Crystal structure of a high‐pressure phase of magnesium chloride hexahydrate determined by in‐situ X‐ray and neutron diffraction methods. Issue 12 (8th November 2019)

• Record Type: Journal Article
• Authors: Yamashita, Keishiro; Komatsu, Kazuki; Hattori, Takanori; Machida, Shinichi; Kagi, Hiroyuki
• Is Part Of: Acta crystallographica. Volume 75:Issue 12(2019)
• Page Start: 1605
• Page End: 1612
• Publication Date: 2019-11-08
• Subjects: powder diffraction -- salt hydrate -- magnesium chloride -- high pressure -- hydrogen bond -- crystal structure; Crystallography -- Periodicals; Crystals -- Periodicals; 548.3
• DOI: 10.1107/S2053229619014670
• Languages: English
• ISSNs: 2053-2296

Abstract

Abstract : A structural study of a high‐pressure phase of magnesium chloride hexahydrate (MgCl2 ·6H2 O‐II) showed symmetry reduction of the crystal structure from its ambient‐pressure phase. This change is induced by modification of the hydrogen‐bond network. Abstract : A high‐pressure phase of magnesium chloride hexahydrate (MgCl2 ·6H2 O‐II) and its deuterated counterpart (MgCl2 ·6D2 O‐II) have been identified for the first time by in ‐ situ single‐crystal X‐ray and powder neutron diffraction. The crystal structure was analyzed by the Rietveld method for the neutron diffraction pattern based on the initial structure determined by single‐crystal X‐ray diffraction. This high‐pressure phase has a similar framework to that in the known ambient‐pressure phase, but exhibits some structural changes with symmetry reduction caused by a subtle modification in the hydrogen‐bond network around the Mg(H2 O)6 octahedra. These structural features reflect the strain in the high‐pressure phases of MgCl2 hydrates.