Raman and infrared spectra of crystals obtained from an aqueous solution of piperazine and pinacol with an arbitrary molar ratio were observed and conÐrm the formation of a solid solution of (piperazine-pinacol) hexahydrate, for which the infrared and Raman bands due to piperazine molecules change a
Vibrational spectra and assignments of histamine dication in the solid state and in solution
✍ Scribed by J. A. Collado; F. J. Ramírez
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 105 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0377-0486
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✦ Synopsis
The infrared and Raman spectra of histamine dihydrochloride and its N -deuterated derivative were recorded in the solid state. Raman spectra of samples dissolved in both normal and heavy water were also obtained. A general assignment of the fundamental vibrations of this cationic species of the histamine molecule was proposed on the basis of the isotopic shifts and correlations with similar molecules. Wavenumber assignments to the imidazole stretching vibrations indicate a small increase in the ring electronic density with respect to histamine monocation, although the isotopic shifts involved lead to some differences between the two sets of normal modes. The deviations observed on comparing the Raman spectra of solid and dissolved histamine dication are not significant, agreeing with the fact that the two imidazole nitrogen sites are occupied.
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