Synthesis and characterization of Zn(II) and Cd(II) complexes with 2,6-diacetylpyridine-bis(selenosemicarbazone). Crystal structure of a Ni(II) complex with a modified 2,6-diacetylpyridine-bis(selenosemicarbazone)

A novel ligand 2,6-diacetylpyridine-bis(selenosemicarbazone) was synthesized and coordinated with Zn(II), Cd(II) and Ni(II). With Zn(II) and Cd(II), the bideprotonated ligand was coordinated as a quinquedentate in trigonal bipyramidal geometry. With Ni(II) during coordination the ligand was modified by elimination of hydrogen selenide and the product was coordinated as a quadridentate forming a square planar complex, the structure of which was determined by X-ray analysis.