Role of bifunctional N/S bridging in the association of metals; syntheses and structures of heterobimetallic [Ph3P)2CuL2Li(thf)2]·thf and tetrameric [{CuL(PPh3)}4](L = 1,3-benzoxazoline-2-thionate, thf = tetrahydrofuran)
Abstract
Nucleophilic substitution of the cp (η-C5H5) ligand of [Cu(cp)(PPh3)] with LiL (L = 1,3-benzoxazoline-2-thionate) gave the heterobimetallic complex [(Ph3P)2CuL2Li(thf)2]·thf 1(thf = tetrahydrofuran), the ligand-transfer reaction of which with CuCl2 generated the tetrameric cage complex [{CuL(PPh3)}4]2. The crystal structures of these complexes revealed that the association of the metal centres occurs by a variety of ligand co-ordination modes (µ-S, N; N, µ-S; µ3-S). Electrochemical measurements have been used to probe the nature of the species present in solution.