Polymerization-induced clusteroluminescence of poly(cyclic carbonate)s†

Abstract

As a rising star in the area of soft luminescent materials, clusteroluminescence (CL) polymers without large π-conjugated structures have received considerable attention in recent years owing to their great theoretical significance and potential applications. Herein, poly(vinylene carbonate) (PVC) and poly(vinylethylene carbonate) (PVEC) containing only oxygen heteroatoms are prepared and exhibit blue photoluminescence (PL) with excitation/molecular weight-dependent and concentration-enhanced emission properties. The PL quantum yields of PVC and PVEC in dimethyl sulfoxide can reach 11.5% and 13.1%, respectively. The experimental results show that CL will appear above the critical degree of polymerization (DP); within a certain range of DP, the quantum yield increases rapidly with increasing DP, and eventually tends to be constant, confirming the theory of polymerization-induced emission (PIE). Theoretical calculations reveal that the high molecular weight can greatly promote the formation of oxygen clusters and the through-space n–n interaction (TSI-n–n) of oxygen atoms, while the rigid molecular conformation further stabilizes them, enabling fluorescence emission. Moreover, benefiting from the ultra-high molecular weight (1436.7 KDa) of PVC, electrospun fibers, electrosprayed microspheres, and sponges were prepared, providing a new platform for the rational molecular design of functional CL materials.