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Updated: Jun 16, 2026

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Matrix isolation and ab initio study of trans-trans and trans-cis dimers of formic acid
Kseniya Marushkevich1, Leonid Khriachtchev, Jan Lundell
1Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland.
Abstract:
Six trans-trans and five trans-cis dimeric structures of formic acid (HCOOH) are revealed by ab initio calculations. Four trans-trans and two trans-cis dimers are identified in the IR absorption spectra in argon matrices. The trans-cis dimers are obtained by narrow-band IR excitation of the vibrational transitions of the trans-trans dimers. Two trans-trans (tt3 and tt6) and one trans-cis (tc4) dimer are characterized experimentally for the first time. The tunneling decay rates of two trans-cis dimers (tc1 and tc4) are evaluated at different temperatures. A greater lifetime of the trans-cis dimers at elevated temperatures compared to the cis-monomer suggests that the high-energy conformers can be stabilized upon hydrogen bonding.
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