Undecacarbonyl-1κ3 C,2κ4 C,3κ4 C-[tris(3-chlorophenyl)phosphine-1κP]-triangulo-triruthenium(0)

In the title triangulo-triruthenium compound, [Ru3(C18H12Cl3P)(CO)11], one equatorial carbonyl group has been substituted by the monodentate phosphine ligand, leaving one equatorial and two axial carbonyl substituents on the Ru atom. The remaining two Ru atoms each carry two equatorial and two axial terminal carbonyl ligands. The three benzene rings make dihedral angles of 87.83 (17), 69.91 (17) and 68.26 (17)° with each other. In the crystal structure, molecules are linked into dimers by intermolecular C—H⋯O hydrogen bonds. The molecular structure is stabilized by an intramolecular C—H⋯O hydrogen bond.

In the title triangulo-triruthenium compound, [Ru 3 (C 18 H 12 -Cl 3 P)(CO) 11 ], one equatorial carbonyl group has been substituted by the monodentate phosphine ligand, leaving one equatorial and two axial carbonyl substituents on the Ru atom. The remaining two Ru atoms each carry two equatorial and two axial terminal carbonyl ligands. The three benzene rings make dihedral angles of 87.83 (17), 69.91 (17) and 68.26 (17) with each other. In the crystal structure, molecules are linked into dimers by intermolecular C-HÁ Á ÁO hydrogen bonds. The molecular structure is stabilized by an intramolecular C-HÁ Á ÁO hydrogen bond.

Related literature
For related structures, see: Bruce et al. (1988); Churchill et al. (1977). For the synthesis, see: Bruce et al. (1987). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ2762).

Undecacarbonyl-1 3 C,2 4 C,3 4 C-[tris(3-chlorophenyl)phosphine-1 P]-triangulo-triruthenium(0)
O. bin Shawkataly, M. A. A. Pankhi, C. S. Yeap and H.-K. Fun Comment Syntheses and structures of substituted triangulo-triruthenium clusters have been of interest to researchers due to observed structural variations and their potential catalytic activity. As part of our ongoing studies on phosphine substituted triangulotriruthenium clusters, herein we report the structure of title compound (I).
In the title compound (I), the monodentate phosphine ligand has replaced a single carbonyl group in the equatorial plane of the Ru 3 triangle. The triangulo-triruthenium is bonded equatorially to a monodentate phosphine ligand. The Ru1-Ru2 bond is noticeably longer [2.9002 (4) Å] compared to the other two Ru-Ru bonds [2.8600 (3) and 2.8611 (4) Å]. The unusual increase in the length of Ru-Ru bond in comparison to those in Ru 3 (CO) 12 (Churchill et al., 1977), can be attributed to the steric effect induced by the bulky substituent.
As observed in Ru 3 (CO) 12 , the bond from metal atoms to the axial CO ligands in complex (I) are longer (Ru-C(ave) = 1.934 Å) compared to the equatorial CO groups (Ru-C(ave) = 1.918 Å). The equatorial Ru-C-O substituents are linear (average value: 177.94°) while the axial Ru-C-O ligands are slightly bent (average value: 173.55°). Similar observations were made by Bruce and co-workers for the range of monosubstituted complexes they synthesized (Bruce et al., 1988).

Experimental
All the manipulations were performed under a dry oxygen-free nitrogen atmosphere using standard Schlenk techniques.
THF was dried over sodium wire and freshly distilled from sodium benzophenone ketyl solution. The title compound (I) was prepared by mixing Ru 3 (CO) 12 (Aldrich) and P(3-Cl-C 6 H 4 ) 3 (Maybridge) in a 1:1 molar ratio in THF at 40 °C. About 0.2 ml of diphenylketyl radical anion initiator (synthesized as per the method of Bruce et al., 1987)  Crystals suitable for X-ray diffraction were grown from n-pentane solution at 10°C.

Refinement
All hydrogen atoms were positioned geometrically and refined using a riding model with C-H = 0.93 Å and U iso (H) = 1.2 U eq (C). Fig. 1. The molecular structure of the title compound with 50% probability ellipsoids for non-H atoms.

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > σ(F 2 ) is used only for calculating Rfactors(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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )