The Role of Alkyl Chains in the Thermoresponse of Supramolecular Network

Abstract Supramolecular materials provide a pathway for achieving precise, highly ordered structures while exhibiting remarkable response to external stimuli, a characteristic not commonly found in covalently bonded materials. The design of self‐assembled materials, where properties could be predicted/design from chemical nature of the individual building blocks, hinges upon our ability to relate macroscopic properties to individual building blocks – a feat which has thus far remained elusive. Here, a design approach is demonstrated to chemically engineer the thermal expansion coefficient of 2D supramolecular networks by over an order of magnitude (\boldmath 120 to \boldmath 1000 × 10 ⁻⁶ K ⁻¹ ). This systematic study provides a clear pathway on how to carefully design the thermal expansion coefficient of a 2D molecular assembly. Specifically, a linear relation has been identified between the length of decorating alkyl chains and the thermal expansion coefficient. Counter‐intuitively, the shorter the chains the larger is the thermal expansion coefficient. This precise control over thermo‐mechanical properties marks a significant leap forward in the de‐novo design of advanced 2D materials. The possibility to chemically engineer their thermo‐mechanical properties holds promise for innovations in sensors, actuators, and responsive materials across diverse fields.