Year of publication
- 2009 (3) (remove)
- 9,9-Dimethyl-9-silafluorene (2009)
- The title compound, C14H14Si, crystallizes with two almost identical molecules (r.m.s. deviation = 0.080 Å for all non-H atoms) in the asymmetric unit. All atoms of the silafluorene moiety lie in a common plane (r.m.s. deviations = 0.049 and 0.035 Å for the two molecules in the asymmetric unit). The Si-Cmethyl bonds are significantly shorter [1.865 (4)-1.868 (4) Å] than the Si-Caromatic bonds [1.882 (3)-1.892 (3) Å]. Owing to strain in the five-membered ring, the endocyclic C-Si-C angles are reduced to 91.05 (14) and 91.21 (14)°. Key indicators: single-crystal X-ray study; T = 173 K; mean σ(C–C) = 0.005 A°; R factor = 0.061; wR factor = 0.157; data-to-parameter ratio = 16.3.
- (18-Crown-6-[kappa]6O)(pyrazolato-[kappa]2N,N')-potassium(I) (2009)
- The asymmetric unit of the title compound, [K(C3H3N2)(C12H24O6)], is composed of a potassium cation bonded to the six O atoms of a crown ether molecule and the two N atoms of a pyrazolate anion. The K...O distances range from 2.8416 (8) to 3.0025 (8) Å, and the two K...N distances are 2.7441 (11) and 2.7654 (11) Å. The K cation is displaced by 0.8437 (4) Å from the best plane through the six O atoms. The latter plane is almost perpendicular to the plane of the pyrazolate ring [dihedral angle 83.93 (3)°]. Key indicators: single-crystal X-ray study; T = 173 K; mean σ(C–C) = 0.002 A°; R factor = 0.026; wR factor = 0.066; data-to-parameter ratio = 16.5.
- Dibromidotris(dimethylamine)-magnesium(II) (2009)
- The Mg centre in the title compound, [MgBr2(C2H7N)3], is pentacoordinated in a trigonal-bipyramidal mode with the two Br atoms in axial positions and the N atoms of the dimethylamine ligands in equatorial positions. The MgII centre is located on a crystallographic twofold rotation axis. The crystal structure is stabilized by N-H...Br hydrogen bonds. The N atom and H atoms of one dimethylamine ligand are disordered over two equally occupied positions. Key indicators: single-crystal X-ray study; T = 173 K; mean σ(N–C) = 0.005 A° ; disorder in main residue; R factor = 0.022; wR factor = 0.049; data-to-parameter ratio = 21.1.