Silyl-nitrogen compounds: Part VII-Reactivity of pentasila-phosphapentazene towards group (IV) halides

Abstract

Pentakis(trimethylsilyl)-3-phospha-2-pentazene, (Me₃Si)₂N-N(SiMe₃)-P=N-N(SiMe₃)₂ (1) reacts with E Cl₄ (E=C, Si) to form phosphine derivative, (Me₃Si)₂N-N(SiMe₃)-P(CI)-N(ECl₂)-N(SiMe₃)₂. This compound undergoes elimination of Me₃ SiCI to form a phosphazene (Me₃Si)₂ N-N=P-N (CCl₃)- N(SiMe₃)₂ in case E=C and a cyclic derivative 3,5,5-trichloro-l,2-bis(trimethylsilyl)-3-bis(trimethylsilyl) amino-l,2,4-triaza-3-phospha-5-silacyclopentane for E=Si. Reaction of (1) with CBr₄ results in an oxidative addition product (Me₂Si)₂N-N(SiMe₃)-P(Br)₂=N-N(SiMe₃)₂ which on heating loses Me₃SiBr to form phosphorane, (Me₃Si)₂N-N=P(Br)=N-N(SiMe₃)₂·