5,5-Dimethyl-2,8-diphenyl-5H-dibenzo[b,f]silepine: a synchrotron study
International Union of Crystallography, 2013
Acta Crystallographica Section C
Volume 69, Issue 4, pages 436–438, April 2013
How to Cite
Clegg, W., Harrington, R. W., Mercier, L. G. and Piers, W. E. (2013), 5,5-Dimethyl-2,8-diphenyl-5H-dibenzo[b,f]silepine: a synchrotron study. Acta Crystallographica Section C, 69: 436–438. doi: 10.1107/S0108270113005659
The molecule of the title silepine compound, C28H24Si, lies on a crystallographic general position but has almost exact mirror symmetry. The seven-membered silepine ring has a boat conformation, with a fold angle of 99.99 (9)° between the C—C=C—C stern and the C—Si—C prow. The planes of the phenyl substituents are rotated by 32.23 (6) and 31.80 (7)° out of the planes of the respective fused benzene rings. Similar folded conformations are found for other dibenzo[b,f]silepines, while analogous dibenzo[b,f]borepines, in which the B atom can participate in conjugation, have a more flattened heterocyclic ring.