Nickel(II) complexes of novel tetraaza macrocyclic ligands bearing pendant donor groups

Abstract

The addition of nitromethanide to two less hindered CN double bonds of polyalkyl-1,4,8,11 -tetraazacyclotetradeca-1,4,8,11-tetraenenickel(II) diperchlorate complexes, 1, gave nickel(II) complexes, 2, of novel macrocyclic ligands containing two co-ordinated, pendant aci-nitromethyl groups. Reduction of the nitro groups leads to 2,9-bis(aminomethyl) substituted nickel(II) complexes 5. High-spin complexes 2 and 5(pendant groups co-ordinated) and their corresponding low-spin protonated derivatives 3 and 6(pendant groups unco-ordinated) have been prepared and characterised.