Overview

• Tokyo University of Science researchers directly characterized a premelting state of confined water using static solid‑state 2H NMR.
• Water inside ~1.6 nm quasi‑one‑dimensional channels of a molecular crystal loaded with D2O organized into a hierarchical three‑layer structure.
• Gradual heating showed incompletely hydrogen‑bonded layers melting before fully frozen layers, producing coexisting frozen and mobile water.
• Spin–lattice relaxation data showed rotational correlation times close to bulk liquid water despite solid‑like positional constraints.
• The peer‑reviewed findings in JACS (DOI: 10.1021/jacs.5c04573) illuminate confined‑water dynamics relevant to biology and nanofluidics, with proposed applications like gas storage remaining exploratory.