Converting ambient thermal fluctuations into selective chemical transformations represents an emerging strategy in sustainable catalysis. Unlike conventional thermocatalysis that requires continuous high-temperature input, we report a molecular ferroelectric platform that harnesses low-grade temperature fluctuations, spanning industrial, environmental, biological, and mechanical sources, to drive efficient and tunable catalytic reactions. Two copper-based molecular ferroelectrics, [Cu(L-His)(bpy)]ClO₄ (Cu-FE-1) and [Cu(L-phe)(bpy)(H₂O)]PF₆·H₂O (Cu-FE-2), were rationally designed to elucidate the impact of coordination environment and the dipolar orientation on catalytic performance. For example, under simulated industrial waste heat cycling, both compounds exhibited pronounced pyroelectric responses and efficiently catalyzed the cycloaddition of CO₂ with propargylamine, with Cu-FE-1 achieving a turnover number (TON) of 5064 (a yield of 98%) and Cu-FE-2 reaching 4876 (a yield of 94%). Notably, Cu-FE-2 further enabled the C–O cross-coupling of phenol with aryl bromides under conditions mimicking diurnal temperature variations, delivering diphenyl ether in a yield of 98% (TON = 4742), whereas Cu-FE-1 was inactive. This divergent reactivity underscores the critical role of structural polarization and coordination flexibility in dictating thermally induced catalytic pathways. Overall, this work introduces a new paradigm of thermal fluctuation-driven catalysis based on molecular ferroelectrics, offering programmable and tunable access to multiple reaction types under mild and field-free conditions.

Manipulation of ferroelectric domains is essential for advancing ferroelectric electronics. Mechanical switching offers an effective route for nanoscale domain control, yet conventional inorganic ferroelectrics typically require micronewton-level forces applied by nanoscale probes, generating GPa local pressures that risk material damage and make it challenging to mechanically generate large-area ferroelectric domain patterns. Overcoming this limitation demands ferroelectrics capable of responding to extremely small mechanical stimuli. Here, we demonstrate ultralow-force-driven polarization switching in the molecular ferroelectric (3,3-difluorocyclobutylammonium)₂CuCl₄, a two-dimensional organic-inorganic hybrid perovskite. Domain switching is achieved with an applied force of only 25 nN—corresponding to a local pressure below 20 MPa, orders of magnitude lower than that required for inorganic oxide ferroelectrics. This exceptionally low mechanical threshold arises from the intrinsic structural compliance and flexibility of molecular ferroelectrics. Moreover, the remarkably small switching force also enables ultrasound-driven domain modification. These results create new opportunities for molecular ferroelectrics in mechanoelectrical electronics, energy harvesting, and ultrasonic catalysis.