Local Chiral Inversion of Thymine Dimers by Manipulating SingleWater Molecules

Water, as one of the most important and indispensable small molecules in vivo, plays a crucial role in drivingbiological self-assembly processes. Real-space detection and identification of water-induced organic structures and further capture ofdynamic dehydration processes are important yet challenging, which would help to reveal the cooperation and competitionmechanisms among water-involved noncovalent interactions. Herein, introduction of water molecules onto the self-assembledthymine (T) structures under ultrahigh vacuum (UHV) conditions results in the hydration of hydrogen-bonded T dimers forming awell-ordered water-involved T structure. Reversibly, a local dehydration process is achieved byin situscanning tunneling microscopy(STM) manipulation on single water molecules, where the adjacent T dimers connected with water molecules undergo a local chiralinversion process with the hydrogen-bonding configuration preserved. Such a strategy enables real-space identification and detectionof the interactions between water and organic molecules, which may also shed light on the understanding of biologically relevant self-assembly processes driven by water.

Automated summary

Water plays a crucial role in biological self-assembly processes, and studying the interactions between water and organic molecules can provide insights into the mechanisms of biological self-assembly.