Synthesis and Characterization of Multi-Reducing-End Polysaccharides.

Site-specific modification is a great challenge for polysaccharide scientists. Chemo- and regioselective modification of polysaccharide chains can provide many useful natural-based materials and help us illuminate fundamental structure-property relationships of polysaccharide derivatives. The hemiacetal reducing end of a polysaccharide is in equilibrium with its ring-opened aldehyde form, making it the most uniquely reactive site on the polysaccharide molecule, ideal for regioselective decoration such as imine formation.

Uncorrelated Lithium-Ion Hopping in a Dynamic Solvent-Anion Network.

Lithium batteries rely crucially on fast charge and mass transport of Li in the electrolyte. For liquid and polymer electrolytes with added lithium salts, Li couples to the counter-anion to form ionic clusters that produce inefficient Li transport and lead to Li dendrite formation. Quantification of Li transport in glycerol-salt electrolytes via NMR experiments and MD simulations reveals a surprising Li-hopping mechanism.

Photocatalyst-independent photoredox ring-opening polymerization of -carboxyanhydrides: stereocontrol and mechanism.

Photoredox ring-opening polymerization of -carboxyanhydrides allows for the synthesis of polyesters with precisely controlled molecular weights, molecular weight distributions, and tacticities. While powerful, obviating the use of precious metal-based photocatalysts would be attractive from the perspective of simplifying the protocol. Herein, we report the Co and Zn catalysts that are activated by external light to mediate efficient ring-opening polymerization of -carboxyanhydrides, without the use of exogenous precious metal-based photocatalysts.