Several novel oraganophosphorus derivatives have been prepared by the reactions of O, O- diethyl chlorophosphate/thiophosphate with three important series of heterocyclic compounds, viz., bis (mercaptotriazoles), bis (mercaptooxadiazoles), and bis (mercaptothiadiazoles). The derivatives have been characterized on the basis of analyses and spectral (IR, 1H NMR, and 31 P NMR) data. The fungicidal activity of these derivatives ...