A redox-active tetrathiafulvalene [2]pseudorotaxane: Spectroelectrochemical and cyclic voltammetric studies of the highly-reversible complexation/decomplexation process

The complexation of TTF 2 and cyclobis(paraquat-p-phenylene) 1(4+) has been studied by cyclic voltammetry and by spectroelectrochemistry: shifts in the redox potentials for the TTF and the 1(4+) components of 45 and 30 mV, respectively, occur upon complexation. Decomplexation of 2.1(4+). upon oxidation of the TTF unit to the cation radical species has been monitored by spectroelectrochemistry. The complexation/decomplexation process is highly reversible over at least 10 electrochemical cycles, and this process is accompanied by a color change of the solution from dark green (complexed) to pale brown (uncomplexed) which is clearly visible to the naked eye.