CYCLIC S-N COMPOUNDS AND PHOSPHORUS REAGENTS - XVII - SYNTHESIS AND X-RAY STRUCTURAL CHARACTERIZATION OF (PH)(DCA)(ME2N)P=N-S3N3 HETEROCYCLE

The phosphiniminocyclotrithiazene, (Ph)(DCA) (Me2N)PN-S3N3 (II) [DCA = dicyclohexylamino] was obtained in approximate to 70% yield from room temperature reaction of S4N4 with the corresponding phosphine, (Ph)(D CA)(Me2N)P (I). Single crystal X-ray structure determination of (II) r eveals slightly different P-N bond lengths around phosphorus [P-N(4): 1.607; P-N(5): 1.645 and P-N(6): 1.638 Angstrom] and almost planar con figuration around both N(5) and N(6). The tricoordinate sulphur [S(1)] substantially deviates (0.663 Angstrom) from the mean plane of the he terocycle. The structural parameters of(II) are compared with the rece ntly reported diethylamino and di-n-butylamino analogues. (II) affords (Ph)(DCA)(Me2N)P = N-S3N (IV) in approximate to 60% yield on thermoly sis in solution.