PHOSPHORANE IMINATO-TRICHLOROSELENATES(II ) - SYNTHESES AND CRYSTAL-STRUCTURES OF [SECL(NPPH3)2]- AND [ME3SIN(H)PME3]2+[SE2CL6]2-(SECL3)

[SeCl(NPPh3)2]+SeCl3- has been synthesized by the reaction of Se2Cl2 w ith Me3SiNPPh3 in acetonitrile solution, forming orangered crystals, w hereas red crystals of [Me3SiN(H)PMe3]2+[Se2Cl6]2- were obtained by th e reaction of Me3SiNPMe3 with SeOCl2, in acetonitrile solution. Both c omplexes were characterized by X-ray structure determinations. [SeCl(N PPh3)2]+SeCl3-: Space group P2(1)/n, Z = 4, structure solution with 74 89 observed unique reflections, R = 0.057. Lattice dimensions at -60-d egrees-C: a = 1117.0, b = 2241, c = 1407.5 pm, beta = 95.61-degrees. I n the cation [SeCl(NPPh3)2]+ the selenium atom is phi-tetrahedrally co ordinated by the chlorine atom and by the nitrogen atoms of the phosph orane iminato ligands, whereas the anion SeCl3- has a T-shaped structu re with phi-trigonal-bipyramidale surrounding of the selenium atom. [M e3SiN(H)PMe3]2+[Se2Cl6]2-: Space group P2(1)/c, Z = 4, structure solut ion with 2093 observed unique reflections, R = 0.080. Lattice dimensio ns at -70-degrees-C: a = 956, b = 828, c = 1973 pm, beta = 93.800. The structure consists of [Me3SiN(H)PMe3]+ ions and planar [Se2Cl6]2- ani ons, in which the selenium atoms are bridged nearly symmetrically by t wo chlorine atoms.