Two-Dimensional Water and Ice Layers:  Neutron Diffraction Studies at 278, 263, and 20 K

• Published in: Journal of the American Chemical Society Vol. 124; no. 47; pp. 14010 - 14011
• Main Authors: Janiak, Christoph, Scharmann, Tobias G, Mason, Sax A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 27.11.2002
• Subjects: Chelating Agents - chemistry; Cold Temperature; Condensed matter: structure, mechanical and thermal properties; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Ice; Neutron Diffraction; Nickel - chemistry; Organometallic Compounds - chemistry; Physics; Specific phase transitions; Structure of liquids; Structure of simple liquids; Structure of solids and liquids; crystallography; Water - chemistry; Polycrystalline ice; Temperature dependence; Solid-state phase transformations; Aqueous solutions; Solution structure; Neutron diffraction; Solid-liquid transformations; Two dimensional structure; Experimental study; Honeycomb structures
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja0274608

Neutron diffraction elucidates the structures of two-dimensional (2D) water layers (278 K) or 2D ice layers confined in an organic slit-shaped nanospace. The two-dimensional ice phases reported here consist of individual eight-membered rings or folded-chain segments (263 K) and condensed twelve-membered irregular rings (20 K). This is quite different from bulk or other 2D ice structures; the latter usually form hexagonal honeycomb lattices. Both low-temperature structures typically feature water molecules which are surrounded by two or three other water molecules. Neutron diffraction and thermochemical studies indicate a liquid−solid-phase transition around 277 K for two-dimensional D2O layers. A further solid−solid-phase transition occurs between 263 and 20 K.