Details of the syntheses and the results of X-ray structural analyses of square planar Ni compounds with aliphatic thiolato-sulfur ligands, [Ni(dpmep)(2)] (1) and [Ni(tpttd)] (2), where Hdmep and H(2)tpttd are the abbreviations for 2-(2,2-diphenyl-2-mercaptoethyl)pyridine and 2,2',11,11'-tetraphenyl-1,5,8,12-tetrathiadodecane respectively, are presented. Each of the thiolato-sulfur atoms of these compounds is sterically protected by two benzene rings at the alpha carbon position to suppress dimerization upon synthesis. 1.1.5Ch(2)Cl(2) . MeCN crystallizes monoclinic P2(1)/n with a = 18.362(3), b = 16.894(4), c = 13.273(4) Angstrom, beta = 104.59(2)degrees, V = 3984(3) Angstrom(3) and Z = 4.2.1.5MeCN crystallizes triclinic
with a = 15.091(6), b = 15.661(3), c = 14.085(7) Angstrom, alpha = 96.00(2), beta = 90.89(4), gamma = 99.70(2)degrees, V = 32.61(4) Angstrom(3) and Z = 4. The Ni-S and Ni-N bond lengths of 1 were compared with those of the nickel center in the A-cluster of carbon monoxide dehydrogenase. (C) 1997 Elsevier Science S.A.