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

## TL;DR

Scientists used a new method to change how organic semiconductor molecules pack together, preserving their properties while allowing for design flexibility.

## Contribution

A supramolecular synthon substitution approach is introduced to replace C–I···π interactions with C–I···N interactions in organic semiconductor cocrystals.

## Key findings

- Cocrystals of DPA and DPyA with halogenated coformers were successfully synthesized.
- Replacing [C–I···π] with [C–I···N] interactions preserved OSC photophysical properties and conformations.
- The method offers a reliable way to modulate properties of organic semiconductors and their isosteres.

## Abstract

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 (DPA) and its isostere 9,10-dipyridylanthracene
(DPyA) with halogenated coformers 1,2-diiodotetrafluorobenzene
(1,2-C
6
I
2
F
4), 1,4-diiodotetrafluorobenzene (1,4-C
6
I
2
F
4), and
1,3,5-triiodotrifluorobenzene (1,3,5-C
6
I
3
F
3). The strategy enables
reliable replacement of [C–I···π] interactions
in DPA cocrystals with [C–I···N]
interactions in the corresponding DPyA 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.