Horst Schmidt, Iris Paschke, Daniela Freyer, Wolfgang Voigt
{"title":"Water channel structure of bassanite at high air humidity: crystal structure of CaSO4·0.625H2O.","authors":"Horst Schmidt, Iris Paschke, Daniela Freyer, Wolfgang Voigt","doi":"10.1107/S0108768111041759","DOIUrl":null,"url":null,"abstract":"<p><p>Structure analysis using single-crystal diffraction was carried out as a contribution to the dispute about the nature of the water channel structure of bassanite (CaSO(4)·0.5H(2)O). A recent result of Weiss & Bräu (2009) for the crystal structure of bassanite (monoclinic, space group C2) at ambient conditions of air humidity was confirmed. In the presence of high relative air humidity the crystal structure of bassanite transformed due to the incorporation of additional water of hydration. The crystal structure of CaSO(4)·0.625H(2)O was solved by single-crystal diffraction at 298 K and 75% relative air humidity. The experimental results provided an insight into both crystal structures. A model explaining the phase transition from CaSO(4)·0.625H(2)O to CaSO(4)·0.5H(2)O was derived. The monoclinic cell setting of CaSO(4)·0.5H(2)O and the trigonal cell setting of CaSO(4)·0.625H(2)O were confirmed by powder diffraction.</p>","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"67 Pt 6","pages":"467-75"},"PeriodicalIF":1.9000,"publicationDate":"2011-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768111041759","citationCount":"29","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Crystallographica Section B-structural Science","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1107/S0108768111041759","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2011/11/17 0:00:00","PubModel":"Epub","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 29
Abstract
Structure analysis using single-crystal diffraction was carried out as a contribution to the dispute about the nature of the water channel structure of bassanite (CaSO(4)·0.5H(2)O). A recent result of Weiss & Bräu (2009) for the crystal structure of bassanite (monoclinic, space group C2) at ambient conditions of air humidity was confirmed. In the presence of high relative air humidity the crystal structure of bassanite transformed due to the incorporation of additional water of hydration. The crystal structure of CaSO(4)·0.625H(2)O was solved by single-crystal diffraction at 298 K and 75% relative air humidity. The experimental results provided an insight into both crystal structures. A model explaining the phase transition from CaSO(4)·0.625H(2)O to CaSO(4)·0.5H(2)O was derived. The monoclinic cell setting of CaSO(4)·0.5H(2)O and the trigonal cell setting of CaSO(4)·0.625H(2)O were confirmed by powder diffraction.
期刊介绍:
Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials publishes scientific articles related to the structural science of compounds and materials in the widest sense. Knowledge of the arrangements of atoms, including their temporal variations and dependencies on temperature and pressure, is often the key to understanding physical and chemical phenomena and is crucial for the design of new materials and supramolecular devices. Acta Crystallographica B is the forum for the publication of such contributions. Scientific developments based on experimental studies as well as those based on theoretical approaches, including crystal-structure prediction, structure-property relations and the use of databases of crystal structures, are published.