(2,4,6-Tri-tert-butylphenylimino)thioxo-and -selenoxophosphoranes. Synthesis and structural characterization

A series of stable imino(chalcogeno)phosphoranes R  P( X)  NAr, RPh, 2, 4, 6-Me₃C₆H₂, 2, 4, 6-i-Pr₃C₆H₂; Ar 2, 4, 6-t-Bu₃C₆H₂; X  S, Se ( 5bd, 6b,c ), has been prepared by the oxidation of λ³-imino-phosphines R  P  N  Ar ( 4b-d ) with sulfur and selenium. When P  (tert-butyl)iminophosphine, t-Bu  P  N-  Ar ( 4a ), was reacted with S₈ and Se_iv the corresponding oligomeric metaphosphonimidates 7, 8 were obtained. All new compounds are characterized by their NMR spectra. The constitution of the imino(thioxo)phosphorane 5d is proved by X-ray crystal structure determination.