RESTRICTED ROTATION IN ARYLALKYLKETONES

Author Institution:Molecular orbital calculations using the Partial Retention of Diatomic Differential Overlap Method are presented for a number of arylalkylketones substituted at the ortho and/or para position by hydroxyl groups. Barriers to rotation about the carbonyl to phenyl carbon bond are computed and compared with activation parameters obtained from full lineshape analyses of exchange-broadened NMR spectra. Contributions from steric, mesomeric and hydrogen bonding effects are discussed