Journal
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
Volume 141, Issue 8, Pages 3717-3722Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jacs.9b00363
Keywords
-
Categories
Funding
- NSF [CHE-1506722]
- NIH [R01 CA215157, IR01GM128037-01]
- University at Buffalo
- State University of New York (SUNY) Research Foundation
Ask authors/readers for more resources
The local environment surrounding lumino-phores can significantly influence their photophysical properties. Herein, we report the self-assembly of a highly emissive platinum(II)-based metallacage. In order to accommodate the connectivity of the platinum(II) building block used in the self assembly process, the luminophore-containing building block adopts a highly twisted geometry relative to its free form, leading to the emergence of an emissive transition with a radiative rate constant an order of magnitude higher than that of the free luminophore. This increased rate constant is the primary driver for the 10-fold increase in quantum yield from 4.2% to 40%. Model complexes with platinum or methyl groups bound to the nitrogen were synthesized. These complexes had lower quantum yields (10% and non-emissive, respectively) due mainly to decreases in radiative rate constants. Computational studies were conducted and indicated that the excited state of the ensembles, as well as the model complexes, is a result of charge transfer to the pyridyl groups, in contrast to the free luminophore, which involves the diphenyl sulfone moiety. The differences in quantum yields can be explained by a twist in the chromophore upon coordination of platinum or methylation on the pyridyl group, leading to intersystem crossing to a triplet state. This state then becomes more emissive with the addition of platinum, which increases the radiative rate constant via the heavy atom effect. The formation of a metallacage also decreases the non-radiative rate constant by inhibiting the intramolecular motions of the incorporated luminophore.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available