Molecular complexes. Part XIV. Crystal and molecular structure of the π*-electron-acceptor molecule 1,2,4,5-tetracyanobenzene

Crystals of the title compound are monoclinic, unit-cell dimensions a= 6·51, b= 13·79, c= 10·44, γ= 112·0, spacegroup P21/b, Z= 4. The crystal and molecular structure has been determined from visually estimated three-dimensional photographic data by direct methods and refined by full-matrix least squares to R 0·091 for 880 independent reflections. After correction for rigid-body motion the mean CN, C–CN, and C–C(benzene ring) bond lengths are 1·140, 1·446, and 1·401 Å. The internal angles in the benzene ring are significantly different from 120°.