Synthesis and photophysical properties of 3,5-diaryl-2-heteroarylthiophenes

A series of 3,5-diaryl-2-heteroarylthiophenes have been synthesized via Fiesselmann type reaction between alkynones and easily available heteroarylmethanethiols or heteroarylmethyl carbamimidothioates. A correlation between compounds structure and efficiency of luminescence has been established. These compounds exhibited photoluminescence with quantum yields up to 83%. An evidence of twisted intramolecular charge transfer and singlet emissive states have been demonstrated.