Diphosphonium salts (X3P+-+PX3) 2Y(-) (where X = R or R2N, Y = ClO4 or BF4) were electrochemically synthesized. The reactions between diphosphonium salts and various nucleophiles were studied. The mechanism of quasiphosphonium formation in electrochemical conditions was established by means of competitive electrochemical oxidation of tripropylphosphine in the presence of excess toluene and water. The data obtained were explained based on the supposition about the radical nature of organophosphorus radical-cations in studied reactions.