title: Density-functional theory study of Iron(III) hydrolysis in aqueous solution.
abstract: Fe(III) hydrolysis in aqueous solution has been investigated using density-functional methods (DFT). All possible structures arising from different tautomers and multiplicities have been calculated. The solvation energy has been estimated using the UAHF-PCM method. The hydrolysis free energies have been estimated and compared with the available experimental data. The different hydrolysis species have distinct geometries and electronic structures. We have shown that improvement of theory level in calculating the electronic energy does not necessarily improve the estimated free energies in aqueous solution since the UAHF-PCM is a simple method that neglects specific interactions with the solvent. Therefore, it is important to have the correct balance between theory level used in the electronic calculation and the UAHF-PCM. The PBE/TZVP/UAHF-PCM method has been found to describe correctly the hydrolysis energies of Fe(III), deviating about 3.0 kcal mol(-1) from experimental values.
authors.affiliation: Grupo de Pesquisa em Química Inorgânica Teórica, Departamento de Química, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, MG, 31.270-901, Brazil.
authors.forename: Heitor Avelino
authors.initials: HA
authors.lastname: De Abreu
authors.forename: Luciana
authors.initials: L
authors.lastname: Guimarães
authors.forename: Hélio Anderson
authors.initials: HA
authors.lastname: Duarte
mesh_terms: D003198:Computer Simulation; D019281:Dimerization; D004735:Energy Transfer; D006868:Hydrolysis; D007501:Iron / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D012997:Solvents; D014867:Water
chemical_list: D012997:Solvents; D014867:Water; D007501:Iron