[2n]Para[44–n]paracyclophanes; synthesis, structure, and cyclic voltammetry

Abstract

Three new unsaturated [2_n]para[4_4–n]paracyclophanes (n= 1, 2, or 3) have been prepared by a new multiple Witting reaction. The structures and electron delocalisation of the neutral compounds and the anions are discussed. The latter were obtained by cyclic voltammetry at a mercury drop. Unsaturated cyclophanes with electron conjugation along the perimeter form stable dianions if the number of π-electrons is 4n+ 2 in the dianions.