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The Crystal Structure of the 1:1 Complex of Pyromellitic Dianhydride with trans -Stilbene

1974; Oxford University Press; Volume: 47; Issue: 5 Linguagem: Inglês

10.1246/bcsj.47.1081

1348-0634

Toshiko Kodama, Shigekazu Kumakura,

Axial and Atropisomeric Chirality Synthesis

The 1: 1 complex of pyromellitic dianhydride with trans-stilbene crystallizes in the space group P21/c with two pairs of the component molecules in a unit cell with dimensions of a=12.48, b=6.33, c=13.17 A, and β=111.6°. The structure was solved from a three-dimensional |E|2 Patterson synthesis and refined by a block-diagonal least-squares method to a final R value of 0.12 for 1635 reflections. In the trans-stilbene molecule, the plane containing the central ethylene group makes an angle of 11.5° with the phenyl plane. The non-planarity of the trans-stilbene molecule seems to be largely due to a steric repulsion between the hydrogen atom attached to the ethylene moiety and that at the 6 and 6′ position in the phenyl group. The pyromellitic dianhydride molecule is approximately planar. The component molecules are stacked alternately in infinite columns along the a axis. The average spacing between the phenyl plane of trans-stilbene and the molecular plane of pyromellitic dianhydride is 3.59 A, and these pa...