The phosphorus–oxygen bond formation reactions often observed for the sterically crowded triarylphosphines and their radical cations were studied by DFT calculation. oxidations of trimethyl-, triphenyl-, trimesityl-phosphines to corresponding phosphine oxides with peroxides are shown proceed through SN2 like transition states overall influence steric hindrance on activation energy is limited. r...

an investigation was made to study the residual activity and air- borne effect of pirimiphos- methyl, at 2g a.i./m2 in hut scale trials on different surfaces in kazeroun, and bandar-abbas, south of iran. in kazeroun area, bio-assay contact mortality test with pirimiphos methyl on mud, wood, cement and plaster surfaces, 54 days after hut spraying, decreased from 100% to 46.7%, 61.25%, 36.6% and ...