Bis(phenanthridinium) hexachloridoplatinate(IV) dimethyl sulfoxide disolvate

The asymmetric unit of the title compound, (C13H10N)2[PtCl6]·2C2H6OS, contains one independent protonated phenanthridinium cation, half of a centrosymmetric [PtCl6]2−anion and one dimethyl sulfoxide solvent molecule. Intramolecular N—H⋯O and intermolecular C—H⋯Cl hydrogen-bonding interactions seem to be effective in the stabilization of the structure.

The asymmetric unit of the title compound, (C 13 H 10 N) 2 -[PtCl 6 ]Á2C 2 H 6 OS, contains one independent protonated phenanthridinium cation, half of a centrosymmetric [PtCl 6 ] 2À anion and one dimethyl sulfoxide solvent molecule. Intramolecular N-HÁ Á ÁO and intermolecular C-HÁ Á ÁCl hydrogen-bonding interactions seem to be effective in the stabilization of the structure.
The asymmetric unit of the title compound (I), (Fig. 1) contains one independent protonated phenanthridinium cation and one half PtCl 2-6 anion, and one dimethyl sulfoxide solvate. The Pt ion has an octahedral coordination (Table 1). In cation, the bond lengths and angles are normal. In PtCl 2-6 anion, the Pt-Cl bond lengths and Cl-Pt-Cl bond angles are also within normal ranges, as in (III) to (XV).
The intramolecular N-H···O and intermolecular C-H···Cl hydrogen bonding interactions (Table 1) seem to be effective in the stabilization of the structure (Fig. 2).

S2. Experimental
For the preparation of the title compound, (I), a solution of phenanthridine (0.27 g,1.48 mmol) in ethanol (10 ml) was added to a solution of H 2 PtCl 6 .6H 2 O, (0.38 g, 0.74 mmol) in ethanol (10 ml) at room temperature. The suitable crystals for X-ray diffraction experiment were obtained by ethanol diffusion in a solution of orange precipitated in DMSO after one week [yield; 0.51 g, 74.7%, m.p. < 573 K].

S3. Refinement
The C-bound H-atoms were placed in calculated positions with C-H = 0.93 Å and C-H 0.96 Å, and were included in the refinement in the riding model approximation, with U iso (H) = 1.2U eq (ring C) and U iso (H) = 1.5U eq (methyl C). The Nbound H-atom was found from a difference Fourier map and refined freely. In the final Fourier map, the highest and deepest peaks were located 1.13 and 0.47 Å from atom S1, respectively.

Bis(phenanthridinium) hexachloridoplatinate(IV) dimethyl sulfoxide disolvate
Crystal data (C 13  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 2.20 e Å −3 Δρ min = −1.01 e Å −3 Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses 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 observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs 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.