Evidence of the withdrawing effect of a pyridinium N-cation on the electrochemical reduction of gold (III) tetraphenylporphyrin

Self-oriented polycationic copolymers obtained from bipyridinium meso-substituted-octaethylporphyrins

“…The potential shifts recorded for their oxidation and reduction correlate with previous data on the substituent effects [31][32].…”

Electrochemical behavior of the tetracationic porphyrins and

“…4. The two first reduction steps for ZnOEPðpyÞ 4þ 4 4Cl À (2, c = 4.5 Â 10 À4 mol L À1 ) in CH 3 CN and 0.1 mol L À1 TBAPF 6 recorded at different scan rates (between 20 and [45][46][47][48][49][50]. We can suggest that the relative stability of the dimers and/or polymers obtained here would be probably a consequence of their insolubility yielding coated electrodes.…”

“…In this case, the redox pattern of the substituted groups could be strongly modified by the influence of the porphyrin moiety [37][38][39]. That was related in studies devoted to the electrochemical reduction of various substituted pyridinium groups [45,46]. The latter generally proceeds through two successive one-electron transfers and numerous works were mainly oriented toward the conditions of reversibility of the first electron uptake [47][48][49].…”

“…Indeed the usual electrochemical pattern for the cationic 1-substituted pyridinium compounds in nonaqueous media involved an initial one electron uptake which produced the first cathodic wave and was generally followed by rapid dimerization of the free-radical products when the 4-position was free. The generated dimers were oxidized at considerably more positive potentials to the original electroactive compound [45][46][47].…”