Facile dione protection to benzo[1,2-:6,5-']dithiophene-4,5-dione (BDTD) in triggering ultraviolet emission - A new member of the emissive 3,3'-bridged dithiophenes.

To date, 3,3'-bridged dithiophenes with bridges developed from the first period elements (either pristine or oxidised) are non emissive. Benzo[1,2-:6,5-']dithiophene-4,5-dione (BDTD) is a typical 3,3' fused-dithiophene with a dione bridge. It is a critical building block for semiconducting materials, and it is non emissive.