ELECTROCHEMICAL PROPERTIES OF TETRAETHYNYLETHENES, FULLY CROSS-CONJUGATED PI-CHROMOPHORES, AND TETRAETHYNYLETHENE-BASED CARBON-RICH MOLECULAR RODS AND DEHYDROANNULENES

The redox properties of tetraethynylethenes and carbon-rich molecular rods and dehydroannulenes built from these fully cross-conjugated mole cular construction units are reported here for the first time. All mon omeric and oligomeric cyclic and acyclic tetraethynylethenes are diffi cult to oxidize but undergo stepwise reductions, with the number of di stinct steps increasing with the length of the linearly conjugated all -carbon backbone and the size of the a system. The reductions are also facilitated when the length of the carbon backbone and the number of a electrons in the molecules increase.