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

The 12: 1 reaction of urea (U) with CoI(2) in EtOH yielded the "clathrate-coordination" compound [CoU(6)]I2.4U (1). The complex crystallizes in the monoclinic space group P2(1)/c. The lattice constants are a = 9.844(4), b = 7.268(3), c = 24.12(1) A, and beta=98.12(1) degrees composite function. The crystal structure determination demonstrates the existence of octahedral [CoU6](2+) cations, I(-) counterions, and two different types (two U(1) and two U(2)) of hydrogen-bonded, lattice urea molecules. The [CoU(6)](2+) cations and the U(1) 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 U(1) molecules and [CoU(6)](2+) cations. Each U(2) molecule is connected to a [CoU(6)](2+) cation through an N-Hcdots, three dots, centeredO 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.