Accurate torsional potentials for monohalo and fluorohalo keto-enolate compounds

• Published in: International journal of quantum chemistry Vol. 109; no. 10; pp. 2199 - 2207
• Main Authors: Vongachariya, Arthit, Tantiwattanakul, Sutheera, Parasuk, Vudhichai
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 2009
• Subjects: CBS; CCSD(T); keto-enolate; torsional potential
• ISSN: 0020-7608; 1097-461X
• DOI: 10.1002/qua.22113

Accurate torsional potentials upon two rotatable carbon–carbon bonds for monohalo and fluorohalo keto‐enolate compounds were constructed using CCSD(T)/CBS level of theory. Stable conformers of monohalo and fluorohalo keto‐enolates can be determined from the steric repulsion between moieties around these carbon–carbon bonds. The repulsion between fluorine and halogen atoms is the strongest and stronger than that between oxygen and halogen, followed by that between oxygen and oxygen. The maximum of the torsional potentials corresponds to the conformation where both or one of the two rotatable bonds align perpendicular to the molecular plane, suggesting the strong double bond character between these two carbon–carbon bonds. Thus, the π‐bond conjugation and steric repulsion control the torsional potentials of monohalo and fluorohalo keto‐enolate compounds. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009