Haumann, T.; Benet-Buchholz, J.; Boese, R.:
Structural effects of spiroconjugation: crystal structures of spiro[4.4]nonatetraene and spiro[4.4]nona-1,3,7-triene.
1996
In: Journal of Molecular Structure (J.Mol.Struct.), Band 374 (1996), S. 299 - 304
Artikel/Aufsatz in Zeitschrift / Fach: Chemie
Titel:
Structural effects of spiroconjugation: crystal structures of spiro[4.4]nonatetraene and spiro[4.4]nona-1,3,7-triene.
Autor(in):
Haumann, T.; Benet-Buchholz, J.; Boese, R. im Online-Personal- und -Vorlesungsverzeichnis LSF anzeigen
Erscheinungsjahr
1996
Erschienen in:
Journal of Molecular Structure (J.Mol.Struct.), Band 374 (1996), S. 299 - 304
ISSN

Abstract:

Spiro-polyenes, compds. with two perpendicular p-systems joined by a common spiro-atom, exhibit through-space spiroconjugation. One important representative of spiroconjugated systems is spiro[4.4]nonatetraene (3). The mol. structures of spiro[4.4]nona-1,3,7-triene (2) and (3) were detd. by x-ray diffraction and compared with the redetd. structure of cyclopentadiene (1) to detect the slight distortions expected from spiroconjugation. Crystallog. data are given. Comparison of bond lengths and angles reveals a slight shortening of the double bonds and a small elongation of the single bonds connecting the spiro atom in (3). The same effect is also found from ab initio calcns. at Hartree-Fock level 6-31G*, although to a minor extent. This is shown by applying a difference anal. of structural parameters to cancel out the systematic errors and differences of both methods.