Manipulating Crystal Packing in Heterocycloarenes by an Atom Engineering Strategy for High-Mobility Organic...

Developing (hetero)cycloarenes, an emerging class of ring-shaped organic semiconductors (OSCs), for high-performance optoelectronic applications remains significantly constrained due to their synthetic challenge and limited diversity of available materials. Herein, a series of coplanar chalcogen-fused heterocycloarenes NO, NS, and NSe with long branched alkyl chains were synthesized in single-crystal form, and chalcogen atom engineering on heterocycloarenes was investigated in detailed. Sulfur-fused NS exhibits a closest herringbone crystal packing with π-π stacking distance as low as 3.11 Å, resulting in a record-high hole mobility of 3.13 cm² V^-1 s^-1 among all reported ring-shaped OSCs. Remarkably, selenium-fused NSe without intermolecular π-π interactions in its crystalline state, also manifests the second highest mobility of up to 2.11 cm² V^-1 s^-1, which is attributed to the presence of extensive short-range edge-to-face Se…π and C-H…π interactions. Furthermore, these heterocycloarenes exhibit a selective supramolecular interaction with C₇₀, with the trend in binding constants being: NS < NO < NSe. Overall, this work not only systematically elucidates the role of atom engineering on heterocycloarenes for the first time, but also paves the way for practical applications of the emerging ring-shaped OSC materials.