(N-Benzoyl-N′,N′-diphenylthioureato-κ2 S,O)(η4-cycloocta-1,5-diene)rhodium(I)

The title complex, [Rh(C20H15N2OS)(C8H12)], exhibits an essentially square-planar coordination environment around the RhI atom, which bears a bidentate cyclooctadiene ligand as well as a monoanionic bidentate benzoylthioureate ligand. The RhI atom, the S- and O-donor atoms and the alkene centroids of the cyclooctadiene ligand do not deviate by more than 0.031 Å from their least mean-squares plane.

The title complex, [Rh(C 20 H 15 N 2 OS)(C 8 H 12 )], exhibits an essentially square-planar coordination environment around the Rh I atom, which bears a bidentate cyclooctadiene ligand as well as a monoanionic bidentate benzoylthioureate ligand. The Rh I atom, the S-and O-donor atoms and the alkene centroids of the cyclooctadiene ligand do not deviate by more than 0.031 Å from their least mean-squares plane.
The title compound [Rh(C 8 H 12 )(C 20 H 15 N 2 OS)], (I), bears a benzoyl-functionalized thioureato moiety (Arslan et al., 2003), which can coordinate as a mono-or a bidentate ligand, depending on the metal and the other ligands present. With this specific ligand class, it was found that the peripheral substitution pattern significantly influences the coordination behaviour. When an N,N′,N′-trisubstituted thiourea ligand was employed, as is the case in this study, the thiourea coordinates as a monoanionic bidentate ligand, whereas an N,N′-disubstituted thiourea coordinates only through its sulfur-atom as a neutral monodentate ligand which is stabilized through intramolecular hydrogen bonding (Cauzzi et al., 1995;Kotze et al., 2010). One of these hydrogen bonds ensures that the sulfur and oxygen atoms are in a mutual transposition, which stabilizes the pre-ligand in such a way that bidentate coordination is prevented. In the trisubstituted variation used in this study, this intramolecular interaction is not possible (Hernandez et al., 2003), which enables the ligand to coordinate through its sulfur and oxygen atoms simultaneously. This structural report is only the third in which a rhodium complex bears both cyclooctadiene and S,O-bidentate ligands (Grim et al., 1991;Hesp et al., 2007).
The geometric parameters show that the rhodium(I) atom in the title compound has an essentially square planar coordination sphere. The deviation of the rhodium ion from the least mean squares plane, defined by the rhodium, oxygen and sulfur atoms and the centroids of the cyclooctadiene alkene bonds, is 0.001 Å. The donor atoms of the thioureato ligand and the centroids do not deviate more than 0.031 and 0.011 Å, respectively. The S,O-ligand exhibits a bite angle of 92.60 (5)°, and the cyclooctadiene ligand shows a bite angle of 87.90 (8)°. The bond lengths of the ligands to rhodium are all within the expected range for a compound of this type. The monoanionic ligand shows electron delocalization so that the bond lengths fall between those of single and double C-O, C-S and C-N bonds. There are no significant intermolecular interactions.

Experimental
The title compound was prepared by adding 0.4 mmol of N-benzoyl-N,N′-diphenyl thiourea to a suspension of 0.

Refinement
The hydrogen atoms were added geometrically and refined as riding on their parent atoms, with C-H distances of 0.95 Å for phenyl H atoms, of 1.00 Å for those bonded to sp 2 C atoms and of 0.99 Å for those bonded to sp 2 C atoms of the cyclooctadiene ligand. The thermal displacement coefficients U iso (H) were set to 1.2U eq (C) of the corresponding parent atoms.

Figure 1
Molecular structure of (I). Displacement ellipsoids are drawn at the 50% probability level. H-atoms have been omitted for clarity. Special details Experimental. The intensity data was collected on a Bruker X8 ApexII 4 K Kappa CCD diffractometer using an exposure time of 10 s/frame. A total of 1166 frames was collected with a frame width of 0.5° covering up to θ = 28.00° with 98.3% completeness accomplished. Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.