Correlations between i.r. frequencies and substituent constants—I. General considerations and aliphatic compounds

Abstract

Consideration is given to the vast number of correlations reported in the literature between i.r. frequency shifts and substituent constants and criteria are proposed as a basis for establishing which data are satisfactory for this purpose. The data available for aliphatic compounds is analysed both against inductive constants alone and against a combination of inductive and resonance parameters. A limited number of series show good correlation against inductive parameters and the inclusion of resonance parameters markedly improves the correlation in some further series.