title: Two-dimensional water and ice layers: neutron diffraction studies at 278, 263, and 20 k.
abstract: 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.
authors.affiliation: Institut für Anorganische und Analytische Chemie, Universität Freiburg, Albertstrasse 21, D-79104 Freiburg, Germany. janiak@uni-freiburg.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Janiak
authors.forename: Tobias G
authors.initials: TG
authors.lastname: Scharmann
authors.forename: Sax A
authors.initials: SA
authors.lastname: Mason
mesh_terms: D002614:Chelating Agents / Q000737:chemistry; D003080:Cold Temperature; D007053:Ice; D033363:Neutron Diffraction; D009532:Nickel / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D007053:Ice; D009942:Organometallic Compounds; D014867:Water; D009532:Nickel