High-efficiency deep-red to near-infrared emission from Pt(ii) complexes by incorporating an oxygen-bridged triphenylborane skeleton

Abstract

Due to the limitation of energy gap law, platinum(II) complexes simultaneously with long luminous wavelength and high efficiency are still confronted with challenge. In order to better understand the effect...

Cationic tetraphenylethylene-based AIE-active acrylonitriles: investigating the regioisomeric effect, mechanochromism, and wash-free bioimaging

“…We also measured the fluorescence lifetime and estimated their radiative and nonradiative decay rate (Table 1) according to a previous study. 54 Compared with o -TPE-ANPy + and p -TPE-ANPy + , m -TPE-ANPy + exhibited a relatively short lifetime and strong nonradiative decay rate, which indicated that the molecules of m -TPE-ANPy + tended to move freely in the solution. In contrast to the faint emissions in solution, the fluorescence of these compounds in the solid state was remarkably boosted, due to the restriction of intramolecular motion (RIM).…”

Photoluminescence of a Platinum(II) Complex Containing Multiresonance B–N Motif in the Cyclometalated Ligand

“…As depicted in Figure a, the Pt atom adopts an ideal square-planar coordination geometry. The Pt–C and Pt–N bond lengths of 1.975 and 1.983 Å are similar to those in cyclometalated Pt­(C ∧ N)­(acac) complexes (C ∧ N denotes C -deprotonated phenylpyridine ligand and its derivatives), − meaning they are not affected by the skeleton fusion with an MR segment. The mesityl group is found to be largely twisted with respect to the ligand plane (torsion angle: ca.…”

“…This finding further confirms the emission as phosphorescence instead of TADF. In the literature, platinum­(II) complexes with the general formula of Pt­(C ∧ N)­(acac) represent an important class of triplet emitters. − It can be found that the triplet radiative decay rates of Pt­(BICPy)­(acac) and the prototypical Pt­(C ∧ N)­(acac) complexes are comparable, while the color purity of the former is significantly improved. As a common strategy to improve the emission color purity, the use of highly rigid pincer or tetradentate ligands has been proven feasible by suppressing the vibrational coupling between the excited state and ground state. − Therefore, the inclusion of a MR motif in the cyclometalating ligand provides a contribution to this end.…”