Phthalocyanine (Pc) and porphyrin (Por) chromophores have been fused through the benzo[α]pyrazine moiety, resulting in unprecedented heteroleptic tetrapyrrole-fused dimers and trimers. The heteroleptic tetrapyrrole nature has been clearly revealed based on single-crystal X-ray diffraction analysis of the zinc dimer. Electrochemical analysis, theoretical calculations, and time-resolved spectroscopic results disclose that the two/three-tetrapyrrole-fused skeletons behave as one totally π-conjugated system as a result of the strong conjugative interaction between/among the tetrapyrrole chromophores. In particular, the effectively extended π-electron system through the fused-bridge induced strong electronic communication between the Pc and Por moieties and large transition dipole moments in the Pc-Por-fused systems, providing high fluorescence quantum yields (>0.13) and relatively long excited state lifetimes (>1.3 ns) in comparison with their homo-tetrapyrrole-fused analogues.
Bibliographical noteFunding Information:
Financial support for the work at University of Science and Technology Beijing was from the National Key Basic Research Program of China (Grant Nos. 2013CB933402, 2012CB224801), National Natural Science Foundation of China (21401009 and 21290174), and Beijing Municipal Commission of Education. The work at Yonsei University has been financially supported by the Global Research Laboratory Program (2013K1A1A2A02050183).
All Science Journal Classification (ASJC) codes
- Organic Chemistry