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Updated: Apr 3, 2026

One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates
Published on: January 15, 2018
Acetic acid dimers in a nitrogen matrix: Observation of structures containing the higher-energy conformer
Susy Lopes1, Alexandra V Domanskaya2, Markku Räsänen3
1Department of Chemistry, University of Coimbra, Rua Larga, P-3004-535 Coimbra, Portugal.
Abstract:
Acetic acid (AA) dimers are studied experimentally by infrared spectroscopy in a N2 matrix and theoretically at the MP2/6-311++G(2d,2p) level of approximation. This work is focused on the first preparation and characterization of structures containing the higher-energy (cis) conformer of AA. Nine trans-trans, fourteen trans-cis, and six cis-cis dimers are theoretically predicted. Five trans-trans and a number of trans-cis dimers are identified in the experiments, but no indication of cis-cis dimers is found. Two trans-trans dimers and the trans-cis dimers are reported for the first time. One trans-cis dimer is prepared by selective vibrational excitation of the structurally related trans-trans dimer, which converts one of the trans subunits to the cis form. Several trans-cis dimers are obtained by annealing of a matrix containing both trans and cis monomers of AA. Tunneling-induced conversion of the trans-cis dimers into trans-trans forms (including two new trans-trans forms) is observed at low temperatures.
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