Crystal and Molecular Structure of 4-Benzoyl-1 , 5-diphenyl-1 H-pyrazole-3-carbonitrile

The crystal structure of potential active 4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carbonitrile (C23H15N3O) (I) has been determined from single crystal X-ray diffraction data. Also IR, Uv-vis and NMR spectral data were determined. The title compound crystallizes in the monoclinic space group P 21/c, with a = 9.3167(2), b = 20.6677(3), c = 10.6143(3) Å, β = 112.665(3) ̊, V = 1886.00(8) Å, Dcalc = 1.23g cm, Z = 4. In the structure, intermolecular H-bonds lead to the formation of a centrosymmetric dimmer of the molecule. Furthermore, the compound has a wide transmission window (300 to 1100 nm) with a transparency of nearly 100% and the UV cut-off wavelength occurs at 242 nm.


Synthesis of the Title Compound
The title compound was prepared by the reaction of 4benzoyl-1,5-diphenyl-1H-pyrazole-3-carboxylic acid amide with DMF and SOCl 2 (Figure 1).A cold solution of the acid amide (0.37 g, 1.0 mmol) in a mixture of DMF (0.7 mL) and SOCl 2 (0.15 mL) was stirred at 0˚C -5˚C for 2 h similarly given in [5], and the solution was left stirring overnight.Then the mixture was poured over crushed ice and the precipitate formed was filtered off, washed with water and recrystallized from methanol and dried on P 2 O 5 M.p. 167˚C, yield 70% (0.245 g).The authenticity of the compound has been established by microanalyses, UV, IR, 1 H and 13 C NMR spectra.

Materials and Physical Measurements
The melting point was determined on an Electrother-malModel 9200 apparatus and is uncorrected.The IR ab  sorption spectrum (Figure 6) was obtained in the region of 400 -4000 cm -1 with a resolution of 4 cm -1 as KBr pellet using a Jasco Plus Model 460 FT IR spectrometer.
Microanalysis was performed with a Carlo Erba Elemental Analyzer, model 1108.UV-vis spectrum was recorded in the range of 200 nm to 1100 nm using a Lambda 35 Perkin-Elmer spectrophotometer for the optical transmission studies (Figure 5).The 1 H and 13 C NMR (Figure 7) spectra were determined on a Bruker Avance 400 model spectrometer at 400 MHz and 100 MHz, respectively.All materials were purchased from commercial companies (Merck, Sigma, Aldrich and Fluka) and used directly without further purification.Solvents were dried by refluxing with the appropriate drying agents and distilled before use.

X-Ray Crystallography
For the crystal structure determination, the single-crystal of the compound C 23 H 15 N 3 O was used for data collection on a four-circle Rigaku R-AXIS RAPID-S diffractometer (equipped with a two-dimensional area IP detector).The graphite-mon-chromatized Mo K α radiation (λ = 0.71073 Å) and oscillation scans technique with Δω = 5˚ for one image were used for data collection.The lattice parameters were determined by the least-squares methods on the basis of all reflections with F 2 > 2σ(F 2 ).Integration of the intensities, correction for Lorentz and polarization effects and cell refinement was performed using CrystalClear software [33].The structures were solved by direct methods using SHELXS-97 [34] and refined by a full-matrix least-squares procedure using the program SHELXL-97 [34] 3).The title compound also contains intermolecular C-H… interaction.Atom C (22) in the molecule at (x, y, z) acts as hydrogen-bond donor to the C7/C12 phenyl ring in the molecule at (-1 + x, y, -1 + z), so forming a chain running parallel to the [100] direction.Elemental analysis of compound for carbon, hydrogen, and nitrogen are in good agreement with theoretical values.The theoretical and observed element percentages respectively are: %C: 79.07 and 78.94, %H: 4.33 and 4.45, %N: 12.03 and 12.18.

