A dual catalysis system was developed to synthesize hydrolyzable polyether–polyester copolymers from propylene oxide and cyclic esters such as γ-butyrolactone, δ-valerolactone, and ε-caprolactone. A bimetallic chromium catalyst active for the enantioselective polymerisation of propylene oxide and an organocatalyst active for the ring-opening polymerisation of lactones were used in conjunction with an alcohol chain shuttling agent to create new copolymers. The monomer and alcohol ratios were varied to yield a wide range of copolymers with varying monomer ratios, molecular weights, and crystallinities. [ABSTRACT FROM AUTHOR]
Clayman NE, Manumpil MA, Matson BD, Wang S, Slavney AH, Sarangi R, Karunadasa HI, and Waymouth RM
Inorganic Chemistry [Inorg Chem] 2019 Jul 31. Date of Electronic Publication: 2019 Jul 31.
We report the reactivity of copper azobispyridine (abpy) metallopolymers with nitrogen dioxide (NO2). The porous and conductive [Cu(abpy)]n mixed-valence metallopolymers undergo a redox reaction with NO2, resulting in the disproportionation of NO2 gas. Solid- and gas-phase vibrational spectroscopy and X-ray analysis of the reaction products of the NO2-dosed metallopolymer show evidence of nitrate ions and nitric oxide gas. Exposure to NO2 results in complete loss of porosity and a decrease in the room-temperature conductivity of the metallopolymer by four orders of magnitude with the loss of mixed-valence character. Notably, the porous and conductive [Cu(abpy)]n metallopolymers can be reformed by reducing the Cu-nitrate species.