Synthesis and characterization of 16-membered octaaza macrocyclic Ni (II) complexes

Author Name : Rajeev Kumar Singh

ABSTRACT

                A series of Ni (II) complexes with a tetradentate nitrogen donor octaazamacrocyclic ligand was synthesized. On the basis of elemental analysis , the formula of the complex was derived and found to be of the type [Ni(L)]X 2 (Where L=1, 4, 5, 8, 9, 12, 13, 16 – octaaza - 2,3,6,7,10,11,14,15, - octamethyl - cyclohexadeca- 1,3,5,7,9,11,13,15 - octaene, X= Cl - , Ac - which was obtained by the metal ion catalyzed template Schiff base condensation of diacetyl with hydrazine ) The molar conductance value of the Ni (II) complex in acetonitrile was 202 S cm 2 mol -1 , indicating a 1:2 electrolytic nature. The complex was found to be diamagnetic. Based on spectral studies, square planar geometry was proposed. Infrared spectra suggest co-ordination to take place with four of the eight azomethinic nitrogen donor atoms. Nitrogen atoms giving rise to 5:7:5:7 system of chelate ring.

Keywords: Octaazamacrocyclic ligand, Ni (II) complex, characterization.