ISSN:
1573-8353
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The thermodynamic parameters of the reaction of 1-vinyl- and 1-ethylazoles with phenol (K as,-ΔH, and -ΔS) were calculated for 1∶1 complexes with the aid of ER spectroscopy. The investigated compounds are arranged in the following order with respect to their basicities on the basis of their K as and pK a values: 1-ethylimidazole, 2-methyl-1-vinylimidazole, 1-ethylbenzimidazole, 1-vinylimidazole, 1-vinylbenzimidazole, 1-ethylpyrazole, l-ethyl-l,2,4-triazole 3,5-methyl-1-vinylpyrazole, 1-vinyl-1,2,4-triazole, 1-ethylbenzotriazole, 1-vinylbenzotriazole, and 1-vinylpyrazole. The hypsochromic shifts of the bands and the change in the extinction coefficient in the electronic absorption spectra of imidazoles and benzimidazoles in HCl solution as compared with ethanol solutions are determined by the increase in the conjugation system of the azoles rather than by their basicities.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00742460
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