High‐molecular‐weight polysulfates are readily formed from aromatic bis(silyl ethers) and bis(fluorosulfates) in the presence of a base catalyst. The reaction is fast and proceeds well under neat conditions or in solvents, such as dimethyl formamide or N‐methylpyrrolidone, to provide the desired polymers in nearly quantitative yield. These polymers are more resistant to chemical degradation than their polycarbonate analogues and exhibit excellent mechanical, optical, and oxygen‐barrier properties.

Functional polystyrenes and polyacrylamides, containing combinations of fluorosulfate, aromatic silyl ether, and azide side chains, were used as scaffolds to demonstrate the postpolymerization modification capabilities of sulfur(VI) fluoride exchange (SuFEx) and CuAAC chemistries. Fluorescent dyes bearing appropriate functional groups were sequentially attached to the backbone of the copolymers, quantitatively and selectively addressing their reactive partners. This combined SuFEx and CuAAC approach proved to be robust and versatile, allowing for a rare accomplishment: triple orthogonal functionalization of a copolymer under essentially ambient conditions without protecting groups.

A handful of high fidelity reactions are at the core of industrial processes producing polymers in multimillion-ton quantities. Most commodity polymers are synthesized from olefins by forming carbon-carbon backbones, whereas engineering polymers are commonly prepared via condensation reactions of monomers often containing an activated carbonyl group or its equivalent and a suitable nucleophile, thus forming carbon-heteroatom linkages. Polyesters, polyamides, polyurethanes, and polyimides are produced in this manner. Despite the variety of backbone structures, polymers containing sulfur(VI) "-SO 2 -" connectors are virtually absent from the literature and are barely used in industrial applications (with the exception of polysulfones, in which the sulfone group is already present in the monomers [1] ).Unsurprisingly, most reported attempts to synthesize sulfur(VI)-containing polymers relied on reactions mimicking carbonyl group-based condensations, i.e. reactions of sulfonyl chlorides with nucleophiles [2] and, to a much lesser extent, Friedel-Crafts sulfonylations. [3] While polymers obtained by those methods can have attractive properties, such as good thermal and hydrolytic stability and mechanical resilience, [2c-e] the unselective reactivity of sulfur(VI) chlorides, which are susceptible to hydrolysis and participate in redox transformations and radical chlorinations, significantly limit the utility of these methods and materials.Sulfur(VI) fluorides, in particular sulfuryl fluoride (SO 2 F 2 ) and its monofluorinated derivatives, sulfonyl (RSO 2 -F) fluorides, sulfamoyl (R 2 NSO 2 -F) fluorides, and fluorosulfates (ROSO 2 -F) stand in stark contrast to other sulfur(VI) halides. These sulfur oxofluorides are much more hydrolytically stable, redox silent, and do not act as halogenating agents. Nevertheless, their selective reactivity can be revealed when an * fokin@scripps.edu Homepage: http://www.scripps.edu/fokin; sharples@scripps.edu Homepage: http://www.scripps.edu/sharpless. Supporting information for this article is available on the WWW under http://www.angewandte.org or from the authors. The formation of sulfonyl-heteroatom bonds is described in detail in an accompanying article in this issue. [5] In the early 1970s, Firth pioneered the synthesis of poly(arylsulfate) polymers from fluorosulfates of Bisphenol A (BPA), which he obtained from SO 2 F 2 , and disodium salts of the bisphenol. [6] Preparation of these monomers required prolonged heating, and pure high polymer was obtained only after repeated precipitation. Here, we report a simple and straightforward SuFEx-based method for the synthesis of high molecular weight polysulfate polymers from aryl fluorosulfates and aryl silyl ethers under simple and mild reaction conditions. HHS Public AccessReactions of silylated and fluorinated compounds are, of course, well known in organic synthesis [7] and in polymer chemistry. [8] For example, in 1983, Kricheldorf introduced the "silyl method" for the synthesis of polyaryl ethers taking advantage of the str...

No abstract

A new family of poly(ethylene glycol) (PEG) based membranes for CO2 separation was developed using thiol–ene photopolymerization. Compared to photopolymerized PEG-containing acrylate membranes, these new thiol–ene based membranes offer improved mechanical properties and processing advantages. The starting material, a combination of a trithiol cross-linker and a PEG diene, was gradually modified with a PEG dithiol while maintaining 1:1 thiol:ene stoichiometry. This approach made it possible to decrease the network cross-link density, resulting in simultaneous increases in free volume and PEG content. Materials with high concentrations of dithiol were very stretchable, with largely, up to 500%, improved elongation at break, yet they exhibited commendable CO2/N2, O2, H2, and CH4 permeability-selectivity performance. The average molecular weight of polymer chains between cross-links, M c, was determined experimentally by fitting the classic network affine model to stress–strain data obtained via tensile testing. M c was also calculated assuming an ideal, lattice-like, network structure based on monomer stoichiometry. The effect of M c on glass transition temperature and gas permeation behavior was studied. A free volume based model was employed to describe experimental gas permeability (diffusivity) trends as a function of M c.