Dichlorido(5,10,15,20-tetraphenylporphyrinato-κ4 N)antimony(V) hexachloridoantimonate(V)

The asymmetric unit of the title compound, [Sb(C44H28N4)Cl2][SbCl6], consists of one half of an antimony(V) tetraphenylporphyrin complex cation and one half of an hexachloridoantimonate(V) anion. In the complex cation, the SbV atom lies on an inversion center and is octahedrally coordinated by four N atoms from a macrocyclic tetraphenylporphyrinate ligand and two chloride ions. The complex cation has approximately a planar core with a maximum deviation of 0.018 (5) Å from the porphyrin mean plane. The average Sb—N distance is 2.062 (11) Å, while the Sb—Cl distance is 2.355 (1) Å. The SbV atom of the anion is also located on an inversion center. The [SbCl6]− octahedron exhibits rhombic distortion characterized by the Sb—Cl bond lengths [2.311 (3), 2.374 (2) and 2.393 (4) Å]. In the crystal, the cations and anions are linked C—H⋯ Cl hydrogen bonds, forming a layer parallel to (211).

The asymmetric unit of the title compound,  )Cl 2 ][SbCl 6 ], consists of one half of an antimony(V) tetraphenylporphyrin complex cation and one half of an hexachloridoantimonate(V) anion. In the complex cation, the Sb V atom lies on an inversion center and is octahedrally coordinated by four N atoms from a macrocyclic tetraphenylporphyrinate ligand and two chloride ions. The complex cation has approximately a planar core with a maximum deviation of 0.018 (5) Å from the porphyrin mean plane. The average Sb-N distance is 2.062 (11) Å , while the Sb-Cl distance is 2.355 (1) Å . The Sb V atom of the anion is also located on an inversion center. The [SbCl 6 ] À octahedron exhibits rhombic distortion characterized by the Sb-Cl bond lengths [2.311 (3), 2.374 (2) and 2.393 (4) Å ]. In the crystal, the cations and anions are linked C-HÁ Á Á Cl hydrogen bonds, forming a layer parallel to (211).

Experimental
The title compound [Sb(tpp)Cl 2 ][SbCl 6 ] synthesis was performed under argon atmosphere. SbCl 5 (3-4 cm 3 ) was added to a solution of tetraphenylporphyrin (H 2 tpp) (500 mg, 0.814 mmol) in pyridine (25 cm 3 ) and the resulting mixture was refluxed for 1 h. After removing pyridine and excess antimony pentachloride by rotary evaporation, the purple solid obtained was dissolved in dichloromethane and chromatographed on silica gel 60 (100 g, neutral, activity I). The reaction mixture was firstly eluted with CH 2 C1 2 to eliminate any free H 2 tpp present and then the title compound was eluted as a purple band using CH 2 C1 2 -methanol (2%). Single red crystals of the title complex, suitable for X-ray diffraction, have been obtained by diffusion of hexanes in dichloromethane solution.

Refinement
All H atoms were refined using a riding model with C-H = 0.93 Å and U iso (H) = 1.2U eq (C).  The molecular structure of the title compound with displacement ellipsoids drawn at 30% probability level. Hydrogen atoms have been omitted for clarity.

Figure 2
A crystal packing diagram of the title compound viewed along the b axis.

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