Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Más filtros

Bases de datos
Tipo del documento
Asunto de la revista
País de afiliación
Intervalo de año de publicación
1.
Acta Crystallogr E Crystallogr Commun ; 78(Pt 8): 789-793, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-35974835

RESUMEN

In the fused ring system of the title mol-ecule, C31H35NO4, the conformation of the central di-hydro-pyridine ring is inter-mediate between boat and envelope with the N and the opposite C atoms lying out of the basal plane. The conformations of terminal rings are close to envelope, with the atoms substituted by two methyl groups as the flaps. In the crystal, the mol-ecules are linked by O-H⋯O hydrogen bonds into helical chains. The Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (63.2%), O⋯H/H⋯O (20.1%) and C⋯H/H⋯C (14.4%) contacts. Quantum chemical calculations of the frontier mol-ecular orbitals were carried out to characterize the chemical reactivity of the title compound.

2.
Front Plant Sci ; 13: 906207, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35898223

RESUMEN

Globally, maize is an important cereal food crop with the highest production and productivity. Among the biotic constraints that limit the productivity of maize, the recent invasion of fall armyworm (FAW) in India is a concern. The first line of strategy available for FAW management is to evaluate and exploit resistant genotypes for inclusion in an IPM schedule. Screening for resistant maize genotypes against FAW is in its infancy in India, considering its recent occurrence in the country. The present work attempts to optimize screening techniques suited to Indian conditions, which involve the description of leaf damage rating (LDR) by comparing injury levels among maize genotypes and to validate the result obtained from the optimized screening technique by identification of lines potentially resistant to FAW under artificial infestation. Exposure to 20 neonate FAW larvae at the V5 phenological stage coupled with the adoption of LDR on a 1-9 scale aided in preliminary characterize maize genotypes as potentially resistant, moderately resistant, and susceptible. The LDR varies with genotype, neonate counts, and days after infestation. The genotypes, viz., DMRE 63, DML-163-1, CML 71, CML 141, CML 337, CML 346, and wild ancestor Zea mays ssp. parviglumis recorded lower LDR ratings against FAW and can be exploited for resistance breeding in maize.

3.
Acta Crystallogr E Crystallogr Commun ; 76(Pt 4): 585-588, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32280509

RESUMEN

In the fused ring system of the title compound, C32H37NO4, the central di-hydro-pyridine ring adopts a flattened boat conformation, the mean and maximum deviations of the di-hydro-pyridine ring being 0.1429 (2) and 0.2621 (2) Å, respectively. The two cyclo-hexenone rings adopt envelope conformations with the tetra-substituted C atoms as flap atoms. The benzene and phenyl rings form dihedral angles of 85.81 (2) and 88.90 (2)°, respectively, with the mean plane of the di-hydro-pyridine ring. In the crystal, mol-ecules are linked via an O-H⋯O hydrogen bond, forming a helical chain along the b-axis direction. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (65.2%), O⋯H/H⋯O (18.8%) and C⋯H/H⋯C (13.9%) contacts. Quantum chemical calculations for the frontier mol-ecular orbitals were undertake to determine the chemical reactivity of the title compound.

4.
Acta Crystallogr E Crystallogr Commun ; 71(Pt 2): o117-8, 2015 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-25878860

RESUMEN

In the title compound, C15H18N2O5, the meth-oxy-phenyl ring makes a dihedral angle of 84.70 (12)° with the mean plane of the tetra-hydro-pyrimidin-2(1H)-one ring. Both the pyran and tetra-hydro-pyrimidin-2(1H)-one rings have distorted envelope conformations with the carboxyl-ate-substituted C atom as the flap. In the crystal, mol-ecules are linked via pairs of N-H⋯O hydrogen bonds, forming zigzag chains propagating along [010], which enclose R (2) 2(8) ring motifs. The chains are linked by C-H⋯π inter-actions, forming a two-dimensional network parallel to (100).

5.
Spectrochim Acta A Mol Biomol Spectrosc ; 146: 261-72, 2015 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-25819314

RESUMEN

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of (E)-5-benzylidene-2-thioxothiazolidine-4-one (E5BTTO) have been investigated experimentally and theoretically based on Density Functional Theory (DFT) approach. The FT-Raman and FT-IR spectra of E5BTTO were recorded in solid phase. Theoretical calculations were performed at the DFT level using the Gaussian 03 program. The experimental bands were assigned and characterized on the basis of the scaled theoretical wavenumber by their Total Energy Distribution (TED). The results of the calculation were applied to simulate infrared and raman spectra of the title compound which showed good agreement with the observed spectra. The calculated HOMO and LUMO energies show that charge transfer occur within the molecule. Stability arising from hyperconjugative interactions leading to its NLO activity and charge delocalization were analyzed using Natural Bond Orbital (NBO) analysis.


Asunto(s)
Modelos Químicos , Modelos Moleculares , Rodaminas/química , Rodaminas/síntesis química , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 144: 243-57, 2015 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-25769121

RESUMEN

The experimental and theoretical vibrational frequencies of a newly synthesized compound, namely 1-(quinolin-3-yl)piperidin-2-ol (QPPO) are analyzed. The experimental FT-IR (4000-400 cm(-1)) and FT-Raman (4000-100 cm(-1)) of the molecule in solid phase have been recorded. The optimized molecular structure, vibrational assignments of QPPO have been investigated experimentally and theoretically using Gaussian03W software package. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The first order hyperpolarizability (ß0) is calculated to find its character in non-linear optics. Gauge including atomic orbital (GIAO) method is used to calculate (1)H NMR chemical shift calculations were carried out and compared with experimental data. The electronic properties like UV-Visible spectral analysis and HOMO-LUMO energies were reported. The energy gap shows that the charge transfer occurs within the molecule. Thermodynamic parameters of the title compound were calculated at various temperatures.


Asunto(s)
Modelos Moleculares , Piperidinas/química , Piperidinas/síntesis química , Teoría Cuántica , Quinolinas/química , Quinolinas/síntesis química , Electrones , Entropía , Conformación Molecular , Dinámicas no Lineales , Presión , Espectroscopía de Protones por Resonancia Magnética , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática , Temperatura , Vibración
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA