Structure of sulfonosine

Rhodium Complexes Based on Phosphorus Diamide Ligands: Catalyst Structure versus Activity and Selectivity in the Hydroformylation of Alkenes

“…A weighting scheme of w ) [2.5 + 0.01(σ-(Fo)) 2 + 0.01/(σ(Fo))] -1 was used for 3d. The secondary isotropic extinction coefficient 46,47 was refined to Ext ) 0.059(5) (1c), Crystal Structure Determination of 4. Crystal data: C43H61N9O7P3‚3C6H6, fw ) 1246.15, yellow block, 0.55 × 0.30 × 0.10 mm 3 , trigonal, R3c (No.…”

Solid-State Stereochemistry of (−)-Scopolamine Hydrobromide Sesquihydrate, a New Polymorph of the Anticholinergic Drug

“…The structure [ (C,-S)-absolute configuration for the (-)-enanti~mer'~] was solved by the application of direct methods and refined by least squares with the NRCVAX program. 16 Because the minimum and maximum transmission factors were, respectively, 0.239 and 0.500, an empirical absorption correction was applied. An isotropic extinction coefficient value of 0.19 (5) was included in the refinement16 to account for secondary extinction effects.17 Atomic scattering factors stored in the NRCVAX program were those of Cromer and Waber.I8 Hydrogen atoms were placed at calculated positions except for those attached to atoms 0(4), 0(5), 0(6), and N [positions were those from the difference Fourier map].…”

Unique and Effective Characterization of Space Groups in Computer Applications

“…Moreover, huge amount of data and a possibility of human errors in transferring the symmetry information to applications involving crystal symmetry [2,3] leads to the generally accepted conclusion, that the automated derivation of space-group information becomes essential when this information is routinely required, especially in the case of higher symmetry. In the years 1960-1980 welldocumented algorithms [4,5] translating H-M symbols into a set of generators, which are then used to build a full set of symmetry matrices, were developed. Differences in the generated space group descriptions, caused by ambiguities in H-M symbols prompted in [6][7][8], brought to procedures based on explicit-origin generators, that is on symmetry operations with specified complete translation vectors not only on its characteristic components -glide or screw vectors.…”