Adsorption of picolinic and nicotinic acids on a silver sol surface investigated by Raman spectroscopy

Analysis of carboxylate coordination function of the isomeric lanthanide pyridinedicarboxylates by means of vibration spectroscopy

“…For interpretation of IR spectra of compounds investigated we used the data on normal coordinate treatment of PDA [6][7][8][9] and data on vibration spectra of pyridine derivatives [10].…”

UV-Raman study and theoretical analogue of picolinic acid in aqueous solution

“…It is obvious that the spectra have great changes accompanied with the pH variation, indicating the changes of the molecule structure. The vibration assignments listed in Table 1 are acquired through comparing these spectra to [15][16][17][18]. When the solution changes from alkalescent (pH 8.1) to weakly acidic (pH 5.4), the spectra are grossly similar, suggesting the basically same molecule structure.…”

“…But most of them focus on the wave range of NIR or visible, and have to mixed with silver colloid to get the enhanced Raman signal [18]. Thus, the interfering material was added into the aqueous solution, leading to the adsorption process between molecules and metal particles.…”

Surface‐Enhanced Raman Spectroscopy of Tribochemically Formed Boundary Films of Refined and Unrefined Canola Oils

“…On closer examination, it appears that the 940 cm -1 peak was in fact a doublet at 930 and 955 cm -1 . The doublet (930, 955 cm -1 ) and the broad peak at 1,377 cm -1 can be assigned to the C-COOand COOvibration of the carboxylate groups, respectively, while the peak at 235 cm -1 can be assigned to the vibration of the Ag-O bond [23][24][25][26][27][28][29][30]. It is uncertain at this point why the doublet appears for the C-COOgroup.…”

“…The appearance of the shoulder at 1,700 cm -1 , which is synonymous with the stretching of C=O [27][28][29], suggests the presence of non-dissociated carboxylate groups of unadsorbed fatty acids, i.e. carboxylates groups having the COOH structure as opposed to COO -.…”