S. Sreenivasa

FT-IR, Laser-Raman spectra and quantum chemical calculations of methyl 4-(trifluoromethyl)-1H-pyrrole-3-carboxylate-A DFT approach

In this study the experimental and theoretical vibrational frequencies of a newly synthesized anti-tumor and anti-inflammatory agent namely, methyl 4-(trifluoromethyl)-1H-pyrrole-3-carboxylate have been investigated. The experimental FT-IR (4000-400cm(-1)) and Laser-Raman spectra (4000-100cm(-1)) of the molecule in solid phase have been recorded. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths, bond angles and torsion angles) have been calculated using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr and DFT/M06-2X: highly parameterized, empirical exchange correlation function) with 6-311++G(d,p) basis set by Gaussian 03 software, for the first time. The assignments of the vibrational frequencies have been done by potential energy distribution (PED) analysis using VEDA 4 software. The theoretical optimized geometric parameters and vibrational frequencies have been found to be in good agreement with the corresponding experimental data and results in the literature. In addition, the highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy and the other related molecular energy values of the compound have been investigated using the same theoretical calculations.

Vibrational frequency analysis, FT-IR and Laser-Raman spectra, DFT studies on ethyl (2E)-2-cyano-3-(4-methoxyphenyl)-acrylate

The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) of ethyl (2E)-2-cyano-3-(4-methoxyphenyl)-acrylate in solid phase have been recorded. Its theoretical vibrational frequencies, IR intensities, Raman activities and optimized geometric parameters (bond lengths and bond angles) have been calculated using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr and DFT/M06-2X: the highly parameterized empirical exchange correlation function) with 6-311++G(d, p) basis set by Gaussian 03 software, for the first time. The assignments of the vibrational frequencies have been done by potential energy distribution (PED) analysis using VEDA4 software. The optimized geometric parameters and vibrational frequencies have been seen to be in good agreement with the corresponding experimental data and results in the literature. In addition, the highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy and the other related molecular energy values of the compound have been investigated by using the same theoretical calculations.

Monomer spectroscopic analysis and dimer interaction energies on N-(4-methoxybenzoyl)-2-methylbenzenesulfonamide by experimental and theoretical approaches

In this study, theoretical harmonic vibrational frequencies and geometric parameters of N-(4-methoxybenzoyl)-2-methylbenzenesulfonamide have been investigated by Hartree-Fock (HF), density functional theory (B3LYP hybrid functional) methods with 6-311++G (d,p) basis set, for the first time. Experimental FT-IR (400-4000cm(-1)) and Laser-Raman spectra (100-4000cm(-1)) of title compound in solid phase have been recorded. Interaction energies, N-H⋯O hydrogen bonds, C-H⋯O and aromatic π⋯π stacking interactions in dimer structures of the title compound have been evaluated by the calculation methods. The dimer calculations have aimed to present the efficacy and performance of M06-2X hybrid functional on the intermolecular interactions and more strongly bound systems for the corrected and interaction energy by the counterpoise correction procedure. The interaction energies by M06-2X approach give more stable results than HF and B3LYP, extremely. The more strongly bonds, especially, on N-H⋯O hydrogen bonds and π⋯π interaction for the both dimer structure have also supported that the M06-2X functional of density functional is more effective.

Synthesis, antibacterial, anthelmintic and anti-inflammatory studies of novel methylpyrimidine sulfonyl piperazine derivatives

A strategic synthesis of novel methylpyrimidine sulfonyl piperazines involving Suzuki coupling was designed and pharmacological activities of the compounds were evaluated. Reactions were carried out under conventional method and show good functional group transformations and high yields. Structures of the newly synthesized compounds were established by infrared spectroscopy (IR), 1H and 13C nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry (LC-MS) and elemental analysis. The compounds were tested for in vitro antibacterial activity against Escherichia coli and Staphylococcus aureus bacterial strains, anthelmintic activity using Pheretima posthuma and anti-inflammatory activity involving carrageenan induced rat paw edema model. Some compounds were proven to be potent pharmacophores.

