TRIPHENYLTELLURIUM(IV) DICHALCOGENOIMIDODIPHOSPHINATES CONTAINING NOVEL 6-MEMBERED TEXYP2N CHELATE RINGS - X-RAY STRUCTURES OF PH3TE[(SPPH2)(OPPH2)N] AND PH3TE[(OPPH2)(2)N]

Several compounds of the type Ph3Te[(XPR2)(YPR'(3))N] (R = Me, Ph; R' = Me, Ph; Y = O, S) were obtained by metathesis reactions between Ph3T eCl and M[(XPR2)(YPR'(2))N]. Two of these, monothioimidodiphosphinato) triphenyltellurium(IV), Ph3Te[(SPPh2)(OPPh2)N] (1) and raphenylimidodi phosphinato)triphenyltellurium(IV), Ph3Te[(OPPh2)(2)N] (2) were obtain ed by metathesis reactions between Ph3TeCl and K[(SPPh2)(OPPh2)M] or K [(OPPh2)(2)N], respectively. The compounds were characterized by IR an d multinuclear (H-1, C-13 and P-31) NMR. The molecular structure of bo th compounds has been determined by X-ray diffractometry. Ph3Te[(SPPh2 )(OPPh2)N] crystallizes in the monoclinic P2(1)/c space group (No. 14) and has the cell parameters a = 13.64(1), b = 13.88(1), c = 20.268(7) Angstrom, beta = 105.37(5)degrees, V = 3699(4) Angstrom(3) and Z = 4, and Ph3Te[(OPPh2)(2)N] crystallizes in the monoclinic C2/c space grou p (No. 15) and has the cell parameters a = 20.748(6), b = 13.824(5), c = 28.093(6) Angstrom, beta = 1 15.48(2)degrees, V = 7274(3) Angstrom( 3) and Z = 8. Both compounds are monomeric and the immediate environme nt about tellurium can be described as octahedral with the apparently stereochemically active lone pair occupying the axial position trans t o a phenyl group from Ph3Te. The other two phenyl groups and two long tellurium-chalcogen secondary interactions [Te ... O 2.77(1) and Te .. . S 3.282(4) in (1) and Te ... O(1) 2.926(6) and Te ... O(2) 2.654(6) Angstrom in (2), respectively] complete the equatorial plane around te llurium. As a result novel situ-membered TeOSP2N and TeO2P2N inorganic chelate rings are formed. Five other compounds, Ph3Te[(SFPh2)(OPMe2)N ], Ph3Te[(SPMe2)(OPPh2)N], Ph3Te[(OPMe2)(OPPh2)N], Ph3Te[(SPMe2)(2)N] and Ph3Te[(SPMe2)(SPPh2)N], were identified unequivocally but unfortun ately attempts to isolate them failed due to decomposition. The reacti on mixtures were investigated by multinuclear (H-1, C-13 and P-31) NMR spectroscopy. (C) 1998 Elsevier Science S.A.