Molecular Phosphorescence in Polymer Matrix with Reversible Sensitivity

• DOI: 10.1021/acsami.0c04859
• Publication Date: 2020-04-10T08:20:36Z
• Authors: Hongwei Wu; Long Gu; Glib V. Baryshnikov; Hou Wang; Boris F. Minaev; Hans Ågren; Yanli Zhao
• Keywords: Matrix (chemical analysis)

Ultralong organic phosphorescence strongly depends on the formation of aggregation, while it is difficult to obtain in dilute environments account excessive internal and external molecular motions. Herein, ultralong single-molecule (USMP) at room temperature was achieved monomer state by coassembling biphenyl naphthalene derivatives low density with poly(vinyl alcohol) (PVA), where PVA provides a confined environment stabilize triplet state. Various factors that affect USMP were studied, including conformation, temperature, moisture. In these systems, aggregates through intermolecular stacking hydrogen bonding interactions film or crystal phases completely suppresses USMP. However, fluorescence enhanced when compounds high concentration becomes stronger their powder state, indicating intersystem crossing process blocked aggregation. Theoretical calculations suggest aggregation depresses spin-orbit coupling between excited singlet states enhances nonradiative quenching process. Moreover, relatively twisted conformation more conducive occurrence than planar conformation. The shows delicate reversible sensitivity changes moisture, rendering them applicability as smart optoelectronic materials.