ISSN:
1042-7163
Keywords:
Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A racemic solution of 2,2′-biphenyldisulfide (I), C12H8S2, produces conglomerate crystals of (I) belonging in space group P3221 (no. 154) with lattice constants: a = 7.38 (3) Å, b = 7.38 (3), c = 16.20 (2) Å; V = 766.6 Å3 and d(calc; M.W. = 216.32, z = 3) = 1.406 g-cm-3, d(meas) = 1.47 g-cm-3. A total of 1150 data were collected over the range of 4° ≤ 2θ ≤ 60° using film data (Weissenberg); of these, 448 [independent and with I ≥ 3σ(I)] were used in the structural analysis. Refinement converged to final residuals of 0.080 and 0.082 for R(F) and RW(F), respectively. The molecule is located at the twofold axis of the space group.A solution of 2,2′-biphenyldisulfide mono-oxide (II), C12H8S2O, produces centrosymmetric crystals of II belonging in space group P21/c with lattice constants: a = 9.947 (1) Å, b = 7.162 (2), c = 15.420 (3) Å, and β = 107.56 (1)°; V = 107.56 (1) Å3 and d(calc; M.W. = 232.31, Z = 4) = 1.473 g-cm-3. A total of 2114 data were collected over the range of 4° ≤ 2θ ≤ 50°; of these, 1089 [independent and with I ≥ 2.5σ(I)] were used in the structural analysis. Data were corrected for absorption (μ = 4.539 cm-1), and the relative transmission coefficients ranged from 0.9198 to 0.9998. Refinement converged to final residuals of 0.0313 and 0.0300 for R(F) and Rw(F), respectively.For I, the central six-membered ring C4S2 contains a helical C2S2 fragment whose conformational chirality is defined by a torsional angle of 59.98°. The benzene rings are the expected, planar hexagons characteristic of aryl rings. By comparison with I, the torsional angle of the C2S2 fragment of the mono-oxide is diminished (52.9°) by the introduction of the S=O fragment. We believe alteration of molecules (such as functionalization) causing large changes in torsional angles of helical fragments of molecules may play a role in the selection of their crystallization mode; however, it is not the only factor dictating that choice, which is also affected by steric hindrance to the formation of short intermolecular contacts leading, in the solid state, to the formation of homochiral, infinite helical strings, as we shall demonstrate in the text. This study clearly shows the influence of those contacts on the formation of the strings. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:65-74, 1998
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
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