Molecular geometry as a source of chemical information. 5. Substituent effect on proton transfer in para-substituted phenol complexes with fluoride--a B3LYP/6-311+G study
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Updated: Aug 17, 2026

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Tadeusz M Krygowski1, Halina Szatyłowicz, Joanna E Zachara
1Department of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland.
Abstract:
The simplified model system [p-X-PhO...H...F](-), where -X are -NO, -NO(2), -CHO, -H, -CH(3), -OCH(3), and -OH, with various O...F distance was used to simulate the wide range of the H-bond strength. Structural changes due to variation of the substituent as well as the H-bond strength are well monitored by the changes in the aromaticity index HOMA and by two empirical measures of the H-bond strength-the (1)H NMR chemical shift of proton involved and the C-O bond length. Changes in H-bonding strengths and the position of proton transfer while shortening the O...F distance are well described by the Hammett equation.
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