Single crystal structure of [(Me 2 N-C 6 H 4 ) 2 C + – + C(C 6 H 4 -NMe 2 ) 2 ](I 3 – ) 2 : a twisted tetraphenylethylene dication with a C–C single bond

The cyanine distortion of doubly charged ethylenes leading to twisted molecular halves connected by a C–C single bond inciudes tetrakis(p-dimethylaminophenyl)ethylene, which on twofold oxidation with iodine increases its twist angle ω from 19 to 53° and its central CC bond length from 135 to 150 pm as predicted by PM3 calculations.