First example of a Cu(i)–(η2-O,O)nitrite complex derived from Cu(ii)–nitrosyl

Abstract

Copper(II) complex, 1, of the bidentate ligand, L [L = bis(2-ethyl-4-methyl-imidazol-5yl)methane] has been synthesized and structurally characterized. Addition of nitric oxide gas to a degassed acetonitrile solution of 1 yielded the corresponding copper(II)–nitrosyl complex, 2. In acetonitrile, complex 2 on reaction with water afforded the corresponding copper(I)–nitrite complex, 3. Single crystal structure of complex 3 reveals the bidentate nitrite (η²-O,O) bonding. This is the first example of a structurally characterized Cu(I)–(η²-O,O)nitrite complex with N-donor ligand. The sequence of the formation of these complexes is just the reverse of the key steps of the postulated nitrite reduction cycle by CuNiRs.