Infrared gas and matrix spectra of all eight symmetrical deutero pyrazole monomers

Infrared, Raman and NMR spectra, conformational stability, normal coordinate analysis and B3LYP calculations of 5-amino-4-cyano-3-(methylthio)-1H-pyrazole-1-carbothioamide

“…In addition, the four CAN stretching modes (m 13 at 1443 (sh), 1435 (s) and 1405 (s) cm À1 respectively which undergo frequency shifts of 15-25 cm À1 in the Raman spectrum. In agreement with the calculated bond lengths, these stretching frequencies are higher than those expected for a CN single bond and are consistent with partial p bonding character of a C'N bond.…”

“…11.008 size molecules up to 26 atoms [25][26][27]. In addition GIAO NMR DFT-B3LYP calculations have become popular aids to the interpretation of 1 H and 13 C chemical shifts [28][29][30][31][32][33][34][35][36]. Therefore, a thorough Raman, IR and NMR spectroscopic investigation is reported here complemented by B3LYP theoretical predictions [20][21][22][23][24] with bases sets up to 6-31++G(d,p) to provide novel insight on vibrational assignments and conformational stability of AMPC.…”

“…Recently amino-pyrazole derivatives were found to be potentially useful in preventing brain-protein aggregation which is the first phase in the development of Alzheimer's disease [10]. The vibrational assignment of pyrazole itself has been investigated; [11][12][13][14][15][16] however, there is little information regarding vibrational spectra and structure of substituted pyrazoles and N-substituted pyrazoles in particular [17,18]. The subject of the present study, 5-amino-4-cyano-3-(methylthio)-1H-pyrazole-1-carbothioamide, (AMPC, C 6 H 7 N 5 S 2 ) has several structural characteristics: it contains linear AC"N (sp), planar ANH 2 (sp 2 ) along with tetrahedral ACH 3 (sp 3 ) moieties in addition to the pyrazole ring.…”

“…13 C NMR spectrum of AMPC, chemical shifts in ppm; (A) calculated spectrum of conformer 1 using GIAO-DFT (B3LYP/6-311+G(2d,p); (B) experimental; (C) the correlation between calculated (x-axis) and experimental peak positions.…”

Infrared, Raman and NMR spectra, conformational stability, normal coordinate analysis and B3LYP calculations of 5-Amino-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde

“…Recently amino-pyrazole derivatives were found to be potentially useful in preventing protein aggregation which in the human brain is the first phase of Alzheimer's disease development [9]. The vibrational spectra of pyrazole have been thoroughly investigated [10][11][12], however, there is relatively little information regarding substituted pyrazoles, and N-substituted pyrazoles in particular [13,14]. The inclusion of a substituent group in pyrazole leads to the variation of charge distribution in molecules and consequently this affects the structural, electronic and vibrational parameters.…”