TY - JOUR

T1 - Rapid Water Diffusion at Cryogenic Temperatures through an Inchworm-like Mechanism

AU - Fang, Wei

AU - Meyer auf der Heide, Kastur M.

AU - Zaum, Christopher

AU - Michaelides, Angelos

AU - Morgenstern, Karina

N1 - Funding Information: This work was supported by the Research Training group ‘Confinement-controlled Chemistry’, which is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - GRK2376/331 085 229 and by the DFG under Germany’s Excellence Strategy - EXC-2033 - Projektnummer 390 677 874 RESOLV. We are grateful to the Materials Chemistry Consortium (funded by EPSRC (EP/L000202)) and to the UK Materials and Molecular Modelling Hub (funded by EPSRC (EP/P020194/1 and EP/T022213/1)) for computational resources.

PY - 2022/1/12

Y1 - 2022/1/12

N2 - Water diffusion across the surfaces of materials is of importance to disparate processes such as water purification, ice formation, and more. Despite reports of rapid water diffusion on surfaces the molecular level, details of such processes remain unclear. Here, with scanning tunneling microscopy, we observe structural rearrangements and diffusion of water trimers at unexpectedly low temperatures (<10 K) on a copper surface, temperatures at which water monomers or other clusters do not diffuse. Density functional theory calculations reveal a facile trimer diffusion process involving transformations between elongated and almost cyclic conformers in an inchworm-like manner. These subtle intermolecular reorientations maintain an optimal balance of hydrogen-bonding and water–surface interactions throughout the process. This work shows that the diffusion of hydrogen-bonded clusters can occur at exceedingly low temperatures without the need for hydrogen bond breakage or exchange; findings that will influence Ostwald ripening of ice nanoclusters and hydrogen bonded clusters in general.

AB - Water diffusion across the surfaces of materials is of importance to disparate processes such as water purification, ice formation, and more. Despite reports of rapid water diffusion on surfaces the molecular level, details of such processes remain unclear. Here, with scanning tunneling microscopy, we observe structural rearrangements and diffusion of water trimers at unexpectedly low temperatures (<10 K) on a copper surface, temperatures at which water monomers or other clusters do not diffuse. Density functional theory calculations reveal a facile trimer diffusion process involving transformations between elongated and almost cyclic conformers in an inchworm-like manner. These subtle intermolecular reorientations maintain an optimal balance of hydrogen-bonding and water–surface interactions throughout the process. This work shows that the diffusion of hydrogen-bonded clusters can occur at exceedingly low temperatures without the need for hydrogen bond breakage or exchange; findings that will influence Ostwald ripening of ice nanoclusters and hydrogen bonded clusters in general.

KW - diffusion

KW - hydrogen-bonding

KW - oligomers

KW - Water

UR - http://www.scopus.com/inward/record.url?scp=85122450398&partnerID=8YFLogxK

U2 - 10.48550/arXiv.2112.13549

DO - 10.48550/arXiv.2112.13549

M3 - Article

C2 - 34958578

AN - SCOPUS:85122450398

VL - 22

SP - 340

EP - 346

JO - Nano letters

JF - Nano letters

SN - 1530-6984

IS - 1

ER -