System for Living ROMP of a Paramagnetic FeCl 4 - -Based Ionic Liquid Monomer: Direct Synthesis of Magnetically Responsive Block Copolymers.

Direct, living ring-opening metathesis polymerization of a highly paramagnetic, norbornene-based imidazolium FeCl 4 - ionic liquid monomer was achieved using the Grubbs third-generation catalyst and starting the polymerization off with an uncharged, nonparamagnetic norbornene monomer in a sequential block copolymerization. Preparing the paramagnetic norbornene imidazolium FeCl 4 - monomer in high purity was found to be crucial for enabling living polymerization behavior and generating paramagnetic diblock copolymers with predictable block lengths and compositions.