A photoswitchable organocatalyst controls trimethylene carbonate and δ -valerolactone copolymerization

Switchable catalysts can be reversibly altered to produce two (or more) states displaying orthogonal activities. The use of compounds containing a “switchable” unit in ring opening polymerization (ROP) of cyclic esters and ethers has been an attractive area of research due to the biosourced and biodegradable nature of the polymers produced and enhanced control of the polymer structure. Such systems for ROP have been reported using various stimuli such as temperature, redox or chemical reagents, electrodes, and, recently, light.