title: UV and IR Spectroscopy of Cryogenically Cooled, Lanthanide-Containing Ions in the Gas Phase.
abstract: We measure UV and IR spectra in the gas phase for EuOH+, EuCl+, and TbO+ions, which are produced by an electrospray ionization source and cooled to ∼10 K in a cold, 22-pole ion trap. The UV photodissociation (UVPD) spectra of these ions show a number of sharp, well-resolved bands in the 30000-38000 cm-1region, although a definite assignment of the spectra is difficult because of a high degree of congestion. We also measure an IR spectrum of the EuOH+ion in the 3500-3800 cm-1region by IR-UV double-resonance spectroscopy, which reveals an OH stretching band at 3732 cm-1. We perform density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations of these ions in order to examine the nature of the transitions. The DFT results indicate that the states of highest-spin multiplicity (octet for EuOH+and EuCl+and septet for TbO+) are substantially more stable than other states of lower-spin multiplicity. The TD-DFT calculations suggest that UV absorption of the EuOH+and EuCl+ions arises from Eu(4f) → Eu(5d,6p) transitions, whereas electronic transitions of the TbO+ion are mainly due to the electron promotion of O(2p) → Tb(4f,6s). The UVPD results of the lanthanide-containing ions in this study suggest the possibility of using lanthanide ions as "conformation reporters" for gas-phase spectroscopy for large molecules.
authors.affiliation: Department of Chemistry, Graduate School of Science, Hiroshima University , Higashi-Hiroshima, Hiroshima 739-8526, Japan.
authors.forename: Yoshiya
authors.identifier: http://orcid.org/0000-0001-7959-5315
authors.initials: Y
authors.lastname: Inokuchi
authors.affiliation: Department of Chemistry, Graduate School of Science, Hiroshima University , Higashi-Hiroshima, Hiroshima 739-8526, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kaneko
authors.affiliation: Department of Chemistry, Graduate School of Science, Hiroshima University , Higashi-Hiroshima, Hiroshima 739-8526, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Honda
authors.affiliation: Department of Chemistry, Graduate School of Science, Hiroshima University , Higashi-Hiroshima, Hiroshima 739-8526, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Nakashima
authors.affiliation: Department of Chemistry, Graduate School of Science, Hiroshima University , Higashi-Hiroshima, Hiroshima 739-8526, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ebata
authors.affiliation: Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne , Lausanne CH-1015, Switzerland.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Rizzo