[5,10,15,20-Tetrakis(pentafluorophenyl)porphyrinato]zinc(II) benzene disolvate

The porphyrinato core of the title zinc porphyrinato complex is approximately planar, and the cation has no other ligating atoms than the four porphyrinato N atoms. The molecular complex exhibits point group symmetry with the central ZnII atom located on an inversion centre.


Structure description
Metalloporphyrin derivatives have been investigated extensively, not only as heme models but also as functional building blocks of molecular materials and devices. Zinc porphyrins have been employed as photosensitizers (Liu et al., 2006) and chemical sensors (Wu et al., 2016) because of their good photoelectronic and chemical stabilities. In 1995, Gray and co-workers published the first zinc porphyrin crystal structure, (5,10,15,20-tetrakis(pentafluorophenyl)porphyrinato)zinc(II) n-hexane solvate, which crystallizes in the space group P2 1 /c and shows a planar conformation of the porphyrin ligand (Birnbaum et al., 1995). In this work, a new zinc pentafluorophenyl-porphyrin crystal structure, [Zn(TFPP)]Á2C 6 H 6 (TFPP is the tetrakis(pentafluorphenyl)porphyrinato ligand), is reported.
The molecular entities of the title compound are shown in Fig. 1. The structural features of the current complex are similar to those of the previously reported [Zn(TFPP)] n-hexane solvate (Birnbaum et al., 1995). As can be seen, the porphyrinato core is approximately planar (r.m.s. deviation = 0.03 Å ). Two benzene solvent molecules are found besides the [Zn(TFPP)] units. One of them is found to be disordered (CS1-data reports CS6) over two positions.stacking interactions are observed between the disordered benzene molecules and [Zn(TFPP)] moieties, as illustrated in Fig. 2. The distance between the centroid of the benzene ring (X cent ) and the porphyrinato plane is 3.098 Å , which is consistent with the reported values for related complexes (about 3.33-3.45 Å ; Uno et al., 2003).
Intermolecular non-bonding interactions are also found for the title compound. As given in Fig. 3 and Table 1, the distance between CB3 and F4, HB3 and F4 are 3.276 and 2.36 Å , respectively, being consistent with C-HÁ Á ÁF hydrogen bonds (3.455 and 2.53 Å , respectively; Thamotharan et al., 2003). The packing pattern of the title compound is shown in Fig. 4.

Synthesis and crystallization
General Information. All operations were accomplished by standard Schlenk techniques unless otherwise specified. Benzene, which was used for crystallization of the final products, was washed with concentrated sulfuric acid and then with sodium bicarbonate solution at least three times, dried with anhydrous magnesium sulfate and distilled with calcium hydride, sodium and diphenylketone, sequentially under argon atmosphere. The precursor compound H 2 (TFPP) was synthesized by the method reported by Lindsey et al. (1987).
Synthesis of [5,10,15,20-tetrakis(pentafluorophenyl)porphyrinato]zinc(II) benzene disolvate H 2 (TFPP) (500 mg, 0.51 mmol) and Zn(Ac) 2 Á2H 2 O (2.25 g, 10.26 mmol) were dissolved in 250 ml of CH 3 OH and 250 ml of CHCl 3 . After the solution had been transferred to a conical flask (1000 ml), it was refluxed under stirring for 4 h under argon. The raw products were washed with deionized water to remove the remaining zinc salts. The organic phases were dried and purified by column chromatography using silica and eluting the product with hexane/dichloromethane (2:1). Redpink [Zn(TFPP)] powder (yield 489 mg, 0.47 mmol, 91.8%), was obtained after solvent evaporation. Red single crystals of the title compound were grown by slow solvent evaporation of Schematic illustration ofstacking in the crystal structure of the title compound showing the distance between the centroid of benzene ring (Xcent) and the porphyrinato plane.  Symmetry code: (i) Àx þ 1 2 ; y À 1 2 ; Àz þ 1 2 .

Figure 1
ORTEP diagram of the molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. Only one orientation of the disordered solvent benzene molecule (CS1-CS6) is shown. H atoms are omitted for clarity.

Figure 4
A view of the packing pattern of the title compound with the unit cell indicated by orange lines. H atoms are omitted for clarity. a solution of the title compound in freshly distilled benzene at room temperature.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. A solvent benzene molecule is observed to be disordered over two positions of equal occupancy (CS1-CS6). These atoms and corresponding bonds were restrained by ISOR and RIGU commands, respectively.  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.38 e Å −3 Δρ min = −0.38 e Å −3 Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. Refinement. All of hydrogen atoms were placed in calculated positions (C-H = 0.95 Å for aryl hydrogen atoms) and were refined using a riding model with fixed isotropic displacement parameters of U iso (H) = 1.2U eq (C).