Related Experiment Video
Updated: Oct 7, 2025

Microscopic Visualization of Porous Nanographenes Synthesized through a Combination of Solution and On-Surface Chemistry
Published on: March 4, 2021
Anisotropy of the Proton Kinetic Energy as a Tool for Capturing Structural Transition in Water Confined in a Graphene
Mohd Moid1, Yacov Finkelstein2, Raymond Moreh3
1Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India.
Abstract:
The proton dynamics of a 2D water monolayer confined inside a graphene slit pore is studied in Cartesian and molecular frames of reference using molecular dynamics simulations. The vibrational density of states of the proton was calculated versus temperature and was further used to deduce the mean kinetic energy of the hydrogen atoms, Ke(H), in both frames of reference. The directional components of Ke(H) are in good agreement with experimental observations for bulk as well as nanoconfined water. Nonetheless, while in the molecular frame of reference the effect of temperature on the anisotropy ratios of Ke(H) (the ratio between its directional components) are practically invariant between the 2D and 3D cases, those in the Cartesian frame of reference reveal a rather notable reduction across 200 K, indicating the occurrence of an order-disorder transition. This result is further supported by the calculated entropy and enthalpy of the confined water molecules. Overall, it is shown that Ke(H) anisotropy ratios may serve as a valuable order parameter for detecting structural transformations in hydrogen bonds containing molecular systems.
More Related Videos
Related Concept Videos
Proton (¹H) NMR: Chemical Shift
Absorption signals of all the protium nuclei...
¹H NMR of Labile Protons: Temporal Resolution
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
π Electron Effects on Chemical Shift: Overview
¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

