Papers by MOHAMMAD IFZAN ARSHAD
The crystal structure of m-methoxy-N-(m-anisoyl)-N-phenylbenzohydrazide has been determined by me... more The crystal structure of m-methoxy-N-(m-anisoyl)-N-phenylbenzohydrazide has been determined by means of single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group P 21/c with unit cell parameters: a = 8.7338(1), b = 24.5602(3), c = 9.6929(1) Å, β = 113.186(2) • , V = 1911.23(4) Å 3 , Z = 4. The dihedral angles between the mean plane of the central benzene ring and two terminal aromatic rings are 72.44(4) • and 89.90(4) • , respectively. The two methoxyphenyl rings are orthogonal with a dihedral angle of 89.74(4) •. The crystal packing is stabilized by a combination of N–H. .. O intermolecular hydrogen bonding and weak intermolecular C–H. .. O interactions. The X-ray structure was compared with the optimized counterpart calculated by the B3LYP/6-311G basis set and the results showed that the optimized geometry can reproduce the crystal structure parameters well.
Rapid increase in bacterial resistance has become a major public concern by escalating alongside ... more Rapid increase in bacterial resistance has become a major public concern by escalating alongside a lack of development of new anti-infective drugs. Novel remedies in the battle against multidrug-resistant bacterial strains are urgently needed. So, in this context, the present work is towards the investigation of antimicrobial efficacy of some novel keto ester derivatives, which are prepared by the condensation of substituted benzoic acids with various substituted phenacyl bromides in dimethylformamide at room temperature using triethylamine as a catalyst. The structural build-up of the target compounds was accomplished by spectroscopic techniques including FTIR, 1H and 13C NMR spectroscopy and mass spectrometry. The purity of the synthesized compounds was ascertained by elemental analysis. The molecular structures of compounds (4b) and (4l) were established by X-ray crystallographic analysis. The prepared analogues were evaluated for their antimicrobial activity against Gram-positive (Staphylococcus aureus, Micrococcus leuteus) and Gramnegative (Pseudomonas picketti, Salmonella setuball) bacteria and two fungal pathogenic strains (Aspergillus niger, Aspergillus flavus), respectively. Among the screened derivatives, several compounds were found to possess significant activity but (4b) and (4l) turned out to be lead molecules with remarkable antimicrobial efficacy. The structure-activity relationship analysis of this study also revealed that structural modifications on the basic skeleton affected the antimicrobial activity of the synthesized compounds.
The title compound 1-benzyl-5-((4-methoxyphenyl)ethynyl)-4-phenyl-1H-1,2,3-triazole (C24H19N3O) w... more The title compound 1-benzyl-5-((4-methoxyphenyl)ethynyl)-4-phenyl-1H-1,2,3-triazole (C24H19N3O) was designed and synthesized using one-pot strategy and structural characterization was done by single-crystal X-ray diffraction, NMR, IR and MS. This compound was crystallized out from an ethanolic solution in triclinic system, space group P1 with a =
9.9038(9), b = 10.2928(9), c = 18.8715(19) Å, α = 103.541(6), β = 90.507(7), γ = 97.157(7)°, V = 1854.2(3) Å3, Z = 4, crystal size (mm) = 0.25 × 0.1 × 0.1 and Rint = 0.068. Its asymmetric unit
contains two independent molecules. The crystal structure of the title compound is stabilized by intramolecular interactions of types C–H···N and C–H···O. Additionally, X-ray analysis reveals
obvious C–H···π, π-π stacking interactions between two adjacent aromatic ring planes.
