Valence isomerization. Synthesis and characterization of cobalt and nickel complexes with non-innocent N2S2 ligand

The reactions of 2-phenylbenzothiazoline with [M(CH3COO)(2)].4H(2)O (M = Co(II) and Ni(II)) afford the complexes [M(phbt)(2)] (phbt = 2-(phenylmethyleneamino)benzenethiolato) via a ring opening reaction of 2-phenylbenzothiazoline. Spectroscopic data indicate that the cobalt and nickel atoms occupy a tetrahedral and a square planar N2S2 environment, respectively. The single crystal X-ray structure of [Ni(phbt)2] is redetermined and this complex shows a monohelical geometry. Crystal data: [Ni(phbt)(2)], monoclinic, C2/c, a = 23.065(4); b = 6.924(2); c = 13.809(2) Angstrom; beta = 102.64(1)degrees; V = 2152.0(9) Angstrom(3); Z = 4, R = 0.052 (R-w = 0.050). The toluene solution of [Co(phbt)(2)] and that of [Ni(phbt)(2)] lead to the complexes [Co(ddbt)] and [Ni(ddbt)] (ddbt = bis-2,2'-(1,2-diphenylethylenediimine)benzenethiolato) through the carbon-carbon bond formation, respectively. The structural features of [M(ddbt)] (M = Co and Ni) point clearly to the neutral dithiolene-like charge distribution. These complexes [M(ddbt)] have the same chemical compositions as the starting complexes [M(phbt)(2)], and both can be correlated in a new valence isomerism. Crystal data: [Co(ddbt)], monoclinic, P2(1)/n, a = 8.573(2); b = 24.486(3); c = 10.771(1) Angstrom; beta = 102.08(2)degrees; V = 2211.0(9) Angstrom(3); Z = 4, R = 0.056 (R-w = 0.048); [Ni(ddbt)], monoclinic, P2(1)/n,a = 8.631(10); b = 24.365(19); c = 10.798(4) Angstrom; beta = 102.69(6)degrees; V = 2215.2(33) Angstrom(3); Z = 4, R = 0.078 (R-w = 0.075).