Robert V. Berthold

Fluorescence spectra of some simple coumarins.

Abstract The fluorescence spectra of six representative coumarins containing hydroxyl and/or alkoxyl substituents have been determined and compared on several commercial instruments. Measurements in methanol, dilute sulfuric acid, and dilute alkaline buffer permitted characterization of coumarin type, and observation of the change of fluorescent intensity with time allowed further refinement. Application of the method to paper chromatogram eluates, combined with an inherently high degree of sensitivity, should make it especially useful in the investigation of natural products.

3,4-Dichlorobenzyl Methylcarbamate and Related Compounds as Herbicides

3,4-Dichlorobenzyl methylcarbainate is a selective preemergence herbicide active against both grass and broadleaf weeds. Synthesis of pigment is inhibited in species sensitive to this chemical. Minor structural modifications, such as positioning of the chlorine on the phenyl ring or variations in the N-substituent, significantly alter its activity.