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Crystal chemistry of synthetic Co- and Ni-analogues of natrochalcite; the shortest known hydrogen bonds among mineral-type compounds; Part I, Single-crystal X-ray structures

Robert Krickl and Manfred Wildner
Crystal chemistry of synthetic Co- and Ni-analogues of natrochalcite; the shortest known hydrogen bonds among mineral-type compounds; Part I, Single-crystal X-ray structures
European Journal of Mineralogy (December 2007) 19 (6): 805-816

Abstract

Four new representatives of the natrochalcite structure type s.s. - A (super +) Me (sub 2) (super 2+) (X (super 6+) O (sub 4) ) (sub 2) [(H (sub 2) O)(OH)], monoclinic, space group C2/m, Z = 2- with Me (super 2+) = Co or Ni were synthesised under low-hydrothermal conditions and their crystal structures were refined from single-crystal X-ray diffraction data up to sin theta /lambda = 0.904, measured at room temperature and for two compounds also at 105 K. Room temperature data are: NaNi (sub 2) (SO (sub 4) ) (sub 2) [(H (sub 2) O)(OH)]: a = 8.605(1), b = 6.185(1), c = 7.336(1) Aa, beta = 114.78(1) degrees , V = 354.5 Aa (super 3) , R1 = 0.021; NaCo (sub 2) (SO (sub 4) ) (sub 2) [(H (sub 2) O)(OH)]: a = 8.677(1), b = 6.317(1), c = 7.396(1) Aa, beta = 115.40(1) degrees , V = 366.2 Aa (super 3) , R1 = 0.022; NaCo (sub 2) (SeO (sub 4) ) (sub 2) [(H (sub 2) O)(OH)]: a = 8.939(2), b = 6.382(2), c = 7.554(2) Aa, beta = 115.09(1) degrees , V = 390.2 Aa (super 3) , R1 = 0.023; KCo (sub 2) (SeO (sub 4) ) (sub 2) [(H (sub 2) O)(OH)]: a = 9.078(1), b = 6.471(1), c = 7.687(1) Aa, beta = 113.99(1) degrees , V = 412.6 Aa (super 3) , R1 = 0.019. The structure type is built up from chains of edge-sharing MeO (sub 6) octahedra, which are connected by XO (sub 4) tetrahedra and very strong hydrogen bonds to {Me (sub 2) (XO (sub 4) ) (sub 2) [(OH)(H (sub 2) O)]} (super -) sheets. The linkage between these sheets is accomplished by the larger A cations and intermediate to weak hydrogen bonds. Natrochalcite-type compounds are of particular interest due to the occurrence of formal H (sub 3) O (sub 2) (super -) units forming very strong intramolecular hydrogen bonds, e.g. O...O = 2.44 Aa in natrochalcite itself, NaCu (sub 2) (SO (sub 4) ) (sub 2) [(H (sub 2) O)(OH)]. The replacement of Jahn-Teller distorted Cu (super 2+) cations by Co (super 2+) or Ni (super 2+) in the title compounds leads to substantial changes of the MeO (sub 6) coordination polyhedra and, as further consequences, to increased distortions of the XO (sub 4) and AO (sub 8) polyhedra, to the occurrence of short interpolyhedral O...O contacts, and to a further shortening of the strong intramolecular hydrogen bond to O...O = 2.429(2) Aa in NaCo (sub 2) (SO (sub 4) ) (sub 2) [(H (sub 2) O)(OH)] and 2.420(2) Aa in NaNi (sub 2) (SO (sub 4) ) (sub 2) [(H (sub 2) O)(OH)]. These seem to be the shortest hydrogen bond lengths hitherto reported for minerals or mineral-type compounds with fully occupied oxygen donor-acceptor positions. Despite of this fact, the X-ray data corroborate a non-centric, i.e. split position of the hydrogen atom along these short donor-acceptor lines.


ISSN: 0935-1221
EISSN: 1617-4011
Serial Title: European Journal of Mineralogy
Serial Volume: 19
Serial Issue: 6
Title: Crystal chemistry of synthetic Co- and Ni-analogues of natrochalcite; the shortest known hydrogen bonds among mineral-type compounds; Part I, Single-crystal X-ray structures
Affiliation: Universitaet Wien, Institut fuer Mineralogie und Kristallographie, Vienna, Austria
Pages: 805-816
Published: 200712
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Federal Republic of Germany
References: 58
Accession Number: 2008-028868
Categories: Mineralogy of non-silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 7 tables
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, copyright, Schweizerbart'sche Verlagsbuchhandlung. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 200809
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