Acta Cryst. (2010). B66, 430-440 [ doi:10.1107/S0108768110020410 ]
Abstract: Attempts to prepare the compound [Ni(H2O)2(15-crown-5)](X)2 were eventually successful with X = NO
provided that a synthetic route aimed at restricting water was followed. Application of this method was extended to make the analogous compound with X = HSO
, for which three symmetry-related phases were isolated between 295 and 110 K: a room-temperature phase with Z' = ½ [phase (I)], an intermediate-temperature phase with Z' = 1 [phase (II)] and a low-temperature phase with Z' = 2 [phase (III)]. The phases are related by two reversible solid-solid phase transitions, and both transitions take place without a significant loss of crystallinity. In the phase sequence (I) ![[left right arrow]](/logos/entities/harr_rmgif.gif)
(II) (III) (Z': ½ 1 2), the crystal packing remains remarkably similar but the degree of order in the crystal changes significantly; the structure is very disordered at room and intermediate temperatures but is ordered at 110 K. The compound [Ni(H2O)2(15-crown-5)](HSO4)2 has a complicated hydrogen-bonding network, which contains O-H
O bonds between the counterions. Structural changes are largest along some face-diagonal directions in the sequence (I) (II) (III).
Keywords: Ni coordination; phase transitions; phase sequence; hydrogen bonding.
 |   Structure factor file (CIF format) (106.3 kbytes) |
| Structure factor file (CIF format) (218.5 kbytes) |
| Structure factor file (CIF format) (426.6 kbytes) |
To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.
The download button will force most browsers to prompt for a file name to store the data on your hard disk.
Where possible, images are represented by thumbnails.
Copyright © International Union of Crystallography
IUCr Webmaster