Pentaleno[1,2-<i>c</i>:4,5-<i>c</i>′]dithiophene Derivatives: First Synthesis, Properties, and a Molecular Structure

Abstract

Abstract New π-extended pentalene derivatives bearing two thiophene rings are synthesized from 3-bromo-4-ethynylthiopenes as stable orange crystals by using a nickel complex. The observed electronic properties and molecular structure clearly indicate low contribution of the pentalene π system as predicted by the TD-DFT calculations.