Cyclic voltammetric studies of axially substituted nickel(II) complexes containing a macrocyclic Schiff-base ligand

The ligand L, prepared by template condensation of bis-6,6 "-(alpha-methylh ydrazino)-4/-phenyl-2,2':6 "',2'-terpyridine with glyoxal, forms a stable c rystalline complex of nickel(II)[Ni(L)(H2O)(2)][PF6](2) which is used as a starting material for cyclic voltammetric studies of a series of seven-coor dinate nickel(II) complexes [Ni(L)X-2](2+) (X = 4-substituted pyridines, im idazole, 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, pyraz ine, thiazole, triphenylphosphite, dimethylsulfoxide and dabco), Cyclic vol tammetry of the complexes in acetonitrile shows a reversible one-electron r eduction wave in the range of -1.08 to -1.46 V vs a Ag/AgBF4 reference elec trode.