Vinyl-containing complex, reductive polymerization

In subsequent years, electropolymerization was definitely the established procedure. Polymerization by cathodic reduction, even exploiting redox mediation at the electrode, has been carried out on a wide series of Fe(II), Ru(II), and Os(II) vinyl-containing complexes based on differently substituted pyridine, and the relevant polymerization mechanism was extensively discussed in the same article [13]. An element of complexity of the RPs electrochemical growth hes in the presence, in the monomer, of additional electroactive groups. 

Meyer and coworkers investigated the photophysical behavior of vinyl containing Ru(II) and Os(II) complexes electropolymerized into the channels of silica sol-gel modified ITO electrodes. The monomeric complexes, [Ru(vbpy)3]2+ and [Os(vbpy)3]2+ (vbpy = 4-methyl-4/-vinyl-2,2/-bipyridine), have excited state lifetimes of approximately 900 and 60 ns, respectively. Incorporation into the sol-gel pores and polymerization (reductive polymerization initiated at the ITO electrode) results in chromophores that exhibit a remarkably small amount of self-quenching and have domains that reflect relatively isolated chromophores with excited state lifetimes longer than the solution values [125]. 

Electropolymerization of 4-Vinylpyridine Complexes. Investigations of Structural and Electronic Influences on Thin Film Formation. The recent discovery of the reductive polymerization of complexes containing vinylpyridyl ligands (lg), such as Ru -(bpy)2(vpy)22+ has led to the preparation of homogeneous thin layers of very stable electroactive polymers. This method has been extended to 4-vinyl-4 -methyl-2,2 -bipyridine (lg, 21a) and 4-vinyl-l,10-phenanthroline (21b) on both ruthenium and iron. In the following section we discuss our results on thin films derived from the polymerizable ligands BPE and the trans-4 -X-stilbazoles, (4 -X-stilb X - Cl, OMe, CN and H). 

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