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 spt3−) have been synthesized. They are complex [Ni3(spt)2(dpt)2]·2C3H7NO (1) with 2,5-diphenylamiyl 1,3,4 thiodiazone ligand(dpt) and the other two complexes without dpt ligand ([Ni3(spt)2(H2O)4]·2C3H7NO (2) and [Ni3(spt)2(C5H5N)2(H2O)2]·2C3H7NO (3)). Central Ni atom and two terminal Ni atoms in the three complexes are combined by two bridging deprotonated spt3− ligands, forming a strictly linear trinuclear nickel structure unit with a NiNNNiNNNi core. There is an extended 1D structure in 2 and 3 formed by intermolecular hydrogen bonds OH…O. The influence of pH of the reaction medium upon the composition of the final products is discussed.