Novel chalcogenide vanadium complexes with β-diimine ligand: synthesis and structural studies

Three new chalcogenide vanadium complexes with a β-diketiminate ligand have been synthesized by reduction of the elemental chalcogens (S, Se, Te) with [(µ-η ⁶ :η ⁶ -toluene){V(nacnac)} ₂ ] (1) (nacnac = HC(C(Me)NC ₆ H ₃ - ⁱ Pr ₂ ) ₂ ). The structures of the sulfide and selenide complexes [((nacnac)V = E) ₂ (μ,ƞ ² -E ₂ )] (E = S (2), Se (3)) are similar; the chalcogenides act both as bridging (E ₂ ^2- ) and terminal (E ^2- ) ligands. In compound [V ₂ (µ-Te) ₂ (nacnac) ₂ ] (4), all tellurium atoms are present only as bridging Te ^2- ligands. The compounds have been characterized by IR-spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The possibility of the formation of additional V = Te bonds in 4 has been studied using Hirshfeld analysis. It has been found that the difference in the reactivity of 1 towards Te is not due to the steric hindrance.