Deprotonation of solvated formic acid: Car-Parrinello and Metadynamics simulations

JUNG-GOO LEE; ELIANA ASCIUTTO; VOLODYMYR BABIN; CELESTE SAGUI; THOMAS DARDEN; CHRISTOPHER ROLAND

JOURNAL OF PHYSICAL CHEMISTRY B - (Print)

AMER CHEMICAL SOC

Año: 2006 vol. 110 p. 2325 - 2331

1520-6106

AbstractThe deprotonation of solvated formic acid was investigated theoretically with ab initio simulations. With the Car-Parrinello method, deprotonation and reprotonation by means of a proton wire were observed. Themicroscopics of these reactions were analyzed, and reveal the key role played by nearby water molecules in catalyzing the reactions. A constrained molecular dynamics calculation was carried out to estimate the dissociation free energy. Deprotonation of formic acid was further investigated with the recently developed metadynamics method using the formic acid oxygen coordination numbers as the collective variables. Thedetermined free-energy landscape gives barriers similar to that obtained with the constrained free-energy calculation.