ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Accurate low-temperature X-ray crystal structures of the isomeric Diels-Alder monoadducts of C70 1a, bridged at the [6,6] bond between C(1) and C(9), and 1b, bridged at the [6,6] bond between C(7) and C(8), have been determined. The latter structure is the first one solved for a 7,8-C70 monoadduct. The C1-symmetrical 1a and Cs-symmetrical 1b co-crystallize with CS2 molecules in the space groups P21/c and Pnma, respectively, and the distances between bridgehead atoms are 1.603(3) and 1.584(3) Å. The degree of pyramidalization of atoms involved in [6,6] bonds near the ‘unsubstituted’ pole and near the equator of the fullerene was estimated; it is shown for the unsubstituted pole region that atoms corresponding to C(1) and C(9) are slightly more pyramidal than those corresponding to C(7) and C(8), in agreement with ab initio calculations obtained for the C70 spheroid. Some aspects of the crystal packings are discussed.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19950780207