2,9-Bis(5-sulfanylidene-4,5-dihydro-1,3,4-oxadiazol-2-yl)-1,10-phenanthroline dimethyl sulfoxide disolvate

In the title compound, C16H8N6O2S2·2C2H6OS, the phenanthroline molecule resides on a twofold axis, and the asymmetric unit also contains a slightly disordered [occupancy ratio for S atom of 0.95 (3):0.047 (3)] molecule of dimethyl sulfoxide. The O atoms of the solvent molecule accept hydrogen bonds from the N—H groups of the five-membered 2,3-dihydro-1,3,4-oxadiazole-2-thione ring. This ring is nearly coplanar with the phenanthroline ring, with a dihedral angle between their least-squares planes of 8.86 (6)°. In the crystal, the molecules are linked by C—H⋯O interactions.

Data collection: CrystalClear (Pflugrath, 1999); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012)   The molecules are essentially planar, although the plane of the oxadiazolic five membered thionyl groups are slightly rotated from the phenanthrolene plane (the two least-squares planes form an angle of 8.86 (5)°). The molecules are arranged in planar sheets, with each pair of thiol S atoms pointing at the two apical hydrogen atoms on the adjacent phenanthroline groups.

Experimental
1,10-Phenanthroline-2,9-Di-S-methylhydrazinecarbodithioate (0.100 g, 0.21 mmol) was dissolved in THF (30 mL) with heat until a clear solution was formed. Then a solution of ZnCl 2 (0.015 g, 0.11 mmol) in THF (5 mL) was added dropwise to the carbodithioate solution. The resulting mixture was refluxed for 2-4 hrs. After completion of the reaction, as indicated by TLC, the reaction mixture was allowed to cool to room temperature. The solvent was evaporated under

Refinement
One large residual peak near the DMSO solvent molecule appears to indicate an alternate position of the S atom (an inversion of the DMSO pyramid). The disorder of the S atom was refined to an occupancy of less than 5% for the minor position; the minor occupancy of the lighter atoms of the solvent molecule were not included in the model.
Non-hydrogen atoms were refined with anisotropic thermal parameters, and hydrogen atoms were included in calculated positions (riding model) with U iso set to 1.2 times the U eq of the parent atom. Refinement on F2 by full-matrix least-squares resulted in R1 = 0.0727 and wR2 = 0.1729 for 2742 reflections with I > 2σ (I).

Computing details
Data collection: CrystalClear (Pflugrath, 1999); cell refinement: CrystalClear (Pflugrath, 1999); data reduction: CrystalClear (Pflugrath, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to supplementary materials sup-2 Acta Cryst. (2014). E70, o321-o322 refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012) and publCIF (Westrip, 2010).   Special details 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ. (