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Helquats, helical extended diquats, as fast electron transfer systems

SYSNO ASEP	0341536
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Helquats, helical extended diquats, as fast electron transfer systems
Author(s)	Pospíšil, Lubomír (UFCH-W)_{RID, ORCID} Teplý, Filip (UOCHB-X)_{RID, ORCID} Gál, Miroslav (UFCH-W) Adriaenssens, Louis (UOCHB-X) Horáček, Michal (UFCH-W)_{RID, ORCID} Severa, Lukáš (UOCHB-X)_{RID, ORCID}
Source Title	Physical Chemistry Chemical Physics. - : Royal Society of Chemistry - ISSN 1463-9076 Roč. 12, č. 7 (2010), s. 1550-1556
Number of pages	7 s.
Language	eng - English
Country	GB - United Kingdom
Keywords	reversible redox systems ; self-exchange kinetics ; methyl viologen
Subject RIV	CF - Physical ; Theoretical Chemistry
R&D Projects	GA203/09/0705 GA ČR - Czech Science Foundation (CSF)
	GP203/09/P502 GA ČR - Czech Science Foundation (CSF)
	ME09114 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
	OC 140 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
CEZ	AV0Z40400503 - UFCH-W (2005-2011)
	AV0Z40550506 - UOCHB-X (2005-2011)
UT WOS	000274243200015
DOI	10.1039/b915148f
Annotation	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.
Workplace	J. Heyrovsky Institute of Physical Chemistry
Contact	Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196
Year of Publishing	2011

Number of the records: 1