Cyclophane, XVI. Die Kristallstruktur von 4,5,7,8,12,13,15,16‐Octamethyl[2.2]‐paracyclophan

Cyclophanes, XVI. The Crystal Structure of 4,5,7,8,12,13,15,16‐Octamethyl[2.2]paracyclophane The title compound 1a crystallizes in space group I 2/ c with Z = 8 molecules per cell. The structure consists of two independent centrosymmetric molecules, which differ only slightly in respect to thermal vibrations (pseudo‐symmetry: 2/ m ). The two six‐membered rings are shifted by 0.62 Å resulting in a torsion angle of 15° for the dimethylene‐bridges (CC = 1.56 Å). The tetramethylbenzene rings are folded to a V‐shape angle of 17.5°. The distance of the rings amounts to 3.16 Å. The final R ‐value for 1811 observed reflexions was 0.085.