title: An integrated experimental and theoretical investigation of the vibrational modes and molecular structure of a chelate, tetraaqua cysteine aluminum(III).
abstract: The complex formed by Al(3+) and cysteine in aqueous solution has been studied by potentiometry, Raman spectroscopy and DFT calculations (DFT:B3LYP/6-311++G(∗∗)). Atomic charges, frontier molecular orbitals, electrostatic potential contour surface, electrostatic potential map and donor-acceptor second order perturbative energies were examined. The [Al(Cys)(H2O)4](2+) complex adopts a distorted octahedral geometry. Cysteine should act as a bidentate ligand through the oxygen of the carboxylate and the nitrogen of the amino group. The molecule has high HOMO-LUMO energy gap, intense intramolecular charge transfer and positive electrostatic potential.
authors.affiliation: Department of Chemistry, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente, 225, Edifício Cardeal Leme, 7° andar, sala 772A, 22453-900, Rio de Janeiro, RJ, Brazil. Electronic address: tenoriocalc@gmail.com.
authors.forename: Thaís
authors.initials: T
authors.lastname: Tenório
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro, Rua Senador Furtado, 121 a 125, 20270-021, Rio de Janeiro, RJ, Brazil. Electronic address: tenorioifrj@gmail.com.
authors.forename: André
authors.initials: A
authors.lastname: Tenório
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008024:Ligands; D008968:Molecular Conformation; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D011199:Potentiometry; D011789:Quantum Theory; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D014732:Vibration; D014867:Water / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D008024:Ligands; D014867:Water; D000535:Aluminum; D003545:Cysteine; D009584:Nitrogen; D010100:Oxygen
keywords: Aluminum(III); Coordination mode; Cysteine; Geometric arrangement; Vibrational assignments