Dichloro ( g 6p-cymene ) ( triphenylphosphine )-ruthenium ( II )

# 2006 International Union of Crystallography All rights reserved The title compound, [Ru(C10H14)Cl2(C18H15P)], crystallizes with two molecules in the asymmetric unit. It adopts the classic pseudo-tetrahedral piano-stool structure. A comparison of the Ru—P, Ru—Cl, Ru—C(av) bond lengths and the sum of the P—Ru—Cl1, P—Ru—Cl2 and Cl1—Ru—Cl2 angles (for both independent molecules) with those of previously determined compounds [( -arene)Ru(PPh3)Cl2] reveals that the nature of the -arene ligand has a marginal effect on these structural parameters.

The title compound, [Ru(C 10 H 14 )Cl 2 (C 18 H 15 P)], crystallizes with two molecules in the asymmetric unit. It adopts the classic pseudo-tetrahedral piano-stool structure. A comparison of the Ru-P, Ru-Cl, Ru-C(av) bond lengths and the sum of the P-Ru-Cl1, P-Ru-Cl2 and Cl1-Ru-Cl2 angles (for both independent molecules) with those of previously determined compounds [( 6 -arene)Ru(PPh 3 )Cl 2 ] reveals that the nature of the 6 -arene ligand has a marginal effect on these structural parameters.
There are two similar molecules in the asymmetric unit, so discussion will primarily focus on one of these independent molecules; see Fig. 1 for a view of one of the two independent molecules. The Ru atom has a typical piano-stool coordination environment, with an 6 -coordinated p-cymene ligand, two chlorides and a triphenylphosphine ligand. Both molecules adopt a conformation half way between staggered and eclipsed orientations with regard to the p-cymene ring and the other three coordinated atoms. The metric parameters around the Ru core (Table 1) compare well with those of similar threelegged piano-stool [( 6 -arene)Ru(PPh 3 )Cl 2 ] complexes (II)-(VI) ( Table 2). The two p-cymene alkyl substituents bend very slightly away from the metal by 0.03 Å at the methyl group and 0.05 Å at the isopropyl group (for molecule 1) and by 0.02 Å at the methyl group and 0.01 Å at the isopropyl group (for molecule 2). The average Ru-C distances are 2.218 (2) and 2.215 (2) Å for the two independent molecules, in the range found in compounds (II)-(VI) [2.202 (3)-2.249 (4) Å ]. There is very little difference in the Ru-C centroid parameters (1.709 and 1.705 Å ) for the two independent molecules in (I).
In summary, we have shown that triphenylphosphine affords a classic pseudo-tetrahedral ( 6 -p-cymene)ruthenium(II) chloro complex with typical Ru-P/Ru-Cl bond lengths and angles.

Experimental
To a CH 3 OH (10 ml) solution of [( 6 -p-cymene)RuCl 2 ] 2 (0.043 g, 0.057 mmol) was added a CH 3 OH (10 ml) solution of Cu[2,3pz(CO 2 )(CO 2 H)](PPh 3 ) 2 (0.018 g, 0.028 mmol) (pz = pyrazine). The dark-orange solution was stirred at room temperature for 2 h. The mixture was evaporated to dryness under reduced pressure, affording a dark-orange solid which was redissolved in the minimum volume of CH 2 Cl 2 (ca 2 ml) and precipitated with diethyl ether (10 ml). The green solid was collected by suction filtration and dried in vacuo. Suitable X-ray quality crystals of (I) were obtained by slow evaporation of the CH 2 Cl 2 /diethyl ether filtrate. )/3 (Á/) max = 0.002 Á max = 0.52 e Å À3 Á min = À0.59 e Å À3 Table 1 Selected bond lengths (Å ). Ru1 The structure of one of the two independent molecules (I), showing the atom-labelling scheme; the other molecule is very similar. Displacement ellipsoids are drawn at the 50% probability level. All H atoms have been omitted for clarity.  H atoms were positioned geometrically (C-H = 0.95 Å for aryl, 0.98 Å for methine and 1.00 Å for methyl H atoms) and refined using a riding model; U iso values were set at 1.2U eq (C) (1.5U eq for methyl H atoms).
Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.