Synthon Substitution via C–I···π and C–I···N Halogen Bonds in Cocrystals of Anthracene-Based Organic Semiconductor Isosteres

Cocrystallization is a versatile supramolecular synthetic strategy for tuning the properties of organic semiconductors (OSCs) and related polycyclic aromatic hydrocarbons (PAHs) by controlling their packing and architectures with suitable coformers. In this study, we demonstrate a supramolecular synthon substitution approach to afford cocrystals of 9,10-diphenylanthracene (<b>DPA</b>) and its isostere 9,10-dipyridylanthracene (<b>DPyA</b>) with halogenated coformers 1,2-diiodotetrafluorobenzene (<b>1,2-C</b> ₆ <b>I</b> ₂ <b>F</b> ₄), 1,4-diiodotetrafluorobenzene (<b>1,4-C</b> ₆ <b>I</b> ₂ <b>F</b> ₄), and 1,3,5-triiodotrifluorobenzene (<b>1,3,5-C</b> ₆ <b>I</b> ₃ <b>F</b> ₃). The strategy enables reliable replacement of [C-I···π] interactions in <b>DPA</b> cocrystals with [C-I···N] interactions in the corresponding <b>DPyA</b> cocrystals. Although coformers and substitutions alter the supramolecular architectures, the photophysical properties and molecular conformations of the OSC building blocks remain largely preserved. The results highlight synthon substitution as a reliable supramolecular design element that accelerates the derivatization of established OSCs and their isosteres, offering opportunities for property modulation.