4-[4-(Hept­yloxy)benzo­yloxy]phenyl 2-oxo-7-tri­fluoro­methyl-2H-chromene-3-carboxyl­ate

The title compound, C31H27F3O7, is a liquid crystal and exhibits enantiotropic SmA and nematic phase transitions. In the crystal, the the 2H-chromene ring system makes dihedral angles of 54.46 (17) and 7.79 (16)°, respectively, with the central benzene ring and 4-(heptyloxy)benzene ring. The three F atoms of the –CF3 group are disordered over two sets of sites, with an occupancy ratio of 0.62 (3):0.38 (3). The crystal structre features two pairs of C—H⋯O hydrogen bonds, which form inversion dimers and generate R 2 2(10) and R 2 2(30) ring patterns. C—H⋯O interactions along [100] and C—H⋯π interactions futher consolidate the packing, leading to a three-dimensional network.

(1Z)-1-(1-Benzo­furan-2-yl)ethanone oxime

The title compound, C10H9NO2, is almost planar (r.m.s. deviation for the non-H atoms = 0.027 Å) and the conformation across the C=N bond is syn. Further, the O atom of the benzofuran ring is syn to the CH3 group in the side chain. In the crystal, molecules are linked into C(3) chains propagating in [010] by O—H⋯N hydrogen bonds.

4-(Oct­yloxy)phenyl 2-oxo-2H-chromene-3-carboxyl­ate

In the title compound, C24H26O5, the 2H-chromene ring system is essentially planar, with a maximum deviation of 0.029 (2) Å from the best-fit mean plane incorporating both rings. The dihedral angle between the 2H-chromene ring system and the benzene ring is 21.00 (1)°. In the crystal, pairs of C—H⋯O hydrogen bonds generate an R 2 2(8) ring pattern. These contacts are bolstered by weaker bifurcated C—H⋯O hydrogen bonds.

4-Meth-oxy-N-[(4-methyl-phen-yl)sulfon-yl]benzamide including an unknown solvate.

In the title compound, C15H15NO4S, the dihedral angle between the benzene rings is 78.62 (16)°. In the crystal, adjacent molecules are linked along the c axis into C(4) chains through strong N—H⋯O hydrogen bonds. Molecules are further connected through C—H⋯O hydrogen bonds into a hexameric unit generating an R 6 6(66) motif. Another C—H⋯O interaction connects the molecules along the c axis, forming C(5) chains. A region of disordered electron density, most probably disordered methanol–water solvent molecules, was treated with the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155]. The formula mass and unit-cell characteristics do not take into account this disordered solvent.

Investigation of the crystal structures of N-(4-fluorobenzoyl)benzenesulfonamide and N-(4-fluoro-benzoyl)-4-methylbenzenesulfonamide

Abstract The crystal structures of two closely related compounds, namely, N-(4-fluorobenzoyl)-benzenesulfonamide (I) and N-(4-fluorobenzoyl)-4-methylbenzenesulfonamide (II) are investigated by analysing the packing patterns and intermolecular interactions, and also by Hirshfeld surface analysis. The crystal structure of each of (I) and (II) displays a two-dimensional architecture. Hirshfeld surfaces comprising dnorm surface and 2D fingerprint plots were analysed for both molecules in order to understand the relationship between the crystal structures. The analysis shows that the lengths of the observed hydrogen bonds and other intermolecular interactions in (II) are relatively shorter than those observed in (I). Further, the analysis demonstrates the predominant participation of the sulfonyl-O atom and the carbonyl-O atom as the hydrogen bond acceptors in (I) and (II), respectively.

Crystal structure of 2-(4-methyl-piperazin-1-yl)quinoline-3-carbaldehyde.

In the title compound, C15H17N3O, the aldehyde group is twisted relative to the quinoline group by17.6 (2)° due to the presence of a bulky piperazinyl group in the ortho position. The piperazine N atom attached to the aromatic ring is sp 3-hybridized and the dihedral angle between the mean planes through the the six piperazine ring atoms and through the quinoline ring system is 40.59 (7)°. Both piperazine substituents are in equatorial positions.