ISSN:
0009-2940
Keywords:
Quinoxalinium salts
;
Redox systems
;
Electrochemistry
;
Radical cations
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Electrochemical and Spectroscopic Characterization of N,N′-Dialkylquinoxalinium Redox SystemsThe outstanding position of the 1,4-isomer, quinoxaline, among the diazanaphthalenes is confirmed by comparing LUMO energies from HMO perturbation calculations. Diquaternary salts [(R+)2(quin)](X-)2, R = Me, Et; quin = quinoxaline, 2,3- and 6,7-dimethyl- and 2,3,6,7-tetramethylquinoxaline, X- = BF4- or SbCl6- (4a - g), were isolated and characterized as compounds which are sensitive to reduction and hydrolysis. Cyclic voltammetry of the two-step redox systems of the Weitz type showed two reversible one-electron reductions with an extraordinarily stable radical cation intermediate (lg Kc 12). The redox potentials are less negative than those of the 4,4′-bipyridinium systems but also less positive in comparison to the values of N,N′-dialkylphenazinium compounds. The radical cation intermediates which include a TCNQ- salt cannot only be characterized by ESR, but also by absorption spectroscopy in comparison to the respective dications.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19911240121
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