Investigations into oxidation induced ring opening of terarylenes containing π-extended thieno[]thiophene units

Four photochromic terarylenes having extended π-conjugated thieno[ b ]thiophene units have been prepared. Photochromic ring-cyclization and cycloreversion behaviour are excluded depending on the position of thieno[ b ]thiophene units. A sponteneous fading reaction involving both thermal and cascade cycloreversion depending on molecular stucture is monitored. Electrochemical and computational studies have been conducted to elucidate the relative stability of their ground and cationic states in both isomers. Four terarylenes having thieno[ b ]thiophene moieties with highly efficient intermolecular cascade ring opening reactivities have been synthesized.