Ambidentate nucleophiles. Part 3. Reactions of phosphoroselenoates with molecular halides: the use of 1J(PSe) as a structural diagnostic

Abstract

Sodium OO′-di-isopropyl phosphoroselenoate, Na[SeOP(OPrⁱ)₂](Na[L]), reacts with molecular halides of carbon, silicon, germanium, tin, phosphorus, arsenic, and sulphur to give derivatives ML_n. Comparison of the values of ¹J(PSe) in the products with those in a number ofmodel compounds indicates that O-bonded isomers M[OP(OPrⁱ)₂Se] are formed in LCOPh and PL₃, that Se-bonded isomers M[SePO(OPrⁱ)₂] are formed in LC₂H₅, SiMe₃L, GePh₃L, SnPh₃L, AsL₃, LSO₂Ph, and L₂, while SnMe₃L, SnPh₂L₂, and SnPhL₃ probably contain bidentate L. The esters P(OR)₃Se (RMe or Et) are inert to reactionwith molecular halides. The compound P(OEt)₃Se is a much weaker base than PPh₃Se which itself is much weaker than PPh₃O.