(2,2′-Bipyridine-κ2 N,N′)chlorido(1,4,7-trithiacyclononane-κ3 S,S′,S′′)ruthenium(II) nitrate monohydrate

In the title compound, [RuCl(C10H8N2)(C6H12S3)]NO3·H2O or [RuCl(bpy)([9]aneS3)]NO3·H2O, ([9]aneS3 is 1,4,7-trithiacyclononane and bpy is 2,2′-bipyridine), the RuII cation has a slightly distorted octahedral environment composed of three facially coordinated S atoms from ([9]aneS3), two N atoms from bpy and a chloride anion. The nitrate counter-ion and the water molecule of crystallization are engaged in O—H⋯O hydrogen-bonding interactions, leading to a supramolecular chain running parallel to the c axis.

We are grateful to the Fundaçã o para a Ciê ncia e a Tecnologia (FCT, Portugal) for their general financial support, for the post-doctoral research grant No. SFRH/BPD/63736/ 2009 (to JAF), for funding the BII programme and for specific funding toward the purchase of the single-crystal diffractometer.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: BG2373).

Comment
The ruthenium coordination complexes containing 1,4,7-trithiacyclonane ([9]aneS 3 ) have been studied for their activity as antitumoral agents (Bratsos et al., 2008;Serli et al., 2005). Some members of this family of compounds have been tested as cytotoxic ) and antimicrobial  agents, or as catalysts (Sala et al., 2004). We have also studied the solid-state properties of the inclusion compounds of a number of these ruthenium compounds in cyclodextrins (Marques et al., 2008). While reacting the Ru II precursor [Ru ([9]aneS 3 )(bpy)Cl]Cl with AgNO 3 we isolated the title compound as a secondary product.
The asymmetric unit of the title compound (see Scheme) comprises a whole [Ru ([9]aneS 3 )(bpy)Cl] + cation, a chargebalancing nitrate anion and a water molecule of crystallization ( Figure 1). A survey in the Cambridge Structural Database revealed that this Ru II cation has already been described by other groups while co-crystallizing with different anions, namely chloride and trifluoromethanesulfonate (Serli et al., 2005;Goodfellow et al., 1997). This cation has an octahedral coordination environment for Ru II with the tricoordinating [9]aneS 3 molecule occupying one of the faces of the polyhedron [Ru-S distances ranging from 2.2800 (9) to 2.4379 (8)  The water molecule of crystallization and the charge-balancing nitrate anion interact via strong hydrogen bonds (Table 1), leading to a polymeric H1Y-{O1W-H1X···O3-N3-O2···H1Y} ∞ chain running parallel to the c-axis (dashed pink lines in Figure 2), which can be described by a C 2 2 graph set motif (Grell et al., 1999). Noteworthy, these hydrogen bonds are of strong nature [O···O distances of 3.037 (4) and 2.839 (4) Å] and highly directional [O-H···O angles of 169 (4) and 166 (4)°].
The title compound, based on the [Ru ([9]aneS 3 )(bpy)Cl] + cation, is considerably different from the two previously related structures: while in our structure the charge-balancing nitrate co-crystallizes with one water molecule, the chloride and trifluoromethanesulfonate structures contain three and none of these entities, respectively (Goodfellow et al., 1997;Serli et al., 2005). Noteworthy, in the former structure (having three water molecules) the crystal packing exhibits a supramolecular two-dimensional network of hydrogen bonding interactions. In the title compound the presence of a single water molecule in the composition promotes the formation of only a one-dimensional supramolecular chain (see above). In summary, it is feasible to consider the title compound as an intermediary case between the two already known structures.
Remaining chemicals were purchased from commercial sources and used as received without further purification.
[Ru ([9]aneS 3 )(bpy)Cl]Cl (105.6 mg; 0.21 mmol) was treated with AgNO 3 (53.0 mg; 0.31 mmol) in order to produce an intermediate labile species by exchanging the coordinated Clligand by a solvent molecule (20 minutes stirring at room temperature in 50 ml of commercial grade ethanol). A white precipitate (AgCl) was filtered off through Celite, and the volume of the remaining red-orange solution was reduced to half by evaporation at 50 °C in a rotatory evaporator. After one month at -18 °C, the title compound was isolated as orange crystals.

Refinement
Hydrogen atoms bound to carbon were located at their idealized positions and were included in the final structural model in riding approximation with C-H = 0.95 Å (aromatic C-H) and 0.99 Å (-CH 2 ). The isotropic thermal displacement parameters for these atoms were fixed at 1.2 times U eq of the respective parent carbon atom.
Hydrogen atoms associated with the water molecule of crystallization have been directly located from difference Fourier maps and were included in the final structural model with the distances restrained to 0.95 (1) Å and U iso =1.5×U eq of the respective parent oxygen atom. Fig. 1. Asymmetric unit of the title compound. Non-hydrogen atoms are represented as thermal ellipsoids drawn at the 50% probability level while hydrogen atoms are drawn as small spheres with arbitrary radii. The labelling scheme is provided for all non-hydrogen atoms.  Table 1.