γ-Herringbone Polymorph of 6,13-Bis(trimethylsilylethynyl)pentacene: A Potential Material for Enhanced Hole Mobility

Abstract

The introduction of the trialkylsilylethynyl group to the acene core is known to predominantly transform the herringbone structure of pentacene to a slip‐stacked packing. However, in this report, we realize the occurrence of an unforeseen polymorph of 6,13‐bis(trimethylsilylethynyl)pentacene (TMS‐pentacene) with an atypical γ‐herringbone packing arrangement. The intermolecular non‐covalent interactions in the γ‐herringbone polymorph are determined from Hirshfeld surface and QTAIM analyses. Furthermore, a comparative SAPT(0) energy decomposition analysis discloses the role of exchange repulsions that govern the molecular packing in the γ‐herringbone polymorph. Moreover, the computationally predicted electronic coupling and anisotropic mobility reveals the possibility of enhanced hole transport (µh=3.7 cm²V‐¹s‐¹) in the γ-herringbone polymorph in contrast to the reported polymorph with the hole mobility of µh=0.1 cm²V-¹s-¹.