Isolation and characterization of a blue coloured three coordinate Cu(i)-radical complex with an S3 donor set

Abstract

A stable three coordinate Cu(I)-radical complex with an S₃ donor set having the general formula of [Cu^I(S–NHCH)(SS–NHCS)] (1) was isolated as dark blue needles. Interestingly, this complex possesses a zwitterionic ligand, ⁻S–NHCH⁺, which is coordinated to the central Cu(I) ion via its S-atom [⁻S–NHCH⁺ C4-thiolate functionalized C2-protonated zwitterionic N-hetero cyclic carbene; SS–NHCS˙⁻ NHC-based dithiolene radical anion]. 1 has been structurally characterized by single-crystal X-ray diffraction, and further characterized by UV-vis, IR, XPS, and EPR spectroscopy. 1 has also been studied by quantum chemical calculations.