Syntheses and structural studies of cobalt(II), nickel(II), zinc(II) and cadmium(II) selenocyanate complexes with a tetradentate N4-donor ligand

Abstract Four new selenocyanate containing mononuclear complexes of the types [M(NCSe)(dbdmp)]ClO 4 [M = Co(II), Zn(II)], [Ni(dbdmp)(NCSe) 2 ] and [Cd(dbdmp)(SeCN) 2 ] where dbdmp =  N , N -diethyl- N ′, N ′-bis((3,5-dimethyl- 1H -pyrazol-1-yl)methyl)ethane-1,2-diamine have been synthesized and characterized by microanalysis, physico-chemical and spectroscopic methods. The crystal structures of the four complexes [Co(NCSe)(dbdmp)]ClO 4 ( 1 ) [Ni(dbdmp)(NCSe) 2 ] ( 2 ), [Zn(NCSe)(dbdmp)]ClO 4 ( 3 ) and [Cd(dbdmp)(SeCN) 2 ] ( 4 ) have been solved by single crystal X-ray diffraction studies and they showed that complexes 1 and 3 have a distorted trigonal bipyramidal geometry, whereas complexes 2 and 4 have a distorted octahedral geometry and the ligand dbdmp shows two different isomers in the complexes 2 and 4 . In complex 4 , the selenium atom is bonded to the cadmium(II) center, whereas the nitrogen atom of the selenocyanate ion is coordinated to Co(II), Ni(II) and Zn(II) centers in 1 – 3 .