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)center dot 4H(2)O, S-n-propylisothiosemicarbazide hydroiodide and acetylacetone yielded the needle-like, brown, diamagnetic complex [Ni(L-H)]I center dot MeOH, and in the presence of an excess of NH4NCS, 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 from MeOH, 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 center dot EtOH (2) and[Ni(L-H)]I center dot 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 N-4 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 center dot EtOH exhibit significant difference only in the conformation of their propyl groups.