The crystal and molecular structure of catena-3,5-dimethylisoxazole-μ-dichlorodicopper(I), a compound reacting with molecular oxygen

Abstract

The title compound has been prepared by an in situ method involving the reduction of cupric ions and the cyclisation of 2,4-pentanedioxime. The colourless crystals were found to be sensitive to molecular oxygen and the initial dark brown product formed on exposure to the gas has a new i.r. band at 1083 cm −1 taken as indicative of dioxygen bonding. An x-ray structural determination of the colourless compound ( a = 3.8660, b = 18.543, c = 11.888 Å, β = 92.65°, P2 1/c, 4 molecules of L(CuCl) 2) revealed a linear polymeric structure with the metal atoms bound by chlorine bridges. Each copper has a distorted tetrahedral donor arrangement but only half of them have the organic group, found to be 3,5-dimethylisoxazole, as a ligand. The stoichiometry is thus L(CuCl) 2 and it seems likely that the sensitivity to dioxygen is a consequence of the compound's relationship with CuCl rather than to the influence of the isoxazole.