title: Dimers of the higher-energy conformer of formic acid: experimental observation.
abstract: We report on the first experimental observation of formic acid dimers composed of two molecules of the higher-energy cis conformer. The cis-cis formic acid dimers are prepared in an argon matrix by selective vibrational excitation of the ground state trans conformer (deuterated form HCOOD) combined with thermal annealing of the matrix at about 30 K. Five cis-cis formic acid dimers are predicted by ab initio calculations (interaction energies from -16.9 to -27.2 kJ mol(-1)), and these structures are used for the assignment of the experimental spectra. Selective vibrational excitation of the obtained cis-cis dimers leads to the formation of several trans-cis dimers, which supports the proposed assignments.
authors.affiliation: Department of Chemistry, University of Helsinki, Helsinki, Finland.
authors.forename: Kseniya
authors.initials: K
authors.lastname: Marushkevich
authors.forename: Leonid
authors.initials: L
authors.lastname: Khriachtchev
authors.forename: Markku
authors.initials: M
authors.lastname: Räsänen
authors.forename: Mia
authors.initials: M
authors.lastname: Melavuori
authors.forename: Jan
authors.initials: J
authors.lastname: Lundell