TY - JOUR
T1 - Polymer films on electrodes. 20. An ESR study of several spin probes incorporated into nafion
AU - Kaifer, Angel E.
AU - Bard, Allen J.
PY - 1986/1/1
Y1 - 1986/1/1
N2 - The oxidative electrochemistry of protonated 2,2,6,6-tetramethylpiperidine-1-oxyl (Tempamine, TP) has been surveyed with Pt/Nafion modified electrodes. Protonated TP was shown to incorporate into Nafion films at pH lower than 9. Its oxidation is a reversible, one-electron process occurring at E1/2 = 0.54 V vs. SCE on Pt/Nafion electrodes (ca. 120 mV less positive than E1/2 on bare Pt) and independent of the pH in the range 4-8. The ESR spectrum of Nafion-confined TP showed that the rotational correlation time was in the slow tumbling region and was estimated to be 1.2 × 10-8 s. This reveals an unusual anchoring effect by Nafion which had not been observed previously. The ESR spectra of some additional Nafion-confined spin probes such as vanadyl, manganese(II), and the cation radical of N,N,N′,N′-tetramethyl-1,4-phenylenediamme (TMPD) were also surveyed. The results indicate that the motion of a given cation within Nafion is determined by the nature of the cation itself.
AB - The oxidative electrochemistry of protonated 2,2,6,6-tetramethylpiperidine-1-oxyl (Tempamine, TP) has been surveyed with Pt/Nafion modified electrodes. Protonated TP was shown to incorporate into Nafion films at pH lower than 9. Its oxidation is a reversible, one-electron process occurring at E1/2 = 0.54 V vs. SCE on Pt/Nafion electrodes (ca. 120 mV less positive than E1/2 on bare Pt) and independent of the pH in the range 4-8. The ESR spectrum of Nafion-confined TP showed that the rotational correlation time was in the slow tumbling region and was estimated to be 1.2 × 10-8 s. This reveals an unusual anchoring effect by Nafion which had not been observed previously. The ESR spectra of some additional Nafion-confined spin probes such as vanadyl, manganese(II), and the cation radical of N,N,N′,N′-tetramethyl-1,4-phenylenediamme (TMPD) were also surveyed. The results indicate that the motion of a given cation within Nafion is determined by the nature of the cation itself.
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U2 - 10.1021/j100277a032
DO - 10.1021/j100277a032
M3 - Article
AN - SCOPUS:0042189914
VL - 90
SP - 868
EP - 873
JO - Journal of Physical Chemistry
JF - Journal of Physical Chemistry
SN - 0022-3654
IS - 5
ER -