The Electrochemical Properties of Some Alkylviologens

Abstract

Ethyl-, and butylviologens were prepared by the Menschutkin reaction of 4,4 0 -dipyridyl and 1,2-dibromoethane and 1,4-dibromobutane. Elemental analysis and 1 H-NMR spectra showed that products consisted of symmetrical and asymmetrical substituted dipyridyls. Electrochemical reduction of these compounds in KBr and HCl solutions has been studied by the voltammetry method. The reduction process proceeds through several electrochemical and protonation steps, depending on the viologen structure and pH of the solution. The process results in a film formation on the electrode surface. The film is partly electroactive in the KBr solution, but completely passive in HCl. Reaction schemes have been proposed to explain this phenomenon.

Tuning the Hydrophilic, Hydrophobic, and Ion Exchange Properties of Mesoporous TiO2

“…The above results demonstrate that high surface concentrations of a membrane-intercalating guest molecule can be achieved using combined electrostatic and hydrophobic binding modes. This approach could be further exploited to attach other electrochromic materials, electron-transfer catalysts, sensitizers, or biomolecules to TiO 2 , via combined electrostatic and hydrophobic interactions, opening new roads in the field of mesoporous TiO 2 based electrochromic displays, , solar cells, battery application, or biomimetic sensors.…”

Electrochemical pH Oscillations of Ethyl Viologen/Ionic Liquid

“…The fully reduced EV 0 accepts two hydrogen ions from water and two electrons from the Pt electrode or electrolyte. EV 0 can produce a hydrogenated neutral form (EVH 2 , the yellow neutral species) and two hydroxide ions (−OH - , electrochemically inactive) in process III . Therefore, the pH of a 0.1 M EV solution can be increased up to 11.…”

Novel Organic CT Salts of 1,3-Bis(dicyanomethylidene)indan Anion and Viologen Cations with Different Linear Alkyl Chain Lengths

“…Although the neutral TCNIH2 is colorless in solvents with low polarity, the ionic TCNIHbecomes deep blue due to expansion of π-conjugation throughout the indan system (6,7). Viologen is widely known as an electron acceptor, and it is a divalent cation (8). When TCNIHand methyl viologen were mixed to form co-crystals, remarkable CT absorption was observed (9)(10)(11).…”