SYNTHESIS, X-RAY STRUCTURES, AND REACTIVITY OF THE 1ST BIS(AMINO)METALLASTIBANES AND BIS(AMINO)METALLABISMUTHANES

The reaction of MejSiiN-t-Bu^ECl (E = Sb, Bi) with NaM(CO)„Cp (M = Fe, Mo, W; Cp = j/5-C5H6) affords metallastibanes and bismuthanes, Cp(CO)„ME(N-t-Bu)2SiMe2 (4a-c, 5a-c). The structures of 4c (E = Sb, M = W) and 5c (E = Bi, M = W) have been determined by X-ray crystallography. Both compounds are isotypic and isostructural and crystallize in the triclinic space group with a = 7.030 (9) Â, b= 10.51 (1) Â, c= 16.22 (2) Â, α= 94.1 (1)°, β= 90.4 (1)°, y= 104.9 (1)°, Ζ — 2 for 4c and o= 7.014 (9) Â, b = 10.57 (1) Â, c = 16.25 (2) Â, a = 94.1 (1)°, β — 90.1 (1)°, y — 104.6 (1)°, Ζ = 2 for 5c. The E-W σ-bond lengths are 3.010 (1) Â for Ε = Sb and 3.082 (1) Â for Ε = Bi. The reaction of the antimony derivatives with Fe2(CO)9 yields [Fe(CO)4]Cp(CO)„MSb(N-f-Bu)2SiMe2 (6a-c) as a result of the complexation of the antimony lone pair. The crystal structures of 6a (M = Fe) and 6b (M = Mo) have been determined. 6a crystallizes in the monoclinic space group with a — 10.399 (9) Â, b= 16.76 (2) Â, c= 15.74 (1) Â, β= 94.16 (6)°, and Ζ — 4. Both Sb-Fe bond lengths are almost similar: 2.547 (1) Â for the covalent bond and 2.530 (1) A for the dative bond. 6b crystallizes in the monoclinic space group with α = 12.305 (7) Â, b — 13.812 (7) Â, c = 16.75 (1) Â, β = 99.03 (5)°, and Ζ = 4. The Sb-Mo covalent bond length is 2.871 (1) Â and the Sb-Fe dative bond 2.539 (1) Â. © 1990, American Chemical Society. All rights reserved.