Metathesis-type poly-exo-tricyclononenes with fluoroorganic side substituents: Synthesis and gas-transport properties

The synthesis and gas-transport properties of new metathesis-type polynorbornenes bearing fluoroorganic side groups are reported. The necessary monomers, fluorosubstituted exo-norbornene derivatives (exo-tricyclononenes), were obtained using one-step method based on stereo- and regioselective [2 + 2+2]-cycloaddition of quadricyclane and fluoroalkenes. A set of high molecular weight polymers with different side groups were prepared from the synthesized F-substituted exo-tricyclononenes over the 1-st generation Grubbs catalyst. Permeability and diffusion coefficients of various gases (He, H2, O2, N2, CO2, CH4) in these poly-exo-tricyclononenes were determined for the first time and new relationships between polymer structure and gas permeability were established. Metathesis poly-exo-tricyclononene bearing four CF3-groups in each monomer unit displayed the highest gas permeability for the tested gases among metathesis polynorbornenes with F-organic substituents reported so far.