Premium
Photophysical Enhancement of Triplet Emitters by Coordination‐Driven Self‐Assembly
Author(s) -
Zhang Yuzhen,
Fulong Cressa Ria P.,
Hauke Cory E.,
Crawley Matthew R.,
Friedman Alan E.,
Cook Timothy R.
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201700614
Subject(s) - intersystem crossing , quantum yield , phosphorescence , carbene , photochemistry , metallacycle , chemistry , bipyridine , quantum efficiency , platinum , reaction rate constant , crystallography , materials science , physics , catalysis , fluorescence , excited state , kinetics , crystal structure , organic chemistry , atomic physics , optoelectronics , x ray crystallography , quantum mechanics , diffraction , singlet state , optics
The quantum yields of organic fluorophores used as donors in coordination‐driven self‐assembly often suffer from the heavy atom effect of nearby metal sites. Here, the role of intersystem crossing from a deactivating process to one that delivers emissive triplet states was reversed. A phosphorescent trans bis‐ N ‐heterocyclic carbene platinum(II) compound, Pt(dhim) 2 (C≡C‐4‐py) 2 ( D1 ; dhim=1,3‐dihexyl‐2‐H‐imidazol‐2‐ylidene), was used along with other linear donors 4,4′‐bipyridine ( D2 ) and 1,4‐bis(4‐pyridyl ethynyl)benzene ( D3) in self‐assembly reactions with Pt(dtbpy)X 2 acceptors (dtbpy=4,4′‐di‐tert‐butyl‐2,2′‐bipyridine) to afford three metallacycles. Photophysical investigations revealed that, although the building blocks used to construct M1 have relatively low quantum yields ( Φ =1.2 and <1 % for D1 and 2 , respectively), the metallacycle has a quantum yield of 14 %. This increase reflects a change in radiative rate constant from 3.6×10 4 s −1 for D1 to 2.1×10 5 s −1 for M1 .