(2-Aminoethanethiolato-κ2 N,S)bis[1,2-bis(diphenylphosphanyl)ethane-κ2 P,P′]ruthenium(II) hexafluoridophosphate

In the crystal of the title compound, [Ru(C2H6NS)(C26H24P2)2]PF6, the RuII atom is in a slightly distorted octahedral geometry, coordinated by one 2-aminoethanethiolate (aet) and two 1,2-bis(diphenylphosphanyl)ethane (dppe) ligands. The crystal consists of a pair of enantiomers (Δ and Λ) of the compound. The Δ and Λ isomers have the λ and δ conformations for the aet chelate rings and the δ and λ conformations for the dppe chelate rings. The F atoms of the PF6 − counter-anion are disordered over three positions, with site occupancies of 0.4, 0.3 and 0.3.

The reaction of [RuCl 2 (dppe) 2 ] (Bautista et al., 1991) with excess Haet in methanol in the presence of NH 4 PF 6 gave a yellow powder of [Ru(aet)(dppe) 2 ]PF 6 . Single-crystals suitable for X-ray analysis were obtained by the recrystallization of the yellow powder from methanol.
The compound crystallized in a non-centrosymmetric space group Cc, the asymmetric unit of which contains one complex cation and one PF 6anion. The Ru atom is in an NP 4 S octahedral geometry coordinated by two dppe-κP,P and one aet-κN,S ligands (Fig. 1). The Ru-S [2.431 (2) Å] and Ru-N [2.212 (5) Å] bond distances are slightly longer than those of the related ruthenium(II) complexes with aet ligand(s) (Ru-S = 2.291-2.394 Å, Ru-N = 2.133-2.212 Å) (Tamura et al., 2007;Matsuura et al., 2006;Hanif et al., 1999). On the other hand, the Ru-P bond distances (average 2.380 Å) are similar to those of ruthenium(II) complexes with dppe ligands (av. 2.32 Å), as found in the Cambridge Structural Database (Allen, 2002). Consistent with the space group Cc, the crystal consists of a pair of enantiomers (Δ and Λ) of the ruthenium(II) complex. Two dppe P,P-chelate rings in the complex adopt an ob conformation (δ for Δ isomer, λ for Λ isomer), while its N,S-aet chelate ring has a lel conformation (λ for Δ isomer, δ for Λ isomer). It may be interesting to note that no significant specific intermolecular interactions have been found, except for very weak N-H···F interactions between the complex cations and PF 6anions (Fig. 2).

Experimental
To a solution of 0.20 g (0.21 mmol) of [RuCl 2 (dppe) 2 ] in 200 ml of methanol was added 0.078 g (1.01 mmol) of Haet and 0.338 g (2.07 mmol) of NH 4 PF 6 . The mixture was stirred at room temperature for 1 h. The resulting yellow suspension was concentrated to dryness with a rotary evaporator. The residue was washed with water to give a yellow powder of Single crystals of [Ru(aet)(dppe) 2 ]PF 6 suitable for X-ray analysis were obtained by the recrystallization of a yellow powder from methanol at room temperature.

Figure 1
A view of the molecular structure of [Ru(aet)(dppe) 2 ]PF 6 with the atom-numbering scheme. H atoms and F atoms of the PF 6with minor occupancies were omitted for clarity. Ellipsoids represent 50% probability.

Figure 2
Crystal packing of [Ru(aet)(dppe) 2 ]PF 6 viewed along the y axis. F atoms of the PF 6with minor occupancies were omitted for clarity.

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. 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 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.