Vinylogous tetrathiafulvalene based podands: complexation interferences on the molecular movements triggered by electron transfer.

Substituted vinylogous tetrathiafulvalenes (TTFVs) containing two freely moving polyoxyethyl chains were prepared. Investigations of their redox behaviors in organic solvent show that these TTFV could efficiently complex metallic dications such as Pb(2+) or Ba(2+), leading to considerable modifications of their electrochemical response. As main feature, the molecule senses the association between the TTFV core and the metallic dication through a modification of the molecular motion triggered by the electron transfer. The complexation creates a link between the two parts of the TTFV core, causing considerable changes in the nature of the molecular motion. The resulting behavior is totally unusual as the 2-positively charged TTFV(2+) appears to present the highest association constants with the metallic dication.