The 2-(phenyl-hydrazono)-succinic acid dimethyl ester compound was synthesized by reacting phenyl... more The 2-(phenyl-hydrazono)-succinic acid dimethyl ester compound was synthesized by reacting phenylhydrazine with dimethylacetylene dicarboxylate at room temperature and characterized by elemental analysis, infrared, Raman, 1H and 13C NMR spectroscopies and mass spectrometry. Its solid state structure was determined by X-ray diffraction methods. The X-ray structure determination corroborates that the molecule is present in the crystal as the hydrazone tautomer, probably favored by a strong intramolecular N–H···O=C hydrogen bond occurring between the carbonyl (–C=O) and the hydrazone –C=N–NH– groups. A substantial fragment of the molecular
skeleton is planar due to an extended -bonding delocalization. The topological analysis of the electron densities (Atom in Molecule, AIM) allows to characterize intramolecular N–H···O
interaction, that can be classified as a resonant assisted hydrogen bond (RAHB). Moreover, the Natural Bond Orbital population analysis confirms that a strong hyperconjugative lpO1→ *(N2–H) remote interaction between the C2=O1 and N2–H groups takes place. Periodic system electron density and topological analysis have been applied to characterize the intermolecular interactions in the crystal. Weak intermolecular interactions determine the packing and the prevalence of non directional dispersive contributions are inferred on topological grounds. The IR spectrum of the crystalline compound was investigated by means of density functional theory calculations carried out with periodic boundary conditions on the crystal, showing excellent agreement between theory and the experiments. The vibrational assignment is complemented
with the analysis of the Raman spectrum.
A novel hydrazide compound (C16H24N2O2) is synthesized in a single step by the reaction of pivalo... more A novel hydrazide compound (C16H24N2O2) is synthesized in a single step by the reaction of pivaloyl chloride with phenylhydrazine in a 2:1 molar ratio in dry DCM. The molecular structure is determined by the single crystal X-ray analysis. The compound crystallized in the monoclinic system, space group P21/c with a = 15.4638(17) Å, b = 9.9481(11) Å, c = 10.5276(12) Å, β = 90.194(3)°, Z = 4, V = 1619.5(3) Å3.
Two new 1,4-disubstituted 1,2,3-triazoles-4-carboxylates were synthesized via click reaction. Com... more Two new 1,4-disubstituted 1,2,3-triazoles-4-carboxylates were synthesized via click reaction. Compound 1a was synthesized by the interaction of 6-nitro-tetrazolo[1.5-a]-pyridine with ethyl propynoate at room temperature in the presence of Cu(OAc)2 as a catalyst and THF as solvent. Compound 1b was also synthesized by the same manner except that tert-butyl propionate, instead of ethyl propynoate, was used. The compounds were characterized by IR, 1H-NMR, 13C-NMR and single-crystal X-ray diffraction analysis. Compound 1a (C10H9N5O4) crystallizes in the triclinic system, space group P1 with a = 5.0894(9), b = 8.9834(13), c = 13.089(2) Å, a = 83.041(7), b = 80.256(7), g = 87.296(8)°, V = 585.24(16) Å3, Z = 2, Mr = 263.22, crystal size (mm) = 0.37 × 0.20 × 0.18, (I > 2σ(I)) = 8557, 2493, 1229, Rint = 0.057. Compound 1b (C12H13N5O4) crystallizes in the monoclinic system, space group P21/c with a = 6.8854(5), b = 21.783(2), c = 9.3986(8) Å, b = 93.239(4)°, V = 1407.4(2) Å3, Z = 4, Mr = 291.27, crystal size (mm) = 0.38 × 0.22 × 0.20, (I > 2σ(I)) = 11842, 3172, 1866, Rint = 0.047. Antimicrobial assay results showed that the title compounds display excellent activities to different bacterial and fungal strains.
One-pot three component reaction was used to synthesize 1,4,5-trisubstituted 1,2,3-triazole (A) f... more One-pot three component reaction was used to synthesize 1,4,5-trisubstituted 1,2,3-triazole (A) from the corresponding acid chloride, benzyl azide and 1-copper(I) phenylethyne. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the orthorhombic space group Pbca, a = 14.9815(14), b = 9.6496(10), c = 25.528(2) Å, Z = 8. Furthermore, crystal packing demonstrated a molecular wall-like structure based on supramolecular chains of A, stabilized by CH···O, CH···Br, N···C and CH···π interactions. Molecular geometry in the ground state has been determined by density functional theory (DFT) by B3LYP/6-311G* basis set and compared with the experimental data. The computed vibrational frequencies are compared with the experimental FT-IR data and frontier molecular orbital analyses were performed at the same level of theory. Theoretical parameters are in good agreement with the corresponding X-ray diffraction values.
