UV-VIS- und IR-spektroskopische Untersuchungen an N-substituierten 4-Amino-7-nitrobenz-2,1,3-oxadiazolen

Autor: Hermann Matschiner, H. Heberer
Rok vydání: 1986
Předmět:
Zdroj: Journal f�r Praktische Chemie. 328:261-274
ISSN: 1521-3897
0021-8383
DOI: 10.1002/prac.19863280216
Popis: UV-VIS- and IR-Spectroscopic Studies with N-Substituted 4-Amino-7-nitro-benzofurazans Starting from spectra of parent substance benzofurazan the influence of different functional groups (NO2, OH, NH2, NHAlk, NAlk2, NHAr, NArAlk) in 4- and (or) 7-position on the shape of spectra and the intensity of individual bands was examinated. It was tried to assign spectral bands to defined absorptions in the u.v./vis and i.r. range. The long-wave band in the solution-VIS-spectra of N-substituted 4-amino-7-nitrobenzofurazans was identified as a charge-transfer band. By the use of constants α, β, and π* by Kamlet and Taft the influence of different properties of solvents was correlated with band shifts in the UV/VIS range. A qualitative correlation was found between of the long-wave band in the VIS-spectra, the polarographic half wave potential E 1/2 and the sum of polar substituent constants Σσ* of Taft. These proportions were plotted in a three-dimensional diagram.
Databáze: OpenAIRE
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