Synthesis and properties of the octaethylporphyrin–dihexylbithiophene–pyridine system (OEP–DHBTh–Py) connected with diacetylene linkage. Proton-mediated and heat-driven spectral changes

Orientational isomers of the octaethylporphyrin–dihexylbithiophene–pyridine system (OEP–DHBTh–Py) connected with the diacetylene linkage were synthesized. The spectral measurements were performed under neutral and acidic conditions, clearly proving that the orientation of DHBTh affects not only the electronic structures of OEP–DHBTh–Py but also their proton-mediated spectral changes.