title: Density functional theory studies of Pb (II) interaction with chitosan and its derivatives.
abstract: Density functional theory (DFT) studies of Pb (II) ions interaction with biopolymer chitosan and its derivatives are presented. Schiff bases and N-alkylated/arylated derivatives of chitosan were characterized as adsorbents of lead ions and are studied at monomer level. Natural bond orbital (NBO) analysis was carried out for chitosan and derivatives to understand the donor-acceptor interactions. Molecular electrostatic potential (MEP) maps of the adsorbents were plotted with color code. Global reactivity parameters of adsorbents were calculated on the basis of frontier molecular orbital (FMO) energies. Structure of complexes formed between chitosan and derivatives with Pb (II) ion were examined at B3LYP/LanL2DZ level of DFT. The stability of the complexes are discussed based on the values of Eads. We observed that the N-reduced pyridine carboxaldehyde derivative of chitosan (RPC) forms more stable complex with Pb (II) ions than with other derivatves.
authors.affiliation: Department of Chemistry, University of Calicut, Malappuram, Kerala 673635, India.
authors.forename: Basila
authors.initials: B
authors.lastname: Hassan
authors.affiliation: Department of Chemistry, University of Calicut, Malappuram, Kerala 673635, India. Electronic address: kmuralika@gmail.com.
authors.forename: K
authors.initials: K
authors.lastname: Muraleedharan
authors.affiliation: Department of Chemistry, University of Calicut, Malappuram, Kerala 673635, India. Electronic address: vmamujeeb@gmail.com.
authors.forename: V M
authors.initials: VM
authors.lastname: Abdul Mujeeb
mesh_terms: D048271:Chitosan / Q000031:analogs & derivatives* / Q000737:chemistry*; D020450:Heavy Ions; D007854:Lead / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D007854:Lead; D048271:Chitosan
keywords: Density functional theory; Molecular electrostatic potential maps; Natural bond orbital analysis