E=SAs>Sb. These reactivities are parallel with the electrochemical oxidation potentials reported for Ph2E and with the first ionization potentials reported for Ph3M. The rate of Φ2Te was faster than that of Ph3P and slightly faster than that of Φ3Sb. From the reactivity of [Φ2E-Me]+ salts with nucleophiles, the E+–Me bond strengths were estimated to increase in the order E=Se
practical approach to phosphoniumsalts has been developed. By the reaction of phosphines and different acid sources with orthoformates in one-step operation, the process allowed rapid access to phosphoniumsalts with diverse counterions in high yield after the purification by recrystallization. The flame retardant performance in PC has also been examined by blending several phosphoniumsalts to PC respectively