4-Nitro-1-[(trimethyl-sil-yl)ethyn-yl]benzene: low-temperature polymorph at 100 K

Acta Crystallogr Sect E Struct Rep Online. 2012 Sep 1;68(Pt 9):o2652. doi: 10.1107/S1600536812034034. Epub 2012 Aug 8.

Abstract

The title compound, C(11)H(13)NO(2)Si, is a low-temperature form of the previously reported room-temperature structure [Garcia et al. (1998 ▶). Acta Cryst. C54, 489-491]. At 298 K, the material crystallizes in the space group Pnma and occupies a crystallographic mirror plane, but at 100 K the space group changes to P2(1)2(1)2(1), the volume decreases by 5% and the mol-ecule distorts. The greatest mol-ecular distortions from C(s) symmetry are rotations of the trimethyl-silyl and nitro groups by 10.56 (8) and 11.47 (9)°, respectively, to the benzene mean plane. At low temperature, the crystal also becomes an inversion twin, the refined ratio of the twin components being 0.35 (15):0.65 (15).