Influence of pH values on the self-assembly in three trinuclear nickel complexes with bridging ligand N-salicylyl 4-phenyl-thiosemicarbazide

Three trinuclear nickel complexes containing N-salicylyl 4-phenyl-thiosemicarbazide(abbreviated as Spt(3-)) have been synthesized. They are complex [Ni-3(SPt)(2)(dPt)(2)]center dot 2C(3)H(7)NO (1) with 2,5-diphenylamiyl 1,3,4 thiodiazone ligand(dpt) and the other two complexes without dpt ligand ([Ni-3(SPt)(2)(H2O)(4)]center dot 2C(3)H(7)NO (2) and [Ni-3(SPt)(2)(C5H5N)(2)(H2O)(2)]center dot 2C(3)H(7)NO (3)). Central Ni atom and two terminal Ni atoms in the three complexes are combined by two bridging deprotonated spt(3-) ligands, forming a strictly linear trinuclear nickel structure unit with a Ni-N-N-Ni-N-N-Ni core. There is an extended ID structure in 2 and 3 formed by intermolecular hydrogen bonds O-H center dot center dot center dot O. The influence of pH of the reaction medium upon the composition of the final products is discussed. (c) 2007 Elsevier B.V. All rights reserved.