title: Solvation-induced σ-complex structure formation in the gas phase: a revisit to the infrared spectroscopy of [C6H6-(CH3OH)2]+.
abstract: Structures of the [C(6)H(6)-(CH(3)OH)(2)](+) cluster cation are investigated with infrared (IR) spectroscopy. While the noncovalent type structure has been confirmed for the n = 1 cluster of [C(6)H(6)-(CH(3)OH)(n)](+), only contradictory interpretations have been given for the spectra of n = 2, in which significant changes have been observed with the Ar tagging. In the present study, we revisit IR spectroscopy of the n = 2 cluster from the viewpoint of the σ-complex structure, which includes a covalent bond formation between the benzene and methanol moieties. The observed spectral range is extended to the lower-frequency region, and the spectrum is measured with and without Ar and N(2) tagging. A strongly hydrogen-bonded OH stretch band, which is characteristic to the σ-complex structure, is newly found with the tagging. The remarkable spectral changes with the tagging are interpreted by the competition between the σ-complex and noncovalent complex structures in the [C(6)H(6)-(CH(3)OH)(2)](+) system. This result shows that the microsolvation only with one methanol molecule can induce the σ-complex structure formation.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Mizuse
authors.forename: Yuta
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Naohiko
authors.initials: N
authors.lastname: Mikami
authors.forename: Asuka
authors.initials: A
authors.lastname: Fujii
mesh_terms: D001554:Benzene / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D000432:Methanol / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011789:Quantum Theory; D012995:Solubility; D013055:Spectrophotometry, Infrared
chemical_list: D005740:Gases; D001554:Benzene; D000432:Methanol