CORRELATIONS OF INFRARED GROUP FREQUENCIES AND BAND INTENSITIES IN ORGANIC MOLECULES WITH SUBSTITUENT CONSTANTS: A STATISTICAL EVALUATION

A statistical evaluation of the empirical linear correlations of infrared group frequencies and band intensities in aliphatic and benzene derivatives with substituent constants has been carried out. The correlations of frequencies with substituent constants generally give low standard deviations and acceptable correlation coefficients, and may thus be employed for the estimation of substituent constants. The correlations of band intensities with substituent constants show an interesting trend of the sign and magnitude of the slopes (ρ values) with the electrical property of the bond or group involved in the vibration. The ρ value decreases with the increasing electron-withdrawing power of the group.