Abstract
The structure of the cross-conjugated compound 2,3-diphenylbutadiene
was investigated by single-crystal X-ray
diffraction and computational methods. In the crystal structure
the central butadiene fragment adopts an s-gauche geometry
[-55.6(2)° torsion angle φ around the essential single
bond], whereas the styrene moieties are close to planarity.
MP2/6-311G* calculations show that the s-gauche conformation
represents the global minimum along the φ coordinate,
but also revealed the existence of an s-trans local minimum.
While the crystal structure seems to reflect dominance of styrene-
like conjugation, the MP2/6-311G* calculations indicate
that conjugation in both the styrene and butadiene π-
systems is important. An NBO orbital deletion study shows
that the structure is primarily determined by (hyper)conjugation
and that steric effects play a minor role.
Original language | Undefined/Unknown |
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Pages (from-to) | 4746-4751 |
Number of pages | 6 |
Journal | European Journal of Organic Chemistry |
Volume | 2007 |
Issue number | 28 |
Publication status | Published - 2007 |