Molecular structure and vibrational assignment of 2-,4-,6-methylquinoline by density functional theory (DFT) and ab initio Hartree-Fock (HF) calculations

Factors Controlling Adsorption Equilibria from Solution onto Solid Surfaces: The Uptake of Cinchona Alkaloids on Platinum Surfaces

“…RAIRS traces obtained for all seven quinoline derivatives adsorbed onto platinum surfaces from CCl 4 solutions are shown in Figure , and the corresponding peak assignments, made with the aid of reported data for quinoline, − monosubstituted quinoline, , cinchonidine, − cinchonine, and quinine, as well as quantum mechanical calculations carried out in our own laboratory, are reported in Table . Notice that most of the peaks in the infrared spectral window reported here correspond to in- plane stretchings or deformations of the quinoline ring, with a few notable exceptions (including vibrations in the methoxy group of 6-methoxyquinoline, quinine, and quinidine).…”

Infrared Spectra of Dimethylquinolines in the Gas Phase: Experiment and Theory

“…Thus, we need to consider anharmonic force constants that include the cubic and quadratic terms in order to get close agreement with experiment. Another way to improve the agreement between experimental and calculated vibrational frequencies is to take calculated harmonic frequencies and make correction for systematic errors by means of some scaling procedure. , Ozel et al did exactly that. They used HF and B3LYP levels of theory with the 6-31++G (d,p) basis set for the calculation of the IR spectra of 2-, 4-, and 6-methylquinolines.…”

“…15 Ozel et al have carried out DFT calculations and assignment of the fundamental vibrational bands of the NIST listed spectra of MQs. 16 Infrared spectra of 2,8-DMQ and trimethylquinolines (TMQs) in CS 2 solution have also been reproted. 17 Generally both harmonic and anharmonic DFT calculations have been carried out in the literature to assign experimental IR spectra of large aromatic molecules.…”

“…Identification and quantitative analysis of DMQs and MQs in ambient air and in sediments have been done using flame ionization detection-gas chromatography (FID-GC) coupled with GC-MS and HRGC-MS, respectively. , Low-resolution IR spectra of several MQs are available in the NIST-IR spectral library . Ozel et al have carried out DFT calculations and assignment of the fundamental vibrational bands of the NIST listed spectra of MQs . Infrared spectra of 2,8-DMQ and trimethylquinolines (TMQs) in CS 2 solution have also been reproted …”

Comparative vibrational spectroscopic studies of 7-chloro-4- hydroxy-3-quinolinecarboxylic acid based on density functional theory

“…The introduction of one or more substituent in quinoline ring leads to the variation of charge distribution in the molecule, and consequently, this greatly affects the structural, electronic and Vibrational parameters. Though there are few studies on quinoline compounds [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], the structural characteristics and vibrational spectroscopic analysis of 7-chloro-4-hydroxy-3-quinolinecarboxylic acid by the quantum mechanical HF and DFT methods have not been studied. Thus, considering the industrial and biological importance of 7-chloro-4-hydroxy-3-quinolinecarboxylic acid, an extensive experimental and theoretical study on 7C4H3QCA to obtain a complete reliable and accurate vibrational, electronic transitions assignments and structural characteristics of the compound has been made.…”