A novel 1,4,5-trisubstituted 1,2,3-triazole (C18H21N3O3) was synthesized by a one-pot three compo... more A novel 1,4,5-trisubstituted 1,2,3-triazole (C18H21N3O3) was synthesized by a one-pot three component reaction of 1-azidocyclohexane, 1-copper(I) phenylethyne and ethoxalyl
chloride at room temperature. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the monoclinic system, space group P21/n with a = 12.8167(9), b = 8.0966(6), c = 16.7079(9) Å, β = 98.716(2)º, Z = 4 and V = 1713.8(2). In the crystal, the molecules are related by inversion and paired into dimers via C–H···O and C–O···C interactions involving (oxo) acetate groups. Furthermore, X-ray analysis results are compared with the optimized structure computed by using B3LYP method with 6-311G basis set. The calculated results showed that optimized geometry can well reproduce the crystal structure parameters. The bioassay results indicate that the compound has good antibacterial and antifungal activities.
A new polymorph (II) of 2,5-dibenzylidenecyclopentanone (DBCP) has been obtained by slow evaporat... more A new polymorph (II) of 2,5-dibenzylidenecyclopentanone (DBCP) has been obtained by slow evaporation of ethanol solvent at room temperature. Interestingly, two conformational isomers of the title compound with slight difference in their bond lengths, torsion angles and dihedral angles were found within the same crystal lattice of polymorph (II). The crystal structure of polymorph (II) showed monoclinic P2 1 space group with a = 6.0983 (2) Å, b = 14.9200 (7) Å, c = 15.0740 (6) Å, V= 1368.69 Å 3 , Z = 2 as compared to orthorhombic C222 1 space group with a = 11.803 (2) Å, b = 5.698 (4) Å, c = 20.872 (2) Å, V= 1403.6 Å 3 , Z = 4 for previously reported polymorph (I) crystallized in CHC1 3 /MeOH solvent. The concomitant origin of polymorphism and conformational isomerism was credited to C-H … O, π-π and C-H … π interactions resulting in intriguing supramolecular sheet-like multilayered molecular packing of polymorph (II). The results of the complementary electronic structure calculations, performed by DFT/B3LYP method using 6-31G* basis set were found in good agreement with the experimental results.
A new hydrazide derivative N -(2,4-dinitrophenyl)-2-fluorobenzohydrazide was synthesized and char... more A new hydrazide derivative N -(2,4-dinitrophenyl)-2-fluorobenzohydrazide was synthesized and characterized by NMR and IR spectroscopy. The molecular structure was also studied by X-ray diffraction, and the results of the optimized molecular structure are presented and compared with density functional methods with 631-G basis set. The calculated results show that the optimized geometry can well reproduce the crystal structural parameters, for example, bond lengths and angles show good agreement with the experimental data.
Acta Crystallographica Section E: …, Jan 1, 2012
In the title compound, C13H10N4O5, the aromatic ring planes are close to perpendicular [dihedral ... more In the title compound, C13H10N4O5, the aromatic ring planes are close to perpendicular [dihedral angle = 75.94 (5)°] and the C—N—N—C torsion angle is 88.7 (2)°. Both nitro groups lie close to their attached ring plane, with C—C—N—O torsion angles of 3.1 (2) and 5.3 (2)°. This allows for the formation of an intramolecular N—HO hydrogen bond, which closes an S(6) ring. In the crystal, N—HO hydrogen bonds link the molecules into zigzag chains extending along [100].
Crystals, Jan 1, 2012
The title compound, Methyl 5-Hydroxy-1-Phenyl-1H-Pyrazole-3-Carboxylate (C 11 H 10 N 2 O 3 ), was... more The title compound, Methyl 5-Hydroxy-1-Phenyl-1H-Pyrazole-3-Carboxylate (C 11 H 10 N 2 O 3 ), was prepared by a one-pot, two-component reaction of an equimolar mixture of phenyl hydrazine and dimethyl acetylene dicarboxylate (DMAD) at reflux temperature for 2 h in a mixture of toluene and dichloromethane as solvent. C 11 H 10 N 2 O 3 was crystallized from an ethanol solution in monoclinic space group P2 1 /c with unit cell dimensions a = 9.5408(16), b = 9.5827(16), c = 11.580(2) Å, β = 105.838(3)°, V = 1018.5(3) Å 3 , Z = 4.
