ISSN:
0075-4617
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Two-Step Redox Systems, XI1). - Diquaternary Salts of Bipyridyls and Dipyridylethylenes: Syntheses and PolarographyThe partly newly synthesized redox systems 2Ox, 2BOx, 3Ox and 4Ox were studied by polarography. In water only the first reduction steps Ox/Sem (=E2) can be observed. However, in dimethylformamide and acetonitrile the steps Sem/Red (=E1) were observed for the first time as being reversible in so far as Red has a “quinonoid” structure. The semiquinone formation constant K of 2, 2B and 4 (107-1010) drops to about 103 in 3 when a vinylene group is introduced between the pyridine rings.
Notes:
Die teilweise neu synthetisierten Redoxsysteme 2Ox, 2BOx, 3Ox und 4Ox werden polarographisch untersucht. Während in Wasser nur die ersten Reduktionsstufen Ox/Sem (=E2) eindeutig auftreten, sind in Dimethylformamid und Acetonitril erstmals auch die Stufen Sem/Red (=E1) reversibel gemessen worden, sofern sich die Red-Form der Systeme “chinoid” formulieren läßt. Die Semichinonbildungskonstante K von 2, 2B und 4 (107-1010) sinkt bei Einschiebung einer Vinylengruppe zu 3 auf ca. 103 ab.
Additional Material:
17 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.197319730220
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