Ab initio molecular dynamics study of H-bonding and proton transfer in the phosphoric acid-N,N-Dimethylformamide system

Авторы публикации: 
Irina V. Fedorova, Michael A. Krestyaninov,•Lyubov P. Safonova
The Journal of Chemical Physics
Год публикации: 
V. 145, P. 124507(7)

Car-Parrinello molecular dynamics simulations of phosphoric acid (H3PO4)-N,N-dimethylformamide (DMF) mixtures over the whole composition range have been carried out. It has been found that the neutral molecules are the dominant species in this system. The concentration dependences of the average number of H-bonds per proton acceptor atom in P=O and C=O groups as well as per proton donor atom in DMFH+ ions towards phosphate species have been discussed. The H-bonding between components in all investigated mixtures of H3PO4 and DMF is possible. A significant fraction of the protonated DMF forms appears at phosphoric acid mole fraction higher than 0.37, indicating a high probability of proton transfer from phosphate species to oxygen atoms in C=O groups. The intermolecular proton transfer between phosphate species themselves is mainly observed when x(H3PO4) > 0.19. Satisfactory agreement with available experimental data for structural characteristics of the investigated system was obtained.

Колкер Аркадий Михайлович