New Electroactive C2 symmetry assemblies based on the biphenyl scaffold and tetrathiafulvalene (TTF) units

Abstract : The synthesis of a family of biphenyl-tetrathiafulvalene derivatives incorporating a binding site has been carried out in good to moderate yields through functionalization of the biphenyl scaffold. X-ray structure of one derivative (compound 3) of the series is provided and shows a dihedral angle of 74° around the central Ar-Ar bond of the biphenyl unit in a cissin conformation. 1H-NMR and cyclic-voltammetry studies demonstrate the critical importance of the nature of the substitution on the conformational rigidity and on the electrochemical behaviour of the resulting biphenyl-TTF assemblies. This feature is underlined by an original electrochemical recognition process upon binding of Pb2+, correlated to conformational changes occurring upon metal cation complexation.