作者:U. Lawrentz、W. Grahn、I. Dix、P. G. Jones
DOI:10.1107/s0108270198013778
日期:1999.3.15
The two merocyanines 7-(4-dimethylaminophenyl)-2,3, 4,4a,5,6, 10, 10a-octahydroanthracen-2-onc [C22H25NO, (2)] and [2,3,4,4a,5,6,10, 10a-octahydro-7-(5-piperidino-2-thienyl)- 2-anthrylidene]methanedicarbonitrile [C26H27N3S, (4)] show somewhat shortened single bonds [1.434(4)-1.452 (4) Angstrom in (2) and 1.421(4)-1,425(4)Angstrom in (4)] and elongated double bonds [1.345(4)-1.358 (4) Angstrom in (2) and 1.355(4)-1.365(4) Angstrom in (4)] compared to standard bond lengths in polyenes, A comparison of the merocyanines reveals that (4) exhibits a slightly smaller bond length alternation within the rigidized hexatriene moiety than (2), probably because of an increased ground-state polarization.