title: Structural characterization of electron-induced proton transfer in the formic acid dimer anion, (HCOOH)2-, with vibrational and photoelectron spectroscopies.
abstract: The (HCOOH)(2) anion, formed by electron attachment to the formic acid dimer (FA(2)), is an archetypal system for exploring the mechanics of the electron-induced proton transfer motif that is purported to occur when neutral nucleic acid base-pairs accommodate an excess electron [K. Aflatooni, G. A. Gallup, and P. D. Burrow, J. Phys. Chem. A 102, 6205 (1998); J. H. Hendricks, S. A. Lyapustina, H. L. de Clercq, J. T. Snodgrass, and K. H. Bowen, J. Chem Phys. 104, 7788 (1996); C. Desfrancois, H. Abdoul-Carime, and J. P. Schermann, ibid. 104, 7792 (1996)]. The FA(2) anion and several of its H∕D isotopologues were isolated in the gas phase and characterized using Ar-tagged vibrational predissociation and electron autodetachment spectroscopies. The photoelectron spectrum of the FA(2) anion was also recorded using velocity-map imaging. The resulting spectroscopic information verifies the equilibrium FA(2)(-) geometry predicted by theory which features a symmetrical, double H-bonded bridge effectively linking together constituents that most closely resemble the formate ion and a dihydroxymethyl radical. The spectroscopic signatures of this ion were analyzed with the aid of calculated anharmonic vibrational band patterns.
authors.affiliation: Sterling Chemistry Laboratory, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, USA.
authors.forename: Helen K
authors.initials: HK
authors.lastname: Gerardi
authors.forename: Andrew F
authors.initials: AF
authors.lastname: DeBlase
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Leavitt
authors.forename: Xiaoge
authors.initials: X
authors.lastname: Su
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Jordan
authors.forename: Anne B
authors.initials: AB
authors.lastname: McCoy
authors.forename: Mark A
authors.initials: MA
authors.lastname: Johnson
mesh_terms: D019281:Dimerization; D004583:Electrons; D005561:Formates / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D056951:Photoelectron Spectroscopy; D011522:Protons; D014732:Vibration
chemical_list: D005561:Formates; D011522:Protons; C030544:formic acid