Negative Thermal Expansion in Discotic Liquid Crystals of Nanographenes

Abstract

Hexa-peri-hexabenzocoronene derivatives show a record high negative volumetric thermal expansion coefficient within the crystalline phase. Responsible for the negative thermal expansion is the increase of the tilt angle and the improved packing of the discotic cores with temperature and this has implications in the design of organic electronic devices as well as in advanced nanocomposites with controlled thermal properties.