CRYSTALLINE INCLUSION-COMPOUNDS OF TETRABENZO-18-CROWN-6 WITH UNCHARGED ORGANIC-MOLECULES - SOLID-STATE STRUCTURE OF THE NITROETHANE COMPLEX

Tetrabenzo- 18-crown-6 (1) shows distinct solid-state inclusion proper ties towards a number of OH-acidic, CH-acidic and low-polar uncharged organic molecules. The single crystal X-ray analysis of the inclusion complex between 1 and EtNO2 (1 : 1) is reported. Crystals are monoclin ic, P2(1)/c, with a = 12.887(1), b = 19.365(2), c = 10.776(1) angstrom , beta = 96.33(2)-degrees, D(c) = 1.321 g cm-1, Z = 4. The host macror ing has a conformation similar to a 'dentist's-chair'. The complex is stabilized mainly by C-H...O type interactions involving the methyl gr oup of the EtNO2 guest molecule which is highly disordered. The nitroe thane guests are trapped in channels formed by the host macrocycles.