Cation supported self-assembly of coordination polymers, [(H2en)(ntpMCl2)]n (MÂ =Â ZnII, CdII, HgII) involving the tripodal acid, ntp: X-ray crystal structure and DNA binding studies on zinc helicate

A first report on the self-assembly of novel coordination polymers of the type, [(H2en)(ntpMCl2)]n [M = ZnII, CdII, HgII] resulting due to deprotonation of ntp, present as the zwitterion [NH+(CH2CH2COOH)2(CH2CH2COO)−] in aqueous medium, by en leading to the formation of the ditopic anion ntp2−, suggesting that H2en2+ acts as a cation template. The coordination polymers thus resulted involve [ntpMCl2]2− as building units stabilized via hydrogen bonding interactions. X-ray analyses on [(H2en)(ntpZnCl2)]n features four coordinate Zn2+ defined by two oxygen donors from ntp2− ligands and two chloride anions.