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The Conformation of Alkyl Benzyl Alcohols Studied by ab initio MO Calculations − A Comparison with IR and NMR Spectroscopic Data
Author(s) -
Takahashi Osamu,
Saito Ko,
Kohno Yuji,
Suezawa Hiroko,
Ishihara Shinji,
Nishio Motohiro
Publication year - 2004
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200300801
Subject(s) - chemistry , vicinal , alkyl , ab initio , van der waals force , ab initio quantum chemistry methods , hydrogen bond , crystallography , computational chemistry , carbon 13 nmr , stereochemistry , molecule , organic chemistry
Ab initio MO calculations were carried out for the conformations of a series of alkyl‐substituted benzyl alcohols C 6 H 5 CH 2 CHOH−R (R = CH 3 , C 2 H 5 , i Pr, t Bu) at the MP2/6‐311G(d,p)//MP2/6‐31G(d) level. It was found that the conformation where the OH group is gauche to the phenyl group is the most stable. The geometry where both the OH and R groups are close to phenyl is the second most stable. This finding has been interpreted on the grounds of the attractive OH/π and CH/π hydrogen bonds and a repulsive van der Waals interaction between vicinal CH groups. NMR nuclear Overhauser effects, spin‐coupling data, and IR spectroscopic data are consistent with the conclusion given by the MO calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)