A copper(II) complex, 1 of a β-diketiminate ligand {L = (4-(2,6-dimethylphenylimino)pentane-2ylidene)-2,6-dimethylbenzeneamine} has been synthesized and characterized. Single crystal X-ray structure reveals the presence of a mononuclear copper(II) unit with a distorted square planar geometry. In acetonitrile solution of the complex, the β-diketiminate ligand undergoes oxidative degradation to the corresponding ketone diimine under aerobic condition. Addition of nitric oxide to the acetonitrile solution of complex 1 affords the corresponding oxime diimine ligand. All the modified ligands have been isolated and characterized.