title: Interaction of aromatic compounds with xenon: spectroscopic and computational characterization for the cases of p-cresol and toluene.
abstract: We have investigated noncovalent interactions of two aromatic compounds (toluene and p-cresol) with Xe atoms by using infrared spectroscopy in a Ne matrix and quantum chemical calculations. The present results show that the methyl group of these molecules is a sensitive probe of the interaction with Xe. We have used the molecules with the deuterated methyl group, possessing a relatively simple spectrum, which allows us to detect characteristic vibrational shifts in the complexes, in which a Xe atom interacts with the aromatic π electron system (π structure). For the p-cresol···Xe complex, we also observed evidence of the 1:1 H-bonded structure. The amount of the H-bonded structure of the cresol···Xe complex is relatively small, which agrees with the calculated interaction energies (stronger interaction for the π structure). The bands of the 1:1 complexes of p-cresol and toluene with Xe appear at low Xe concentration and their intensities relative to the monomer bands are nearly proportional to the Xe/Ne concentration ratio. For the p-cresol-Xe system, additional OH stretching bands appear at higher Xe concentrations, which are suitable for the complexes with several Xe atoms. The π structures studied in this work can probably be formed in the case of aromatic amino acids, for which these simple aromatic compounds are useful models.
authors.affiliation: †Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki FI-00014, Finland.|‡School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Cao
authors.affiliation: §Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia.
authors.forename: Natalya
authors.initials: N
authors.lastname: Andrijchenko
authors.affiliation: §Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia.
authors.forename: Alexander
authors.initials: A
authors.lastname: Ermilov
authors.affiliation: †Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki FI-00014, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Räsänen
authors.affiliation: §Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia.
authors.forename: Alexander
authors.initials: A
authors.lastname: Nemukhin
authors.affiliation: †Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki FI-00014, Finland.
authors.forename: Leonid
authors.initials: L
authors.lastname: Khriachtchev
mesh_terms: D003408:Cresols / Q000737:chemistry*; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D014050:Toluene / Q000737:chemistry*; D014978:Xenon / Q000737:chemistry*
chemical_list: D003408:Cresols; C032538:4-cresol; D014050:Toluene; D014978:Xenon