The crystal and molecular structure of 2,3,12,13-tetrathia[4,4]metacyclophane

Conformations in a variety of cyclophane structures are discussed, as determined by X-ray diffraction in crystals and by 1 Hmr in solution. Established nomenclature is brought forward (syn/anti and synclinal/anticlinal) and used to deal with an intermediate case which has been examined by both techniques. The crystal and molecular structure of the title compound, C 16 H 16 S 4 , is determined and refined to R = 0.0497. The crystal is orthorhombic, space group Pbca, a = 16.593(2), b = 10.018(2), c = 19.407(3) Å at 25(2) °C, Z = 8, D calc = 1.386 g cm −3 . The molecular conformation in the crystal is anticlinal with a dihedral angle between the benzene rings of 101°. The benzene rings are displaced laterally by 0.727 Å and the sequence of torsion angles is similar in the two bridging chains.