meso-α,α-5,15-Bis(o-nicotinamidophenyl)-10,20-diphenylporphyrin n-hexane monosolvate

In the title porphyrin solvate, the macrocycle shows a characteristic saddle-shaped distortion.

The structure of the title solvated porphyrin, C 56 H 38 N 8 O 2 •C 6 H 14 , is reported.Two porphyrin molecules, one ordered and one disordered n-hexane solvate molecules are present in its asymmetric unit.The porphyrin macrocycle shows a characteristic saddle-shaped distortion, and the maximum deviation from the mean plane for non-hydrogen atoms is 0.48 A ˚. N-H� � �N, N-H� � �O, and C-H� � �O hydrogen bonds, as well as �-� interactions, are observed in the crystal structure.

Structure description
The characterization of a large class of porphyrins and their metallated derivatives has generated considerable interest because of their applications in catalysis and the preparation of new functional materials.For example, they are useful in photodynamic therapy (Ethirajan et al., 2011;Bonnett, 1995;Peters et al., 2018), as catalysts in nature (Shultz et al., 2009;Li & Zamble, 2009), for important materials for dye-sensitized solar cells (Urbani et al., 2014), or as responsive contrast agents in functional magnetic resonance imaging (Venkataramani et al., 2011;Dommaschk et al., 2015).Additionally, they are present throughout the biosphere and perform a wide range of bioinorganic functions (Averill, 1996).The presence or absence of a metal ion at the porphyrin core can greatly affect its physical properties, such as catalytic activity and crystal packing.Therefore, the design and synthesis of structurally diverse molecules are essential.Herein, we report the structural properties of a new solvated porphyrin compound, C 56 H 38 N 8 O 2 •C 6 H 14 .
The asymmetric unit of the title solvate contains two porphyrin molecules, one disordered n-hexane solvate molecule and one ordered n-hexane solvate molecule.Figs. 1 and 2 graphically represent the molecular structure of the title porphyrin; n-hexane (C 6 H 14 ) is the lattice solvent, which has been omitted in Fig. 1.As can be seen, the two porphyrin molecules are alternately embedded together in the asymmetric unit.More quantitative numerical information is given in Fig. 3, which contains the detailed displacement of each porphyrin core atom (in units of 0.01 A ˚) from the 24-atom mean plane.The porphyrin core shows a characteristic saddle-shaped distortion and the maximum deviation from the 24-atom mean plane of the non-hydrogen atoms is 0.48 A ˚, for atom C12B.
In the crystal, N-H� � �N, N-H� � �O and C-H� � �O hydrogen-bonding, as well as �-� interactions are found between the two porphyrin molecules, as illustrated in Fig. 4 and detailed in Table 1.As can be seen in Fig. 4, the interplanar distance between the relevant centroids of the rings in the �-� stacking interactions is 3.758 (2) A ˚, which is consistent with literature data (range 3.3-3.8A ˚; Janiak, 2000;Khavasi & Fard, 2010).The distance between N10 and N13 is 3.015 (3) A ˚and the N-H� � �N angle is 163 � in the N-H� � �N     hydrogen-bonding interactions (Fig. 4, Table 1).Similar hydrogen-bonding interactions are also found between N12 and N15, with a distance of 2.963 (3) A ˚and an N-H� � �N angle of 156 � .All these structural parameters are consistent with literature data where N-H� � �N bonds fall in the range 2.6-3.2A ˚, with angles of 120.5-179.7 � (Prasad & Govil, 1980;Aldilla et al., 2017).Moreover, N-H� � �O and C-H� � �O hydrogen bonds are also found between adjacent porphyrin molecules (Fig. 4, Table 1).Furthermore, weak intramolecular N-H� � �N hydrogen-bonding interactions are found in each porphyrin molecule (Fig. 4, Table 1).The molecular packing of the title compound is shown in Fig. 5.
Under an argon atmosphere, compound ��-TPP-amino (300 mg, 0.46 mmol) was dissolved in anhydrous DCM (25 ml).Nicotinoyl chloride hydrochloride (202.5 mg, 1.15 mmol) was dissolved in anhydrous pyridine (20 ml) under an Ar atmosphere.Then, the ��-TPP-amino solution was slowly added into the pyridine solution and the mixture was refluxed for 30 minutes at 368 K under Ar.After the reaction mixture had cooled to room temperature, silica gel was loaded on the top of silica gel column.The crude product was purified by column chromatography (chloroform/hexane from 1:3 to 1:0) on silica and finally recrystallized from DCM/MeOH.The solvent was removed under reduced pressure to afford the pure compound ��-ortho-amide as a purple crystalline solid (216 mg, 55% yield).
To grow single crystals, ��-ortho-amide (15 mg) was dissolved in 5 ml of tetrahydrofuran and cannula-transferred into 8 mm glass tubes, then carefully layered with n-hexanes before sealing the tubes.X-ray quality crystals were obtained after several weeks.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2.The disordered hexane molecule, C73-C78/C73-C78A, occupies two sites with refined occupancies of 0.661 (6) and 0.339 (6).All C atoms in this disordered molecule were restrained to have similar displacement parameters with standard deviation of 0.04 A ˚2, and C74 was restrained to approximate an isotropic behaviour (SIMU and ISOR commands;Sheldrick, 2015b).Finally, C-C bond lengths in this molecule were restrained to 1.50 (2) A ˚ (DFIX command;Sheldrick, 2015b

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Figure 5 A view of the molecular packing in the crystal structure of the title compound, as seen in a projection along [110].H atoms and solvent molecules have been omitted for clarity.

Figure 2
Figure 2Edge view of the porphyrin complex of the title compound with displacement ellipsoids drawn at the 50% probability level.A disordered nhexane solvate molecule, an ordered n-hexane solvate molecule and two porphyrin molecules are shown.Hydrogen atoms are omitted for clarity.

Figure 3 A
Figure 3 A formal diagram of the porphyrin core of the title compound.Averaged values of the chemically unique bond lengths (A ˚) and angles ( � ) are shown.The numbers in parentheses are the e.s.d.'s calculated on the assumption that the averaged values were all drawn from the same population.The perpendicular displacements (in units of 0.01 A ˚) of the porphyrin core atoms from the 24-atom mean plane are also displayed.Positive numbers indicate a displacement toward the pyridine groups.

Figure 1
Figure 1Top view of the porphyrin complex of the title compound with ellipsoids drawn at the 50% probability level.Hydrogen atoms, a disordered nhexane solvate molecule, an ordered n-hexane solvate molecule and one porphyrin molecule are omitted for clarity.

Figure 4 N
Figure 4 N-H� � �N, N-H� � �O and C-H� � �O hydrogen-bonding interactions and relevant intermolecular �-� interactions in the crystal structure of the title compound (dashed lines).

Table 2
Experimental details.