Side-chain boron difluoride formazanate polymers via ring-opening metathesis polymerization

The synthesis, characterization, and ring-opening metathesis polymerization (ROMP) of a novel norbornene-based boron difluoride (BF2) formazante monomer are described in detail. The polymerization studies confirmed ROMP to occur in the presence of BF2 formazanates, and also demonstrated the controlled nature of the polymerization. The polymers retained many of the unique characteristics of the monomers in dichloromethane, including absorption and emission at maximum wavelengths of 518 and 645 nm, large Stoke's shifts (upsilon(ST) = 127 nm, 3800 cm(-1)), and the ability to act as electron reservoirs to form borataverdazyl-based poly(radical anions) (E-red1 degrees = -0.95 V). Furthermore, the results described in this paper demonstrate the potential of these and related polymers based on BF2 formazanates as redox-active, light-harvesting materials.