CO2 Induces Symmetry Breaking in Layered Dipeptide Crystals

Control of symmetry breaking of materials provides large opportunities to regulate their properties and functions. Herein, we report breaking the symmetry of layered dipeptide crystals by utilizing CO2 to induce the adjacent monomolecular layers to stack from the opposite to the same direction. The role of CO2 is to cover the interlayer interaction sites and force the dipeptides to adsorb at asymmetric positions. Further, the dipeptide crystals exhibit far superior piezoelectricity after symmetry breaking and the piezoelectric voltage generated from the dipeptide-based generators becomes more than 500 % higher than before. This work reveals a potential route to engineer structures and properties of layered materials and provides a deep insight into the control of non-covalent interactions.

Automated summary

Symmetry of layered dipeptide crystals can be broken by utilizing CO2, which induces adjacent monomolecular layers to stack in the same direction. CO2 covers the interlayer interaction sites, forcing the dipeptides to adsorb asymmetrically. The dipeptide crystals exhibit enhanced piezoelectricity and the piezoelectric voltage generated from dipeptide-based generators is increased by more than 500% after symmetry breaking. This work provides a potential route to engineer structures and properties of layered materials, and offers insights into the control of non-covalent interactions.