Results and Discussion
Optical transmission spectrum of the compound is shown in Figure 5.The range of optical transmittance and the transparency cut-off are important parameters for a single crystal used in optical applications.It has a wide transmission window (300 to 1100 nm) with a transparency of nearly 100% and the UV cut-off wavelength occurs at 242 nm.The wide transmission range in the entire visible region is a useful property for opto-electronic applications.Hence, the title compound has become a  good candidate for optoelectronic applications.ompound The FT IR spectrum (Figure 6) of the title c show sharp absorption bands occurred in the range 3095-3000 cm -1 due to the aromatic (C-H) stretching vibrations.The sharp and middle-intensity IR absorption band of the nitrile (-C=N) group founds at 2246 cm -1 .Weak combination or overtone bands appear in the 2000-1670 cm -1 region.The strong characteristic absorption band at 1652 cm -1 indicate the C=O (benzoyl) group of the compound [40].
The structure of the title compound was further characterized by NMR absorption.Important structural information about can be obtained from its NMR spectra.In the 13 C-NMR spectrum (Figure 7) of the CDCl 3 solution of the compound was observed = 188.24    -1 to represent the aromatic carbons and a singlet peak at 112.37 ppm represent the nitrile group [40].Therefore, final confirmation of the stru mpound was derived from its 1 H-NMR spectrum: =7.72 -7.09 ppm a set of signals for aromatic protons.
Consequently, the liminary compound due to the fact that original pyrazole-3-carboxylic acid derivative includes nitrile group in its structure.It is air-stable in the solid state, crystallized from methyl alcohol and insoluble in water.Additionally, it has good solubility in common organic solvents, such as CH 2 Cl 2 , THF, DMF, DMSO, CHCl 3 , acetone and toluene.The authenticity of the compound has been established by UV, IR, NMR, XRD and elemental analysis techniques.The title compound characterized can be essential in medicinal and biological applications.Some pyrazole derivatives, as known, have been used to treat some diseases [30][31][32].The title structure may be widespread biological significance.Further investigation on the mechanism, potential activity and the optimal reaction condition is currently in progress.

Figure 1 .
Figure 1.Chemical structure and synthesis pathway of the title compound.
Title compound crystallizes in the monoclinic centrosymmetric space group P 21/c (no: 14) with Z = 4.The structure of the compound consists of cyano, benzoyl and two phenyl fragments that connected to the pyrazole ring.Due to the strong steric hindrance, phenyl moieties are considerably twisted according to the pyrazole plane.Dihedral angles between the phenyl planes 1-2, 1-3, 2-3 [C1/C6 (1), C7/C12 (2), C18/C23 (3)] are 39.18(8)˚, 59.57(7)˚, 88.98(7)˚, respectively.The N-C distances 1.330 and 1.362(3) Å deviate significantly from the mean value of N-C distances in pyrazole rings 1.357(12) Å[35][36][37].It has been reported[38] that the N-N bond length in the pyrazoline ring varies over a wide range, from 1.234(8) to 1.385(4) Å, where the length depends on the substituents bonded to the N atoms.Accordingly, the length of the adjacent C=N bond ranges from 1.288(4) to 1.461(8) Å.These differences are caused by a varying degree of conjugation in the -electron portion of the pyrazoline ring, which is sensitive to the nature of the substituent(s) bonded to the atoms of the  system.The N2-N3 bond length of 1.358(3) Å found in the title compound further extends this range, approximating the length of a pure single bond 1.41 Å [39].In the structure, benzoyl groups are joined by two C-H•••O [C(12)•••O(1) a = 3.157(3) Å, C(12)-H•••O(1) a = 119˚, symmetry code (a); 2 -x, -y, 1 -z] H bonds, which lead to the formation of a centrosymmetric dimer of the molecule in the crystal unit cell (Figure

Figure 2 .
Figure 2. Molecular structure of the compound showing the atomic numbering system.Displacement ellipsoids are drawn at the 30% probability level.

Figure 3 .
Figure 3. Part of the crystal structure of the molecule, showing the formation of a centrosymmetric dimer.Atoms marked with an (a) are at the symmetry position (2x, -y, 1z).

Figure 5 .
Figure 5. Optical transmission spectrum of the title compound.

Figure 6 . 6 Figure 7 .
Figure 6.FT-IR spectrum for the title compound in KBr pellet.

Table 2 .
Selected bond distances and bond angles are listed in