Environmental persistence of organic compounds estimated from structure-reactivity and linear free-energy relationships. Unsaturated aliphatics

Abstract

Structure-reactivity relationships (SRR) and linear free-energy relationships (LFER) are presented for environmentally important chemical reactions of unsaturated aliphatic contaminants in air and water. SRR of the form log k( k=rate constant for reaction with O 3, OH, NO 3 NO 2 and Cl) vs ionization potential, torsional frequency and absorption maximum, as well as LFER of the form log k ( A) vs log k ( B), where A and B = O 3, OH, NO 3, NO 2 or Cl are presented and can be used to estimate reaction rate constants and environmental persistence (in air and water) for many unsaturated compounds for which no data exist. As examples of application, rat constants for reactioons with OH (gas phase), OH (water) and NO 3 (gas phase) are estimated for some 150 unsaturated compounds including alkenes (from monosubstituted to tetrasubstituted), cycloalkenes, dienes, terpenes, aromatic olefins, unsaturated carbonyls, heterocyclic and other unsaturated organics.