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Predicting the reactivity of phenolic compounds with formaldehyde under basic conditions: An ab initio study
Author(s) -
Conner Anthony H.
Publication year - 2000
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/1097-4628(20001010)78:2<355::aid-app150>3.0.co;2-3
Subject(s) - reactivity (psychology) , chemistry , formaldehyde , steric effects , ab initio , computational chemistry , substituent , reaction rate constant , molecular orbital , organic chemistry , molecule , kinetics , medicine , alternative medicine , pathology , physics , quantum mechanics
A method is needed to predict which compounds, from the many alternative phenolic compounds, might be best for making polymeric phenolic systems. Kinetic data for the reaction of a series of phenolic compounds with formaldehyde using a base catalysis are available in the literature. Semiempirical calculations, using RHF/PM3, and ab initio calculations, using RHF/6‐31G, RHF/6‐31+G, and B3LYP/6‐311+G(2d,p), were performed on the series of phenolic compounds to determine their relative reactivities. Atomic charges were determined for the phenolate anions. For each compound, I summed the absolute value of the calculated, negative charges residing on carbon atoms of the phenolic ring at which the HOMO was located and at which no substituent was present to cause steric interference with the reaction. The sum of the charges for each compound was then regressed against the log of the relative reaction rate for that compound. The sum of charges from PM3‐based calculations gave poor correlation with reactivity. The sums of charges calculated by the CHelpG and Merz–Kollman/Singh methods at the ab initio levels of theory give excellent correlations with reactivity of the phenolics toward formaldehyde. Based on the calculated charges, estimates of the relative reactivity at each of the reactive sites on each of the phenolic compounds were determined. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 355–363, 2000