SYNTHESIS, STRUCTURAL CHARACTERIZATION, AND REACTIVITY OF THE BIS(ETA-5-DICARBOLLIDE)SILICON SANDWICH COMPOUND COMMO-3,3'-SI(3,1,2-SIC2B9H11)2

The bis(dicarbollide)silicon sandwich compound commo-3,3ʹ-Si(3,l,2-SiC2B9H11)2 (1) has been prepared and structurally characterized by a single-crystal X-ray diffraction study. Complete details of this study as well as the results of reactivity studies of 1 are reported. Compound 1 reacts with Lewis bases. Structures of products resulting from the reaction of 1 with pyridine, (10-exo-η1-7,8-C2B9H11)(10-endo-η1-7,8-C2B9H11)Si(C5H5N)2 (4), and trimethylphosphine, [η5-10-{(Me3P)2BH}C2B8H10]Si(η1-C2B9H11) (5), have been determined by X-ray diffraction studies. Species 1 crystallizes in the space group P21/n with a = 6.9956 (6) Å, b = 9.6804 (10) Å, c = 12.2838 (22) Å,β = 91.800 (11)0, V = 831 Å3, and Z = 2. Data were collected to a maximum of 2θ = 54°, giving 1818 unique reflections. The final discrepancy indices were R = 0.050 and Rw = 0.068 for 1282 independent reflections. Compound 4 crystallizes in the space group P21/c with a = 10.645 (1) Å, b = 12.437 (2) Å, c = 19.256 (2) Å, β = 94.333 (4)°, V = 2537 Å3, and Z = 4. Data were collected to a maximum of 2θ = 50°, giving 4482 unique reflections. The final discrepancy indices were R = 0.052 and RW = 0.068 for 3065 independent reflections. Derivative 5 crystallizes in the space group P21/n with a = 8.640 (1) Å, b = 12.690 (2) Å, c = 23.626 (3) Å, β = 92.549 (5)°, V = 2588 Å3, and Z = 4. Data were collected to a maximum of 2θ = 50°, giving 4560 unique reflections. The final discrepancy indices were R = 0.048 and Rw = 0.057 for 2925 independent reflections. © 1990, American Chemical Society. All rights reserved.