Bioinorganic Chemistry and Applications
Volume 2007 (2007), Article ID 51567, 7 pages
doi:10.1155/2007/51567
Research Article

Synthesis, X-Ray Structure, and Characterization of a Complex Containing the Hexakis(urea)cobalt(II) Cation and Lattice Urea Molecules

Labrini Drakopoulou,1 Constantina Papatriantafyllopoulou,1 Aris Terzis,2 Spyros P. Perlepes,1 Evy Manessi-Zoupa,1 and Giannis S. Papaefstathiou3

1Department of Chemistry, University of Patras, Patras 265 04, Greece
2Institute of Materials Science, National Centre of Scientific Research “Demokritos”, Agia Paraskevi Attikis 153 10, Greece
3Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, Zografou 157 71, Greece

Received 28 August 2007; Accepted 10 November 2007

Academic Editor: Osamu Yamauchi

Copyright © 2007 Labrini Drakopoulou et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The 12: 1 reaction of urea (U) with CoI2 in EtOH yielded the “clathrate-coordination” compound [CoU6]I2·4U (1). The complex crystallizes in the monoclinic space group P21/c. The lattice constants are a = 9.844(4), b = 7.268(3), c = 24.12(1) Å, and β=98.12(1)∘. The crystal structure determination demonstrates the existence of octahedral [CoU6]2+ cations, I- counterions, and two different types (two U1 and two U2) of hydrogen-bonded, lattice urea molecules. The [CoU6]2+ cations and the U1 lattice molecules form two-dimensional hydrogen-bonded layers which are parallel to the ab plane. The I- anions are placed above and below each layer, and are hydrogen bonded both to U1 molecules and [CoU6]2+ cations. Each U2 molecule is connected to a [CoU6]2+ cation through an N–H⋯O hydrogen bond resulting in a three-dimensional network. Room temperature magnetic susceptibility and spectroscopic (solid-state UV/Vis, IR, Raman) data of 1 are discussed in terms of the nature of bonding and the known structure.