Bicyclic guanidinium tetraphenylborate: a photobase generator and a photocatalyst for living anionic ring-opening polymerization and cross-linking of polymeric materials containing ester and hydroxy groups.

1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD) with pKa of 26.03 in acetonitrile can be effectively released by photolysis of TBD.HBPh4 salt, which represents a new family of short-wave UV photobase generators. This photobase generator enables the photoinduced living ring-opening polymerization of cyclic esters and the photoinduced cross-linking of various polymeric materials containing the hydroxyl-ester groups.