PUB - Publikationen an der Universität Bielefeld

Here we report the syntheses of rare examples of five-coordinated P(V)-phosphates. Oxidation of the phosphazenium phosphoranide [EtP4H][P(C2F5)2F2] (EtP4H = {(Et2N)3P=N}3P=N(H) t Bu) with N2O or S8 affords the corresponding oxophosphate [EtP4H][P(C2F5)2F2O] and thiophosphate [EtP4H][P(C2F5)2F2S]. The oxophosphate was also prepared starting from P(C2F5)3F2 as a precursor. Reaction of P(C2F5)3F2 with water presumably yields the oxonium salt of the hydroxophosphate [P(C2F5)3F2(OH)]-, which undergoes a cation exchange upon treatment with [PPh4]Cl, furnishing [PPh4][P(C2F5)3F2(OH)]. Treatment of the latter with substoichiometric amounts of a strong base initiates HC2F5 elimination yielding [PPh4][P(C2F5)2F2O]. In addition, computational studies were performed to elucidate the description of the oxo- and thiophosphate with Lewis structures.