Multiple Emission of Phosphonium Fluorophores Harnessed by the Pathways of Photoinduced Counterion Migration
Journal
Angewandte Chemie - International Edition
Journal Volume
61
Journal Issue
19
Date Issued
2022
Author(s)
Abstract
In the emerging field of intramolecular charge transfer induced counterion migration, we report the new insights into photophysical features of luminescent donor–acceptor phosphonium dyes (D−π−)nA+[X−] (π=−(C6H4)x−). The unique connectivity of the phosphorus atom affords multipolar molecules with a variable number of arms and the electronic properties of the acceptor group. In the ion-paired form, the transition from dipolar to quadrupolar configuration enhances the low energy migration-induced band by providing the additional pathways for anion motion. The multipolar architecture, adjustable lengths of the π-spacers and the nature of counterions allow for efficient tuning of the emission and achieving nearly pure white light with quantum yields around 30 %. The methyl substituent at the phosphorus atom reduces the rate of ion migration and suppresses the red shifted bands, simultaneously improving total emission intensity. The results unveil the harnessing of the multiple emission of phosphonium fluorophores by anion migration via structure and branching of donor–acceptor arms. © 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.
Subjects
Charge Transfer; Donor–Acceptor Systems; Dual Emission; Ion Pairs; Phosphonium
SDGs
Other Subjects
Electronic properties; Fluorophores; Ions; Phosphorus; Red Shift; Counterions; Donor-acceptor system; Donor/acceptor; Dual emissions; Intra-molecular charge transfer; Intramolecular charge transfers; Ion pairs; Phosphonia; Phosphorus atom; Photo-induced; Charge transfer
Type
journal article