A Novel Photoinduced Ligation Approach for Cross-Linking Polymerization, Polymer Chain-End Functionalization, and Surface Modification Using Benzoyl Azides.

Various ligation processes have recently become a powerful tool in synthetic polymer chemistry. Herein, the use of a new photochemical ligation process as a versatile approach for the cross-linking polymerization, functionalization of polymer chain ends, and surface modification of various materials such as silica and graphene oxide, is demonstrated. The process is based on the formation of urethane linkages by the reaction of photochemically in situ generated isocyanates from benzoyl azides with hydroxyl moieties in the presence of organobase, bicyclo[2.2.2]-1,4-diazaoctane (DABCO) under ambient conditions. The intermediates and obtained materials are characterized by NMR, FTIR, TGA, and TEM analyses. It is believed that this simple and efficient ligation process will expand future applications to fabricate complex macromolecular structures, biomaterials, and gels.