Том 45, № 6 (2019)

This review describes approaches to the targeted multistep synthesis of coordination compounds exemplified by Group 5 and 6 metal chalcogenide and oxide clusters and polynuclear compounds. Methods for the introduction of two different chalcogen atoms and methods for the synthesis of mixed oxide chalcogenide complexes are considered.

The computer simulation (DFT UTPSSh/6-311++G(d,p)) of the structures and the energy and magnetic characteristics of the binuclear cobalt complexes bearing the tetraazamacrocyclic base and the di-o-quinone ligand containing as a linker the acene group is performed. Thus built molecules can undergo thermally switchable rearrangements of the spin states of the metal-centered moieties and photoinitiated single–triplet transitions of the acene linker. The possibility to control the magnetic properties of the studied coordination compounds using various external effects makes it possible to consider them as molecular switches.

Tungsten cycloheptatrienyl complexes (η⁷-C₇H₇)W(CO)₂I (I), [(η³-C₇H₇)W(CO)₂(CH₃CN)₃]PF₆ (II), and [(η⁷-C₇H₇)W(CO)₂(CH₃CN)]PF₆ (III) (CIF files CCDC nos. 1875096 (I), 1875097 (II), 1875098 (III)), characterized earlier only by spectroscopic methods, were prepared and studied by X-ray diffraction. The tris(acetonitrile) complex II can lose two acetonitrile ligands in both coordinating and non-coordinating solvents with the η³ → η⁷ change in the hapticity of the cycloheptatrienyl ring to be converted to III. The reverse ligand attachment process with the η⁷ → η³ change in the hapticity of the cycloheptatrienyl ring takes place upon the dissolution of monoacetonitrile complex III in acetonitrile. The electron-compensating η³ ↔ η⁷ change in the hapticity of the tropylium ligand is reversible.

The structural features of eleven mononuclear octahedral d²-Re(V) monooxo complexes with tridentate chelating (O,P,O and O,P,N) ligands, [ReO\(\left( {{\text{L}}_{{{\text{tri}}}}^{m}} \right)\)\(\left( {{\text{L}}_{{{\text{bi}}}}^{n}} \right)\)], [ReO\(\left( {{\text{L}}_{{{\text{tri}}}}^{m}} \right)\)Cl₂], and [ReO\(\left( {{\text{L}}_{{{\text{tri}}}}^{m}} \right)\)-Cl(PPh₃)], are considered. The Re–O\({{\left( {{\text{L}}_{{{\text{tri}}}}^{m}} \right)}_{{trans}}}\) bond lengths are commensurable (or somewhat shorter) with the Re–O\({{\left( {{\text{L}}_{{{\text{tri}}}}^{m}} \right)}_{{cis}}}\) or Re–O(ST) bond lengths, which is indicative of the presence of pseudo-dioxo ReO₂ groups with increased bond orders for both trans-arranged Re–O bonds. In the structures of two compounds, the Re–O\({{\left( {{\text{L}}_{{{\text{bi}}}}^{{\text{2}}}} \right)}_{{trans}}}\) bonds are, on average, 0.094 Å longer than Re–O(ST) and 0.189 Å longer than Re–O\({{\left( {{\text{HL}}_{{{\text{bi}}}}^{{\text{3}}}} \right)}_{{cis}}}\), in accordance with the structural consequences of the trans-effect of a multiply bonded oxo ligand.

Two Mo(VI) clusters, (H₂L)₃[Mo₇O₁₂(μ₂-O)₈(μ₃-O)₄] · 3H₂O (I) and (H₂L)₂[Mo₈O₁₄(μ₂-O)₆(μ₃-O)₄(μ₅-O)₂] · 4DMF (II), derived from MoO₂(Acac)₂ and N-methylethane-1,2-diamine (L) in water and DMF, respectively, are reported. The complexes were characterized by single crystal structure analysis (CIF files CCDC nos. 1846032 (I) and 1443681 (II)). Compound I contains a seven nuclear molybdenum(VI) complex anion, three H₂L cations and three water molecules. Compound II contains an eight nuclear molybdenum(VI) complex anion, two H₂L cations and four DMF molecules. All Mo atoms are in octahedral coordination. Complex I crystallized as monoclinic space group P2₁/n with unit cell dimensions a = 12.3005(12), b = 17.3944(17), c = 15.9446(16) Å, β = 93.862(2)°, V = 3403.8(6) ų, Z = 4, R₁ = 0.0795, wR₂ = 0.1677. Complex II crystallized as monoclinic space group P2₁/n with unit cell dimensions a = 11.1465(13), b = 16.460(2), c = 12.7942(16), β = 97.368(2)°, V = 2328.0(5) ų, Z = 2, R₁ = 0.0362, wR₂ = 0.0754. The complexes were tested as catalyst for the oxidation of olefins and showed effective activity.