title: Infrared photodissociation spectroscopy of protonated ammonia cluster ions, NH4+(NH3)n (n=5-8), by using infrared free electron laser.
abstract: Infrared photodissociation action spectra of protonated ammonia cluster ions, NH(4) (+)(NH(3))(n) (n=5-8), were measured in the range of 1020-1210 cm(-1) by using a tunable infrared free electron laser. Analyses by the density functional theory (DFT) show that the spectral features observed can be assigned to the nu(2) vibrational mode of the NH(3) molecules in NH(4) (+)(NH(3))(n). Size dependence of the spectra supports structural models obtained by the DFT calculations, in which the NH(4) (+) ion is solvated by the four nearest-neighbor NH(3) molecules. For NH(4) (+)(NH(3))(5), the spectrum between 1000 and 1700 cm(-1) was measured. The nu(4) bands of the NH(3) molecules and the NH(4) (+) ion were found in the range of 1420-1700 cm(-1).
authors.affiliation: Department of Chemistry, School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Tono
authors.forename: Kotatsu
authors.initials: K
authors.lastname: Bito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kondoh
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Ohta
authors.forename: Koichi
authors.initials: K
authors.lastname: Tsukiyama