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" A Quantum Chemical Investigation of the C-O Bond Length and Stretching Mode of the Phenolate Anion" M. Nonella, H.U. SutterJ. Phys. Chem. 102A, 1998, 10128-10133. Abstract: Structure and vibrational spectrum of the phenolate anion have been calculated with various quantum chemical methods. Correlated methods predict a C-O bond length between 1.28 and 1.29 Å which is significantly shorter than an earlier suggested value of 1.40 Å. This indicates a partial double bond character for the C-O bond in the phenolate anion which is explained in terms of resonance structures. IR frequencies determined with pure density functional methods agree well with FTIR data in the case of the modes n4 and n5 while the frequency of the C-O mode is significantly overestimated in all calculations. The calculations of the isolated phenolate anion do thus poorly agree with experimental data. We demonstrate, that upon complexation of the phenolate anion with a positively charged counter ion the C-O bond is elongated and becomes considerable single bond character. The intermolecular interaction also causes a down shift of 30 cm-1 of the C-O stretching mode and thus reveals a better agreement with experimental data. BMO authors (in alphabetic order): Marco Nonella |