Effects of tris (phenanthroline)-iron(III) complex on the polymerization of styrene

The polymerization of styrene initiated by 2,2′ azobisisobutyronitrile had been studied in N,N-dimethylformamide at 60°, in the presence of Tris(phenanthroline)-iron(III) perchlorate. The complex was prepared in situ by mixing phenanthroline with hexakis (N,N-dimethylformamide) iron(III) perchlorate in the ratio 3:1. The nature of the complex formed was established by Job's method. The equilibrium constant for

$\text{Fe}{}^{\mathrm{3+}}\text{+ 3}\text{Phen}\text{?}\text{Fe(Phen)}{}_3\text{]}{}^{\mathrm{3+}}$

is 2·3 × 10² 1³ mol^?3. The velocity constant at 60° for the reaction of polystyryl radical with Fe(Phen)₃]³⁺ is 2·93 × 10⁴ mol^?1 l s^?1.