CRYSTAL AND MOLECULAR-STRUCTURE OF 9-(TRIETHYLAMINE)-6-THIADECABORANE(11)

The crystal and molecular structure of 9-(triethylamine)-6-thiadecaborane(l 1) was determined by single-crystal X-ray diffraction techniques. The crystals form in the monoclinic space group P21/n with a = 12.142 (2), b = 9.547 (2), and c = 13.553 (2) Å, with β = 107.71 (1)Δ, and with Z = 4. The conventional R index converged at 0.049 with full-matrix least-squares refinement including the overall scale factor, all positional parameters and all anisotropic temperature factors for nonhydrogen atoms, and fixed isotropic temperature factors for hydrogen atoms. The triethylamine ligand is attached to the thiaborane cage in an exopolyhedral manner at the B9 position, with a B-N distance of 1.600 (4) Å, This position of addition probably models the initial mode of interaction of alkenes and alkynes during hydroboration by SB9H11. The sulfur occupies the 6 position and is bound to three borons with an average distance of 1.927 (5) Å. The B-B distances of the cage range from 1.723 (5) to 1.904 (5) Å. The bridging hydrogens on the open face are significantly displaced toward B9 and away from the sulfur. © 1979, American Chemical Society. All rights reserved.