[2.2.2.2]Paracyclophanetetraenes (PCTs): cyclic structural analogues of poly(p?phenylene vinylene)s (PPVs)

Background: Poly(p-phenylene vinylene)s (PPVs) and [2.2.2.2]paracyclophanetetraene (PCT) are both composed of alternating ?-conjugated para-phenylene vinylene units. However, while the former constitute a class polymers that has been used in organic electronics for decades, latter is macrocycle only recently revealed its potential applications such as battery electrodes. The cyclic structure endows PCT with unusual properties, further tuning these may be required specific applications. Methods: In this article, we adopt an approach often properties PPVs, introduction alkoxy (or alkylthio) substituents at phenylene units, optoelectronic PCT. resulting methoxy- methylthio-substituted PCTs, obtained by Wittig cyclisation reactions, studied UV-vis absorption, photoluminescence, voltammetry measurements, investigated computationally using visualisation chemical shielding tensors (VIST) method. Results: measurements show substitution leads to slight changes terms absorption/emission energies redox potentials having pronounced effect on photoluminescence intensity. computations ring currents associated local global (anti)aromaticity macrocycles, highlighting interplay aromaticity various electronic states. Conclusions: study offers interesting insights into tuneability versatile macrocycles.