Počet záznamů: 1

Helquats, helical extended diquats, as fast electron transfer systems

  1. 1.
    0341536 - UFCH-W 2011 RIV GB eng J - Článek v odborném periodiku
    Pospíšil, Lubomír - Teplý, Filip - Gál, Miroslav - Adriaenssens, Louis - Horáček, Michal - Severa, Lukáš
    Helquats, helical extended diquats, as fast electron transfer systems.
    Physical Chemistry Chemical Physics. Roč. 12, č. 7 (2010), s. 1550-1556 ISSN 1463-9076
    Grant CEP: GA ČR GA203/09/0705; GA ČR GP203/09/P502; GA MŠk ME09114; GA MŠk OC 140
    Výzkumný záměr: CEZ:AV0Z40400503; CEZ:AV0Z40550506
    Klíčová slova: reversible redox systems * self-exchange kinetics * methyl viologen
    Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
    Impakt faktor: 3.454, rok: 2010

    Helicene-viologen structural hybrids, like [5]helquat, 6,7,10,11-tetrahydrodipyrido[2,1-a:1',2'-k][2,9]phenanthrolinediium, and its four methylated derivatives, are characterized by electrochemical admittance and EPR spectroscopy. All compounds are reversibly reduced in two one-electron steps. Formal redox potentials correlate with the calculated LUMO energies. The electron transfer is coupled with a weak adsorption of the reactants. The analysis of the frequency dependence of the electrode admittance is used for the separation of Faradaic and double layer contributions and finally to the estimation of heterogeneous rate constants. Heterogeneous rate constants determined this way are in the range 0.1 to 3 cm s(-1). In all cases the second electron transfer is faster than the first redox step by a factor of three. The Frumkin correction for the acceleration by the double layer potential further amplifies this difference.
    Trvalý link: http://hdl.handle.net/11104/0184483