Interpretation of IR spectra of the N-acethyl-4-dimethylaminopyridinium salts

In a harmonic approximation we calculate the frequencies of normal vibrations and their modes for a salt cation of N-acethyl-4-dimethylaminopyridinium hexachlorstibiate and of its three deuteroderivatives obtained on deuteration over a CH₃-group, over a ring, and over a ring and a CH₃-group. From the results of calculation, an interpretation of the IR spectra of the salts considered is carried out. To whom correspondences should be addressed. L. M. Litvinenko Institute of Physical and Organic Chemistry and the Chemistry of Coal, National Academy of Sciences of Ukraine, 70, R. Luxemburg Str., Donetsk, 340114, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 2, pp. 158–162, March–April, 1999.     

Vibrational spectrum of pyridine hydrochloride

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 56, No. 2, pp. 222–228, February, 1992.     

Concerning the nature of the doublet at 2200 cm−1 in the vibrational spectra of cyanoguanidine

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 55, No. 1, pp. 53–57, July, 1991.     

Investigation of azomethine group vibrations in aromatic schiff bases and their N-oxides by vibrational spectroscopy methods

The effects of fluorine substitution in benzene rings and quaternization of the nitrogen atom in Schiff bases of the general formula R−CH=N−R′ on the vibration characteristics of the azomethine group are analyzed. Normal vibrations and intensities of IR bands are calculated. It is shown that the spectroscopic behavior of the C=N bond is almost independent of the electronic effects of substituents in the benzene rings of the molecules studied, and the changes in the intensities of ν_C=N bands are caused by interactions between vibrations. This points to the stability of this bond in the series of molecules under consideration. For diphenylnitrones, N→O vibrations are identified. L. M. Litvinenko Institute of Physical Organic Chemistry and Carbon Chemistry. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 2, pp. 310–315, March–April, 1995. Translated by L. Smolina