The switchable phosphorescence and delayed fluorescence of a new rhodamine-like dye through allenylidene formation in a cyclometallated platinum(ii) system.

ABSTRACT: A new rhodamine-like alkyne-substituted ligand (Rhodyne) was designed to coordinate a cyclometallated platinum(ii) system. The chemo-induced "ON-OFF" switching capabilities on the spirolactone ring of the Rhodyne ligand with an end-capping platinum(ii) metal centre can modulate the interesting acetylide-allenylidene resonance. The long-lived ³IL excited state of Rhodyne in its ON state as an optically active opened form was revealed via steady-state and time-resolved spectroscopy studies. Exceptional near-infrared (NIR) phosphorescence and delayed fluorescence based on a rhodamine-like structure were observed at room temperature for the first time. The position of the alkyne communication bridge attached to the platinum(ii) unit was found to vary the lead(ii)-ion binding mode and also the possible resonance structure for metal-mediated allenylidene formation. The formation of a proposed allenylidene resonance structure was suggested to rationalize these phenomena.

SUBMITTER: Zhao S 

PROVIDER: S-EPMC8386667 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature