کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1403291 | 1501780 | 2013 | 11 صفحه PDF | دانلود رایگان |

FT Raman and IR spectra of the crystallized biologically active molecule, 5-Amino-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde (5-APHC, C11H11N3O) have been recorded and analyzed. The equilibrium geometry, bonding features and harmonic vibrational frequencies of 5-APHC have been investigated with the help of B3LYP density functional theory (DFT) method with 6-31G(d) and 6-311+G(d,p) as basis set. The calculated molecular geometry has been compared with the experimental data. The assignments of the vibrational spectra have been carried out with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field (SQM) technique. The optimized geometry shows the co-planarity of the aldehyde group with pyrazole ring. Potential energy surface (PES) scan studies has also been carried out by ab initio calculations with B3LYP/6-311+G(d,p) basis set. The red shifting of NH2 stretching wavenumber indicates the formation of N–H⋯O hydrogen bonding. 1H and 13C NMR spectra were recorded and 1H and 13C nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method. UV–Vis spectrum of the compound was recorded in the region 200–400 nm and the electronic properties HOMO and LUMO energies were calculated by time-dependent TD-DFT approach. Mulliken charges of the 5-APHC molecule was also calculated and interpreted.
► FT-IR and FT-Raman spectra of the title compound were recorded and analyzed.
► 13C and 1H NMR spectra are used to elucidate the structure.
► Experimental spectra compared with theoretically simulated spectra of 5-APHC.
► HOMO and LUMO analysis and several thermodynamic properties have been performed.
Journal: Journal of Molecular Structure - Volume 1034, 27 February 2013, Pages 325–335