The number of formula units in the unit cell of potassium titanyl phosphate is suggested to be equal to the number of magnetically nonequivalent positions of potassium atoms in the lattice.

The interaction of substituted o-benzoquinones with tin and titanium tetrafluorides leads to the formation of the o-semiquinolate complex of the corresponding metal trifluoride. The tin-containing complexes exist in two forms of an octahedral structure differing in the mutual location of the added ligands; the ratio of these forms depends on the nature of the solvent. The titanium-containing complexes are obtained in a single form, owing to the different ligand repulsion energy when the size of the central atom is changed.