Highly Conducting and Flexible Radical Crystals

Abstract

Together with high conductivity, high flexibility is an important property required for next generation organic electronic components. Both properties are difficult to achieve together especially when the components are crystalline because of the intrinsic high brittleness of organic molecular crystals. We report an organic radical crystal system that has both high flexibility and high conductivity. The crystal consists of 9,10‐bis(phenylethynyl)anthracene radical cation (BPEA.+) units, and shows flexibility under pressure with high conductivity in ambient condition exhibiting average conductivity of 2.68 S cm−1 when normal linear shape, as well as 2.43 S cm−1 when bent. The structural analysis reveals that both a short π–π distance (3.290 Å) between BPEA.+ units that are aligned along the crystal length direction, and the presence of PF6− counter ions induce flexibility and high electrical conductivity.

Stepwise Tuning the Mechanical Flexibility of 1D Coordination Polymer Single Crystals

“…It is now clear that materials exist which exhibit simultaneously bulk mechanical flexibility and single crystal-like functional properties. 1 Such dualfunction materials are being explored for various applications including in nano-optical, 2 nano-electronic, 3 and mechanicallyactuating technologies. 4,5 Defined by the reversibility of their response to mechanical loading, both elastic (reversible) and plastic (irreversible) crystals have been identified.…”