title: Computer simulation study of the intermolecular structure of phosphoric acid-N,N-dimethylformamide mixtures.
abstract: The structures and energies of the complexes (H3PO4)2, H3PO4-DMF, and (H3PO4)2-DMF were analyzed at the B3LYP level of approximation. It was found that H-bonds form between H3PO4 and DMF molecules, but the strength of the H-bond depends strongly on its molecular environment. Effects of the solvent were taken into account via the CPCM approach. According to the B3LYP-СPCM calculations, the O···O distance in (H3PO4)2-DMF is shorter and its H-bonds are stronger than in the other complexes studied. In order to study the effects of concentration on the intermolecular structure, molecular dynamics simulations of H3PO4-DMF mixtures with mole fractions of acid of <0.1 were performed. The calculations indicated that the largest fraction of the acid protons are involved in hydrogen bonding with oxygen atoms of the DMF molecules. An increased probability of acid-acid hydrogen-bond formation at phosphoric acid mole fractions >0.06 was also noted.
authors.affiliation: G. A. Krestov Institute of Solution Chemistry of Russian Academy of Sciences, 1 Akademicheskaya Street, Ivanovo, 153045, Russia, fiv_ira@mail.ru.
authors.forename: Irina V
authors.initials: IV
authors.lastname: Fedorova
authors.forename: Michael G
authors.initials: MG
authors.lastname: Kiselev
authors.forename: Lyubov P
authors.initials: LP
authors.lastname: Safonova
mesh_terms: D004126:Dimethylformamide / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D010756:Phosphoric Acids / Q000737:chemistry*
chemical_list: D010756:Phosphoric Acids; D004126:Dimethylformamide; C030242:phosphoric acid