A QUANTUM-CHEMICAL STUDY OF LIGHT-DEPENDENT HERBICIDES

Common structural features were investigated for ''light-dependent her bicides'' (LDHs, also called peroxidizing or photobleaching herbicides ). Quantum chemical calculations of 143 herbicidal compounds revealed that LUMO levels of LDHs were similar and strikingly low. Using the LU MO position as an anchor, presumably known structure-activity relation ships could be explained. Overall molecular similarity between oxyfluo rfen and chlorophthalim was examined by molecular field fitting. The r esult supported LUMO position correspondence.