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Papers by MOHAMMAD IFZAN ARSHAD
9.9038(9), b = 10.2928(9), c = 18.8715(19) Å, α = 103.541(6), β = 90.507(7), γ = 97.157(7)°, V = 1854.2(3) Å3, Z = 4, crystal size (mm) = 0.25 × 0.1 × 0.1 and Rint = 0.068. Its asymmetric unit
contains two independent molecules. The crystal structure of the title compound is stabilized by intramolecular interactions of types C–H···N and C–H···O. Additionally, X-ray analysis reveals
obvious C–H···π, π-π stacking interactions between two adjacent aromatic ring planes.
skeleton is planar due to an extended -bonding delocalization. The topological analysis of the electron densities (Atom in Molecule, AIM) allows to characterize intramolecular N–H···O
interaction, that can be classified as a resonant assisted hydrogen bond (RAHB). Moreover, the Natural Bond Orbital population analysis confirms that a strong hyperconjugative lpO1→ *(N2–H) remote interaction between the C2=O1 and N2–H groups takes place. Periodic system electron density and topological analysis have been applied to characterize the intermolecular interactions in the crystal. Weak intermolecular interactions determine the packing and the prevalence of non directional dispersive contributions are inferred on topological grounds. The IR spectrum of the crystalline compound was investigated by means of density functional theory calculations carried out with periodic boundary conditions on the crystal, showing excellent agreement between theory and the experiments. The vibrational assignment is complemented
with the analysis of the Raman spectrum.
chloride at room temperature. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the monoclinic system, space group P21/n with a = 12.8167(9), b = 8.0966(6), c = 16.7079(9) Å, β = 98.716(2)º, Z = 4 and V = 1713.8(2). In the crystal, the molecules are related by inversion and paired into dimers via C–H···O and C–O···C interactions involving (oxo) acetate groups. Furthermore, X-ray analysis results are compared with the optimized structure computed by using B3LYP method with 6-311G basis set. The calculated results showed that optimized geometry can well reproduce the crystal structure parameters. The bioassay results indicate that the compound has good antibacterial and antifungal activities.
9.9038(9), b = 10.2928(9), c = 18.8715(19) Å, α = 103.541(6), β = 90.507(7), γ = 97.157(7)°, V = 1854.2(3) Å3, Z = 4, crystal size (mm) = 0.25 × 0.1 × 0.1 and Rint = 0.068. Its asymmetric unit
contains two independent molecules. The crystal structure of the title compound is stabilized by intramolecular interactions of types C–H···N and C–H···O. Additionally, X-ray analysis reveals
obvious C–H···π, π-π stacking interactions between two adjacent aromatic ring planes.
skeleton is planar due to an extended -bonding delocalization. The topological analysis of the electron densities (Atom in Molecule, AIM) allows to characterize intramolecular N–H···O
interaction, that can be classified as a resonant assisted hydrogen bond (RAHB). Moreover, the Natural Bond Orbital population analysis confirms that a strong hyperconjugative lpO1→ *(N2–H) remote interaction between the C2=O1 and N2–H groups takes place. Periodic system electron density and topological analysis have been applied to characterize the intermolecular interactions in the crystal. Weak intermolecular interactions determine the packing and the prevalence of non directional dispersive contributions are inferred on topological grounds. The IR spectrum of the crystalline compound was investigated by means of density functional theory calculations carried out with periodic boundary conditions on the crystal, showing excellent agreement between theory and the experiments. The vibrational assignment is complemented
with the analysis of the Raman spectrum.
chloride at room temperature. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the monoclinic system, space group P21/n with a = 12.8167(9), b = 8.0966(6), c = 16.7079(9) Å, β = 98.716(2)º, Z = 4 and V = 1713.8(2). In the crystal, the molecules are related by inversion and paired into dimers via C–H···O and C–O···C interactions involving (oxo) acetate groups. Furthermore, X-ray analysis results are compared with the optimized structure computed by using B3LYP method with 6-311G basis set. The calculated results showed that optimized geometry can well reproduce the crystal structure parameters. The bioassay results indicate that the compound has good antibacterial and antifungal activities.