Synthesis and Photophysical Properties of Cyclic Homodimer of U‑Shaped Dibenzophenazinylene

A new class of cyclic π-extended heteroarylene
oligomercyclic
homodimer of U-shaped dibenzophenazinylenehas been successfully
synthesized and characterized. NMR spectroscopy and DFT calculations
implicated the unique topologies of the macrocycle. The cyclic dimer
displays intense green-to-yellow fluorescence in both solution and
the solid state. Remarkably, it shows acid-responsive color changes
and a photoluminescence “turn-OFF” response upon protonation.
The heteroaromatic macrocycle represents a versatile scaffold for
the development of advanced optoelectronic materials and supramolecular
host–guest systems.