Viologen (2+/1+) and viologen(1+/0) electron-self-exchange reactions in a redox polymer
- Univ. of North Carolina, Chapel Hill (United States)
An analysis is given of the electron-self-exchange reactions responsible for the steady-state redox conductivity of thin films of the electropolymerized monomer N,N{prime}-bis(3-pyrrol-1-yl-propyl)-4,4{prime}-bipyridinium tetrafluoroborate, sandwiched between two electrodes. Concentration-gradient-driven electron self-exchange in the liquid-acetonitrile-bathed viologen(2+/1+) mixed-valent state of this polymer, k{sub ex} = 8 {times} 10{sup 3} M{sup {minus}1}s{sup {minus}1}, is much slower than that for the viologen (1+/0) mixed-valent state, k{sub ek} = 1.6 {times} 10{sup 5} M{sup {minus}1} s{sup {minus}1}, which has a smaller activation barrier. Neither self-exchange reaction responds to use of alternative counteranions except that both rates decrease in polymer containing tosylate counterions. The rate constant found for the electrical-gradient-driven viologen (1+/0) electron self-exchange, k{sub ex} = 1.1 {times} 10{sup 5} M{sup {minus}1} s{sup {minus}1}, observed in dry, N{sub 2}-bathed polymer where ClO{sub 4}{sup {minus}} counterion mobility is quenched, is nearly the same as the acetonitrile-bathed value. The rate constants appear to be dominated by characteristics of the polymer phase rather than the bathing environment of the polymer. Estimates are made of the counteranion diffusivity in acetonitrile-bathed films and of how it effects transient electron transport measurements.
- OSTI ID:
- 7017228
- Journal Information:
- Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:16; ISSN 0022-3654; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microelectrode voltammetry and electron transport in an undiluted room temperature melt of an oligo(ethylene glycol)-tailed viologen
Redox photochromism in films of viologens and related compounds bearing long-chain alkyl groups
Related Subjects
400400* -- Electrochemistry
ACTIVATION ENERGY
ANIONS
CHARGE STATE
CHARGED PARTICLES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DATA
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON TRANSFER
ENERGY
EXPERIMENTAL DATA
INFORMATION
ION MOBILITY
IONS
KINETICS
MOBILITY
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC POLYMERS
OXIDATION
PARTICLE MOBILITY
PHYSICAL PROPERTIES
POLYMERS
REACTION KINETICS
REDUCTION