Département de chimie moléculaire

Electrodes modified by thin films of polypyrroles functionalized by a $μ$-oxo binuclear manganese complex [(L)2MnIII($μ$-O)2MnIV(L)2]3+ (L = 4-(4-pyrrol-1-yl-butyl)-4'-methyl-2,2'-bipyridine) have been prepd. following two indirect routes. The first consists of a carefully controlled electropolymn. of the mononuclear [MnII(L)3]2+ complex in CH3CN soln. Under these conditions, the electro-induced dimerization of the [Mn(L)3]2+ complex into [Mn2O2(L)4]3+ occurs probably prior to electropolymn. of the pyrrole groups. The second route involves the initial formation of a polyLH+ film by electropolymn. of the ligand L in acidic conditions. The polyLH+ film is transformed into poly[Mn(L)3]2+ by complexation with Mn2+ cations in DMSO soln. The electro-induced dimerization of this mononuclear complex into [Mn2O2(L)4]3+ is efficient only if the cond. of the polypyrrole framework is preserved. Nevertheless, this transformation can be achieved in CH3CN electrolyte contg. a small amt. of DMSO acting as a mediator for electrodes having no cond. [on SciFinder(R)]