title: A DFT study on proton transfers in hydrolysis reactions of phosphate dianion and sulfate monoanion.
abstract: B3LYP calculations were carried out on hydrolysis reactions of monosubstituted(R) phosphate dianion and sulfate monoanion. In the reacting system, water clusters (H2O)22 and (H2O)35 are included to trace reaction paths. For both P and S substrates with R = methyl group, elementary processes were calculated. While the phosphate undergoes the substitution at the phosphorus, the sulfate does at the methyl carbon. For the S substrate with R = neopentyl group, the product tert-amyl alcohol was found to be formed via a dyotropic rearrangement from the neopentyl alcohol intermediate. For R = aryl groups, transition-state geometries were calculated to be similar between P and S substrates. Calculated activation energies are in good agreement with experimental values. After the rate-determining transition state of the substitution, the hydronium ion H3O(+) is formed at the third water molecule. It was suggested that alkyl and aryl substrates are of the different reactivity of the hydrolysis.
authors.affiliation: Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-Nishihiraki-cho 34-4, Sakyo-ku, Kyoto, 606-8103, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yamabe
authors.forename: Guixiang
authors.initials: G
authors.lastname: Zeng
authors.forename: Wei
authors.initials: W
authors.lastname: Guan
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Sakaki
mesh_terms: D000838:Anions / Q000737:chemistry; D006868:Hydrolysis; D015394:Molecular Structure; D010710:Phosphates / Q000737:chemistry*; D011522:Protons; D011789:Quantum Theory; D013431:Sulfates / Q000737:chemistry*
chemical_list: D000838:Anions; D010710:Phosphates; D011522:Protons; D013431:Sulfates
keywords: hydrolysis reaction; phosphate diation; proton transfer; sulfate monoanion; theoretical calculation