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RESEARCH PRODUCT
The internal rotational barrier of biphenyl studied with multiconfigurational second-order perturbation theory (CASPT2)
Enrique OrtíMercedes RubioManuela Merchánsubject
BiphenylChemistryPerturbation (astronomy)Molecular physicschemistry.chemical_compoundMolecular geometryElectron diffractionComputational chemistryPerpendicularMoleculeChiropracticsPhysical and Theoretical ChemistryWave functionConformational isomerismdescription
A detailedab initio study of the molecular structure and rotational barriers of biphenyl has been performed. First, non-dynamical correlation effects involving the π system are taken into account at the CASSCF level. These wave functions are subsequently employed as reference functions in a multiconfigurational second-order perturbation treatment (CASPT2). The performance single-reference approaches is in addition analysed. The molecular geometries of biphenyl in twisted, coplanar, and perpendicular conformations have been optimized at the CASSCF level. A rotational angle of 44.3° is predicted for the minimum energy conformer in agreement with gas-phase electron diffraction data (44.4±1.2°). The highest level of theory employed yields the values 12.93 (6.0±2.1) and 6.40 (6.5±2.5) kJ/mol for the barrier heights at 0° and 90°, respectively (electron diffraction data within parentheses). In the light of the present findings, the reliability of the available experimental data is discussed.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1995-04-01 | Theoretica Chimica Acta |