Acta Cryst. (2004). E60, m381±m383 DOI: 10.1107/S1600536804005070 T. D. Keene et al.  [Co(CO 3 )(C 4 H 11 N) 4 ](C 5 H 10 NO 2 )2H 2 O m381 metal-organic papers Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368 Tetra-n-butylamine(carbonato-j 2 O,O 0 )cobalt(III) n-butylcarbamate dihydrate Tony D. Keene, Michael B. Hursthouse and Daniel J. Price* School of Chemistry, University of South- ampton, Highfield, Southampton SO17 1BJ, England Correspondence e-mail: daniel.price@soton.ac.uk Key indicators Single-crystal X-ray study T = 120 K Mean (C±C) = 0.003 A Ê R factor = 0.041 wR factor = 0.108 Data-to-parameter ratio = 21.2 For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e. # 2004 International Union of Crystallography Printed in Great Britain ± all rights reserved The title compound, [Co(CO 3 )(C 4 H 11 N) 4 ](C 5 H 10 NO 2 )2H 2 O, is a coordination complex with an N 4 O 2 coordination sphere around the central Co III ion. The small bite angle of the chelating carbonate causes a distortion of the octahedral geometry to an approximately C 2v local symmetry. Hydrogen- bonding between the carbonate, carbamate and amine groups, and the water of crystallization, results in a complex two- dimensional network. Comment The title complex, (I) (Fig. 1), crystallized very slowly from a mixture of cobalt(II) oxalate dihydrate, n-butylamine and water. This synthesis involves the aerobic oxidation of Co II to Co III , which is facilitated by the strong-®eld amine ligands. In addition, the oxalate is oxidized to CO 2 , which is sequestered in this basic reaction mixture and converted into carbonate and n-butylcarbamate. Compound (I) contains monocationic [Co(BuNH 2 ) 4 (CO 3 )] units and non-coordinating n-butylcarbamate anions. The Co III ion has a distorted octahedral coordination environment Received 2 March 2004 Accepted 4 March 2004 Online 20 March 2004 Figure 1 A view of the asymmetric unit of (I), with displacement ellipsoids drawn at the 50% probability level. Alkyl H atoms have been omitted for clarity. Hydrogen bonds are shown as dashed lines.