Infrared Absorption of Aqueous Solutions of Organic Acids and Their Salts

Abstract

All isomers, except 3-and 5-cyclohexyleicosane, have the strongest maximum in the 9.0-9.5 µ bands at approximately 9.29 µ. The maximum is at 9.245 µ for 3-cyclohexyleicosane and at 9.23 µ for 5-cyclohexyleicosane. The latter isomer is the only one to have a band at 11.60 µ. 7-Cyclohexyleicosane is the only member of the series which has an absorption maximum at 12.73 µ, although a few of the isomers have broad shoulders near this wave length. 9-Cyclohexyleicosane has a sharp maximum at 8.96 µ which is equal in intensity to the 8.88 µ band. Moreover, this isomer has a broad shoulder at about 11.42 µ, which is also conspicuous in 9-cyclohexylheptadecane. CONCLUDING REMARKSIt has not been an object of the present work to determine the purity of the compounds investigated. To do so would have required a detailed consideration of the method by which each compound was synthesized and of the impurities likely to occur in it, as well as observation of the absorption spectrum of each compound at different stages of purification. Although the results obtained in comparing the various spectra with one another and with the spectra of related compounds indicate that the purity is high, it would not be surprising if one or more of the weaker absorption maxima observed should be found to have been caused by impurities. Nevertheless, the spectra presented here should be adequate for estimating the possibilities and limita-tions of the application of infrared spectroscopy to the identification of phenyl-and cyclohexyleicosanes and to the analysis of mixtures containing these compounds. ACKNOWLEDGMENTSThe writers wish to acknowledge their indebtedness to the American Petroleum Institute, and to the late F. C. Whitmore and R. W. Schiessler of Pennsylvania State College, for the loan of the hydrocarbons. One of the authors (K. S.) wishes to express her gratitude to the Ethyl Corporation for the grant of a fellowship. LITERATURE CITED

Co-assemblies of polydiacetylenes and metal ions for solvent sensing

“…31,33 In the FTIR spectra of TDA/Ni and TDA/Zn, there are broad bands at 1644 and 1638 cm À1 , respectively, which come from vibrations of water molecules in the two samples. 34 As the drying processes of these two samples are the same as the other samples without such a peak, there should be no free water molecules in these two samples. The vibration peak probably comes from water molecules coordinated with Ni 2+ and Zn 2+ , or hydrated carboxylate ions.…”

Infrared spectra of aqueous sodium benzoates and salicylates in the carboxyl-stretching region: chelation in aqueous sodium salicylates

“…Similarly, an infrared band near 1580 cm-' was assigned to the asymmetric stretching frequency. Gore, Barnes, and Petersen found corresponding peaks at 1410 and 1560 cm-' in the infrared spectra of sodium acetate in deuterium oxide solution (20), and Erlich found peaks at 1412 and 1550 cm-' for sodium polymethacrylate in the same solvent (21).…”

Photoelectrochemical Complete Decomposition of Cellulose for Electric Power Generation

“…After the light irradiation, new IR absorption bands appeared around 1400 and 1500-1600 cm À 1 , which can be assigned as the symmetric and the asymmetric COO À stretchings, respectively. [37][38][39] The intensity of the symmetric COO À stretching around 1400 cm À 1 obviously increased according to the prolonged light illumination, whereas the absorption of the asymmetric COO À stretch around 1500-1600 cm À 1 immediately increased during the initial stage of the PEC reaction, then gradually decreased over time (Figure 6b). The typical carboxyl acid determined as intermediate products, such as formic acid and acetic acid, showed a strong absorption of the asymmetric COO À stretch and quite weak absorption of the symmetric stretching.…”