Altering the Emission Behavior with the Turn of a Thiophene Ring: The Photophysics of Condensed Ring Systems of Alternating Benzenes and Thiophenes

Six aromatic compounds with embedded thiophenes differing in the number of rings (2−5) and thiophene orientation along the long axis of the molecule (syn, anti) were investigated. Photophysical properties, steady-state absorption, fluorescence, phosphorescence, lifetimes, quantum yields, and a comprehensive time-resolved spectroscopic analysis (femtosecond and nanosecond transient absorption spectroscopy) have been studied as a function of molecular structure.