INFRARED SPECTROSCOPY-BASED PROPERTY REACTIVITY CORRELATIONS FOR PREDICTING ENVIRONMENTAL FATE OF ORGANIC-CHEMICALS

A conventional structure-activity relationship (SAR) has been established between the alkaline hydrolysis rate constants (k(OH)) of 12 alkyl and aryl formates and acetates and the linear combination of the frequencies of the C=O and C-O infrared (IR) absorbance peaks. The inability of this relationship to predict k(OH) values for more structurally diverse carboxylic acid esters led to the development of a prototype of a prediction system that employs multiple linear regression analysis, using points from the Fourier transforms (FTs) of IR spectra. Conventional SARs have also been observed between single IR peak parameters and the microbial degradation rate constants of amides (C=O peak frequencies), 2,4-dichlorophenoxyacetate esters (C-H peak intensities), phenols (O-H peak frequencies), and anilines (N-H stretching peak intensities). These observations indicate the feasibility of extending the FT-based prediction system to microbial degradation when reliable rates are available for additional compounds.