Spectroscopic characterizations and biological studies on newly synthesized Cu 2+ and Zn 2+ complexes of first and second generation dendrimers

Abstract

The novel Cu(II) and Zn(II) complexes of first and second generation poly(propylene amine) dendrimers (PPA), comprising 1,8-naphthalimde units on periphery have been synthesized. These new complexes were characterized by elemental analysis, molar conductivity, spectral methods (IR, 1H NMR and UV–vis spectra) and thermal analysis (TG and DTG) techniques. From elemental analysis as well as thermal studies it has found that the first generation dendrimer behaves as bidentate ligand and forming chelates with 1:2 (ligand:metal) and 1:4 (ligand:metal) stoichiometry for second generation dendrimer. Different kinetic parameters namely activation energy (Δ E*), enthalpy of activation (Δ H*), entropy of activation (Δ S*) and free energy change of activation (Δ G*) are calculated using Coats–Redfern equation. The antibacterial activity of dendrimers and their complexes was evaluated against some Gram positive and negative bacteria.