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Conformations of Organophosphine Oxides

TitleConformations of Organophosphine Oxides
Publication TypeJournal Article
Year of Publication2015
AuthorsDe Silva, N, Zahariev, F, Hay, BP, Gordon, MS, Windus, TL
JournalJournal of Physical Chemistry A
Date Published08
Type of ArticleArticle
ISBN Number1089-5639
Accession NumberWOS:000359683400021
Keywordsactinides, aqueous-solutions, electron localization function, liquid-membrane, mmff94, molecular-force field, n-dodecane, phosphine oxide, solvent-extraction, structure-based design, supported

The conformations of a series of organophosphine oxides, OP(CH3)(2)R, where R = methyl, ethyl, isopropyl, tert-butyl, vinyl, and phenyl, are predicted using the MP2/cc-pVTZ level of theory. Comparison of potential energy surfaces for rotation about P-C bonds with crystal structure data reveals a strong correlation between predicted location and energetics of minima and histograms of dihedral angle distributions observed in the solid state. In addition, the most stable conformers are those that minimize the extent of steric repulsion between adjacent rotor substituents, and the torsional barriers tend to increase with the steric bulk of the rotating alkyl group. MM3 force field parameters were adjusted to fit the MP2 results, providing a fast and accurate model for predicting organophosphine oxides shapes-an essential part of understanding the chemistry of these compounds. The predictive power of the modified MM3 model was tested against MP2/cc-pVTZ conformations for triethylphosphine oxide, OP(CH2CH3)(3), and triphenylphosphine oxide, OP(Ph)(3).

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