Crystal structure of bis(dimethylammonium) hexaaquacobalt(II) bis(sulfate) dihydrate

The title salt, (C2H8N)2[Co(H2O)6)](SO4)2·2H2O, is isotypic with (C2H8N)2[Ni(H2O)6)](SO4)2·2H2O. The Co—O bond lengths in the [Co(H2O)6]2+ complex cation show very similar distances as in the related Tutton salt (NH4)2[Co(H2O)6)](SO4)2 [average 2.093 (17) Å], but are significantly longer than in the...

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Bibliographic Details
Main Author: Peter Held
Format: Article
Language:English
Published: International Union of Crystallography 2015-04-01
Series:Acta Crystallographica Section E: Crystallographic Communications
Subjects:
Online Access:http://scripts.iucr.org/cgi-bin/paper?S2056989015003400
Description
Summary:The title salt, (C2H8N)2[Co(H2O)6)](SO4)2·2H2O, is isotypic with (C2H8N)2[Ni(H2O)6)](SO4)2·2H2O. The Co—O bond lengths in the [Co(H2O)6]2+ complex cation show very similar distances as in the related Tutton salt (NH4)2[Co(H2O)6)](SO4)2 [average 2.093 (17) Å], but are significantly longer than in the isotypic NiII compound (Δd ≃ 0.04 Å). The cobalt cation reaches an overall bond-valence sum of 1.97 valence units. The S—O distances are nearly equal, ranging from 1.454 (4) to 1.470 (3) Å [mean 1.465 (12) Å]; however, the O—S—O angles vary clearly from 108.1 (2) to 110.2 (2)° [average bond angle 109.5 (9)°]. The non-coordinating water molecules and dimethylammonium cations connect the sulfate tetrahedra and the [Co(H2O)6]2+ octahedron via O—H...O and N—H...O hydrogen bonds of weak up to medium strength into a three-dimensional framework whereby the complex metal cations and sulfate anions are arranged in sheets parallel to (001).
ISSN:2056-9890