Beilstein J. Org. Chem.2018,14, 1459–1481, doi:10.3762/bjoc.14.124
design that underpins the successful achievement of improved photophysical features and enhanced device performances will be highlighted. Special emphasis will be devoted to those recent systems that have been employed as triplet emitters in efficient PhOLEDs.
Keywords: cyclometalatingligands
nonradiative deactivation channels [25][44].
Nevertheless, the use of multidentate chromophoric ligands that are able to provide metal–ligand bonds with higher covalent character, as for instance cyclometalatingligands, has proven to be a successful strategy for improving the luminescence properties due to
, together with the use of heterocyclic moieties such as thiophene or carbazole, clearly favours the luminescence properties of these type of platinum(II) complexes [68].
As aforementioned, N-deprotonable azole units constitute a compelling alternative to C-cyclometalatingligands [16]. In this regard
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Graphical Abstract
Figure 1:
Molecular structure of neutral platinum(II) complex 1 bearing four monodentate ligands; cy = cycloh...
Beilstein J. Org. Chem.2018,14, 664–671, doi:10.3762/bjoc.14.54
demonstrated. Phenyl-substituted N-heterocyclic carbenes (NHCs) as C^C* cyclometalatingligands shift the emission color towards higher energy, due to the strong donor character of NHCs compared to C^N cyclometalatingligands [33][34]. Recently, it was shown that the introduction of sterically demanding aryl
groups as substituents in acetylacetonate (acac) auxiliary ligands can have a positive influence on the emission properties of platinum(II) phosphors [35][36][37][38]. The use of mesityl and duryl groups enhanced the quantum yield of platinum complexes with a variety of C^C* cyclometalatingligands [18