conformational analysis of methylboronic acid and its acyclic esters
O. Y. Valiakhmetova, S. A. Bochkor, V. V. Kuznetsov
Keywords: methylboronic acid, boric ester, conformer, quantum chemical calculations, potential energy surfaces, internal rotation barrier
Pages: 590-592
Abstract
With the use of RHF/6-31G(d) and МР2/6-31G(d)//RHF/6-31G(d) semi-empirical (АМ1) and non-empirical quantum chemical approximations conformational isomerization of methylboronic acid and its methyl, isopropyl, tert-butyl, and phenyl esters is studied. With the exception of the tert-butyl analogue, the potential energy surface of molecules in these compounds, is shown to contain three minima that correspond to planar and near-planar conformers: cis-cis, trans-trans, and cis-trans, with the latter being the main one. The minima are separated by two conformational isomerization barriers corresponding to the orthogonal arrangement of one of the ОН(ОR) groups.
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