biostudies-literatureCai SAcademy of FinlandH2020 Marie Sklodowska-Curie ActionsEuropean Research CouncilMinistry of Education, Culture, Sports, Science and Technology20227-20231https://www.ebi.ac.uk/biostudies/studies/S-EPMC9650709biostudies-literatureUnknown144(44)The existence of water dimers in equilibrium water vapor at room temperature and their anomalous properties revealed by recent studies suggest the benchmark role of water dimers in both experiment and theory. However, there has been a limited observation of individual water dimers due to the challenge of water separation and generation at the single-molecule level. Here, we achieve real-space imaging of individual confined water dimers embedded inside a self-assembled layer of a DNA base, adenine, on Ag(111). The hydration of the adenine layers by these water dimers causes a local surface chiral inversion in such a way that the neighboring homochiral adenine molecules become heterochiral after hydration, resulting in a mismatched hydrogen-bond pattern between neighboring adenine molecules.Journal of the American Chemical SocietyWater Dimer-Driven DNA Base Superstructure with Mismatched Hydrogen Bonding.PMC9650709345066897828284621347319318995346824314862347611788185Foster ASKurki LCai SXu CLiljeroth PfalseWater Dimer-Driven DNA Base Superstructure with Mismatched Hydrogen Bonding.The existence of water dimers in equilibrium water vapor at room temperature and their anomalous properties revealed by recent studies suggest the benchmark role of water dimers in both experiment and theory. However, there has been a limited observation of individual water dimers due to the challenge of water separation and generation at the single-molecule level. Here, we achieve real-space imaging of individual confined water dimers embedded inside a self-assembled layer of a DNA base, adenine, on Ag(111). The hydration of the adenine layers by these water dimers causes a local surface chiral inversion in such a way that the neighboring homochiral adenine molecules become heterochiral after hydration, resulting in a mismatched hydrogen-bond pattern between neighboring adenine molecules.2022-01-01T00:00:00Z2022 Nov2025-04-04T09:02:36.004Z2025-04-04T09:02:36.004ZS-EPMC96507093630168710.1021/jacs.2c09575