Oxidation reactions of an anionic gallium(i) N-heterocyclic carbene analogue with group 16 compounds

Abstract

The reactivity of an anionic gallium(I) heterocycle, [K(tmeda)][:Ga{[N(Ar)C(H)]₂}], Ar = C₆H₃Prⁱ₂-2,6, towards sources of elemental chalcogens and diorgano-dichalcogenides has been investigated and comparisons drawn with the reactivity of the valence isoelectronic N-heterocyclic carbene class of ligand. The reactions of the heterocycle with N₂O or (Te)PEt₃ yielded the dimeric, dianionic gallium(III) complexes, [K(L)]₂[(µ-E)Ga{[N(Ar)C(H)]₂}]₂, E = O, L = tmeda; E = Te, L = THF. Treatment of [K(tmeda)][:Ga{[N(Ar)C(H)]₂}] with the diphenyl dichalcogenides, PhEEPh, E = Se or Te, gave the one dimensional polymer, [K[(PhSe)₂Ga{[N(Ar)C(H)]₂}]]_∞ and the monomeric complex, [K(OEt₂)₃][(PhTe)₂Ga{[N(Ar)C(H)]₂}], respectively. The X-ray crystal structures of the four complexes are reported.