A complex of gallium with a Schiff base - bis(orthoquinone) ligand

The electrochemical oxidation of gallium in a cell containing a solution of 3,5-di-tert-butylcatechol (H(2)dbc) in a mixture of liquid ammonia and diethyl ether gives rise to the complex Ga(dbqdi)(2), where dbqdi is a tridentate ligand formed by the condensation of two molecules of H(2)dbc and ammonia. The same paramagnetic molecule can be prepared by treating GaCl3 with H(2)dbc in ethanol with concentrated aqueous ammonia, with subsequent aerial oxidation. The crystal parameters are triclinic, space group P (1) over bar, a = 11.6140(8), b = 12.3415(9), c = 20.765(1) Angstrom, alpha = 89.491(1)degrees, beta = 74.287(1)degrees, gamma = 75.748(1)degrees, Z = 2, and R = 0.0542 for 7578 unique reflections. The structure, which is based on a GaO4N2 kernel, is discussed on the basis of crystallographic and ESR results.