4-Nitro-1-[(trimethyl­sil­yl)ethyn­yl]benzene: low-temperature polymorph at 100 K

The title compound, C₁₁H₁₃NO₂Si, 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 P2₁2₁2₁, the volume decreases by 5% and the mol­ecule distorts. The greatest mol­ecular distortions from C_s symmetry are rotations of the trimethyl­silyl 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).