Janiak Christoph, Scharmann Tobias G, Mason Sax A
Institut für Anorganische und Analytische Chemie, Universität Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany.
J Am Chem Soc. 2002 Nov 27;124(47):14010-1. 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.
中子衍射阐明了限制在有机狭缝形纳米空间中的二维（2D）水层（278 K）或二维冰层的结构。这里报道的二维冰相由单个八元环或折叠链段（263 K）以及凝聚的十二元不规则环（20 K）组成。这与块状或其他二维冰结构有很大不同；后者通常形成六边形蜂窝晶格。这两种低温结构的典型特征是水分子被另外两个或三个水分子包围。中子衍射和热化学研究表明，二维D2O层在277 K左右发生液-固相变。在263 K和20 K之间发生进一步的固-固相变。
