SYNTHESIS AND CHARACTERIZATION OF FIRST-ROW TRANSITION-METAL TELLUROLATES - X-RAY CRYSTAL-STRUCTURES OF MN[TESI(SIME(3))(3)](2)(DMPE), FE[TESI(SIME(3))(3)](2)(DMPE)(2), FE[TESI(SIME(3))(3)](CL)(DMPE)(2), AND CO[TESI(SIME(3))(3)](PME(3))(3)

The syntheses of several first-row transition metal tellurolate derivatives incorporating the sterically encumbered ligand -TeSi(SiMe(3))(3) are described. Metathesis reactions of MCl(2)(dmpe)(2) (M = Cr, Mn, Fe) or CoBr2(PMe(3))(3) with [(THF)(2)LiTeSi(SiMe(3))(3)](2) yield M [TeSi(SiMe(3))(3)](2)(dmpe)(2) and Co[TeSi(SiMe(3))(3)](PMe(3))(3), respectively. Tellurolysis of the transition metal amides M[N(SiMe(3))(2)](2) with HTeSi(SiMe(3))(3) in the presence of Lewis bases yields M[TeSi(SiMe(3))(3)](2)L(2) (M = Mn, L = 4-tert-butylpyridine or 1/2 dmpe (dmpe 1,2-bis(dimethylphosphino)ethane);M = Fe, L = dmpe). The compounds have been characterized by a combination of NMR spectroscopy, magnetic measurements, and elemental analyses. In addition, four derivatives have been structurally characterized by X-ray crystallography. Mn[TeSi(SiMe(3))(3)](2)(dmpe)(2) crystallizes in the space group P2(1)2(1)2(1) with a=13.104(3) Angstrom, b=25.523(6)Angstrom, c=28.504(4)Angstrom, V=9533(5)Angstrom(3), d(calc)=1.33 g cm(-1), Z = 8, R = 3.90%, and R(W) = 3.96%. Crystal data for Fe[TeSi(SiMe(3))(3)](2)(dmpe)(2): space group <P(1)over bar> with a=9.556(2)Angstrom,b=9.814(2)Angstrom, c=32.990(5) A, V=2672.4(8)Angstrom(3), d(calc)=1.37 g cm(-1), Z = 2, R = 6.13%, and R(W)=7.09%. Fe[TeSi(SiMe(3))(3)](Cl)(dmpe)(2) crystallizes in the space group P2(1)/c with a=9.317(2)Angstrom, b=11.898(2)Angstrom, c=32.836(7)Angstrom, V=3637(1)Angstrom(3), d(calc)=1.40 g cm(-1), Z = 4, R=3.31%, and R(W)=3.52%. The crystal structure of Co[TeSi(SiMe(3))(3)](PMe(3))(3) was also determined; it crystallizes in the space group P2(1)/c with a=17.651(5)Angstrom, b=12.435(3)Angstrom, c=17.704(4)Angstrom, V=3418(1) A(3), d(calc)=1.29 g cm(-1), Z = 4, R=5.92%, and R(W)=7.67%