Nuclease activity of mixed ligand complexes of copper(II) with heteroaromatic derivatives and picoline

New picoline adducts with carbamic acid (furan-2-yl)methylene]hydrazide–Cu^II (CFMH) (1); thiocarbamic acid (furan-2-yl)methylene]hydrazide–Cu^II (TFMH) (2); carbamic acid (furan-2-yl)ethylidene]hydrazide–Cu^II (CFEH) (3), thiocarbamic acid (furan-2-yl)ethylidene]hydrazide–Cu^II (TFEH) (4); carbamic acid (thiophene-2-yl) methylene]hydrazide–Cu^II (CTMH) (5), thiocarbamic acid (thiophene-2-yl)methylene]hydrazide–Cu^II (TTMH) (6), carbamic acid (thiophene-2-yl)ethylidene]hydrazide–Cu^II (CTEH) (7), thiocarbamic acid (thiophene-2-yl)ethylidene]hydrazide–Cu^II (TTEH) (8) have been prepared and characterized by analytical, i.r., electronic, e.s.r. and c.v. spectral data. The electronic spectra suggest distorted octahedral geometry for all the picoline adducts. E.s.r. g values lie between 2.251–2.286 at l.n.t. All the adducts undergo a quasi-reversible one-electron reduction in the range +0.47 to +0.51 V versus s.c.e., attributable to the Cu^III/Cu^II redox couple. The electron transfer is much faster in the semicarbazone complexes than in the thiosemicarbazone complexes. All adducts showed increased nuclease activity in the presence of oxidant; the nuclease activity is compared with that of the parent copper(II) complexes.