Transition metal complexes with thiosemicarbazide-based ligands. Part 51. Square-planer nickel(II)complex with acetylacetone bis(S-n-propylisothiosemicarbazone)(L).Crystal and molecular structure of [

The template reaction of a warm methanolic solution of Ni(OAc)2?4H2O S-n-propylisothiosemicarbazide hydroiodide and acetylacetone yielded the needle- like, brown, diamagnetic complex [Ni(L-H)]I?MeOH, and in the presence of an excess of NH 4NCS, brown, prismatic crystals of the complex [Ni(L-H)]NCS (1), both compounds involving the monoanionic form of the ligand, acetylacetone bis(S-n-propylisothiosemicarbazone), L. Slow recrystallization fromMeOH, EtOH, iPrOH and Me2CO gave the corresponding monosolvent complexes [Ni(L-H)]I?solvent, of which only those involving EtOH and iPrOH were suitable for structural analysis. The crystallographic parameters of [Ni(L-H)]I?EtOH (2) and [Ni(L-H)]I?iPrOH (3) are very similar to each other, showing their structures are isomorphic. The crystal structures of the title compounds consist of the independent ions: NCS-, or I-, and the chemically identical cation [Ni(L-H)]+, where L-H is the monoanion resulting from deprotonation of the acetylacetone moiety, a tetradentate N4 ligand forming a square-planar coordination around a Ni(II) ion. It was found that the isothiosemicarbazide fragment of the ligand has an imido form. The complex cations of the compounds [Ni(L-H)]NCS and [Ni(L-H)]I?EtOH exhibit significant difference only in the conformation of their propyl groups.