title: Effect of formic acid addition on water cluster stability and structure.
abstract: Computational chemistry simulations were performed to determine the effect that the addition of a single formic acid molecule has on the structure and stability of protonated water clusters. Previous experimental studies showed that addition of formic acid to protonated pure water results in higher intensities of large-sized clusters when compared to pure water and methanol-water mixed clusters. For larger, protonated clusters, molecular dynamics simulations were performed on H(+)(H(2)O)(n), H(+)(H(2)O)(n)CH(3)OH, and H(+)(H(2)O)(n)CHOOH clusters, 19-28 molecules in size, using a reactive force field (ReaxFF). Based on these computations, formic acid-water clusters were found to have significantly higher binding energies per molecule. Addition of formic acid to a water cluster was found to alter the structure of the hydrogen-bonding network, creating selective sites within the cluster, enabling the formation of new hydrogen bonds, and increasing both the stability of the cluster and its rate of growth.
authors.affiliation: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
authors.forename: Erin G
authors.initials: EG
authors.lastname: Goken
authors.forename: Kaushik L
authors.initials: KL
authors.lastname: Joshi
authors.forename: Michael F
authors.initials: MF
authors.lastname: Russo
authors.forename: Adri C T
authors.initials: AC
authors.lastname: van Duin
authors.forename: A W
authors.initials: AW
authors.lastname: Castleman
mesh_terms: D005561:Formates / Q000737:chemistry*; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D014867:Water / Q000737:chemistry*
chemical_list: D005561:Formates; D014867:Water; C030544:formic acid