RESUMEN

In this study the experimental and theoretical vibrational frequencies of a newly synthesized anti-tumor, antiviral, hypoglycemic, antifungal and anti-HIV agent namely, 5-Methyl-3-phenylisoxazole-4-carboxylic acid has been investigated. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-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 by using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr and DFT/M06-2X: highly parametrized, empirical exchange correlation function) with 6-311++G(d,p) basis set by Gaussian 09W software, for the first time. The assignments of the vibrational frequencies have been done by potential energy distribution (PED) analysis by 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 by using the same theoretical calculations.

Asunto(s)

RESUMEN

The asymmetric unit of title compound, C12H12N2O4, consists of two independent mol-ecules. In each mol-ecule, the oxadiazine ring has a flattened envelope conformation with the methyl-ene C atom as the flap atom, and the eth-oxy-carbonyl unit is in a syn-periplanar conformation with respect to the oxadiazine ring as indicated by O-C-C=O torsion angles of 1.9 (4) and 2.5 (4)°. The dihedral angles between the mean plane of the oxadiazine ring and the phenyl ring are 80.07 (13) and 42.98 (14)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds and stacked in a double-column along the a-axis direction.

RESUMEN

In the title compound, C11H9NO3, the phenyl and isoxazole rings form a dihedral angle of 56.64 (8)°. The carb-oxy group is almost in the same plane as the isoxazole ring with a C-C-C-O torsion angle of -3.3 (2)°. In the crystal, pairs of O-H⋯O hydrogen bonds link the mol-ecules into head-to-head dimers. C-H⋯N hydrogen bonds and π-π stacking inter-actions between phenyl rings [centroid-centroid distance = 3.9614 (17)Å] link the dimers into a three-dimensional network.

RESUMEN

In the title compound, C12H11NO4, the dihedral angle between the benzene and isoxazole rings is 42.52 (8)°. The carb-oxy-lic acid group is close to being coplanar with the isoxazole ring [dihedral angle = 5.3 (2)°]. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R2(2)(8) loops.

RESUMEN

The asymmetric unit of the title compound C25H19N5OS, contains two mol-ecules, A and B. In mol-ecule A, the dihedral angles between the pyrazole ring and the C-bound phenyl group, the N-bound phenyl group and the thia-diazole ring are 32.30 (14), 52.25 (14) and 34.94 (12)°, respectively. The corresponding angles in mol-ecule B are 33.32 (14), 50.67 (15), and 70.30 (12)°, respectively. In the crystal, the A and B mol-ecules are linked by pairs of N-H⋯N hydrogen bonds, generating R 2 (2)(8) loops. This dimer linkage is reinforced by two C-H⋯O hydrogen bonds and one C-H⋯N hydrogen bond.

RESUMEN

In the title compound, C24H20N4O2, the pyrazole ring makes dihedral angles of 47.57 (10)° and 30.56 (11)° with its N-bound and C-bound phenyl groups, respectively. The C-N-N-C group that links the two carbonyls has a torsion angle of 81.5 (2)°. The torsion angles between the carbonyl groups and their adjacent pyrazole and phenyl rings are 125.89 (19) and 164.22 (17)°, respectively. In the crystal, pairs of mol-ecules are linked by N-H⋯O hydrogen bonds into R 2 (2)(10) ring motifs, which in turn link to form chains that propagate parallel to the c-axis direction.

RESUMEN

In the mol-ecule of the title compound, C(16)H(16)N(4)O, the pyrazole ring makes dihedral angles of 8.52 (13) and 9.26 (12)° with the phenyl rings. The dihedral angle between the benzene rings is 1.86 (13)°. In the crystal, mol-ecules are linked into centrosymmetric dimers via pairs of O-H⋯N hydrogen bonds. Weak N-H⋯N inter-actions connect the dimers into a chain along the [100] direction. The pyrazole ring adopts a highly flattened envelope conformation.

RESUMEN

In the title compound C(11)H(9)NO(2), the phenyl and isoxazole rings are almost coplanar, making a dihedral angle of 1.14 (9)°. This planarity is also assisted by an intra-molecular C-H⋯O hydrogen bond between the phenyl ring and the carbonyl O atom. In the crystal, weak C-H⋯O inter-actions generate a layered structure parallel to the ac plane.