We report a new class of C∧C* platinum(II) complexes in which excimer formation enhances the quantum yield while shortening the phosphorescence lifetime. Selective excitation of the monomer or dimer could be achieved at different wavelengths. These complexes exhibit strong phosphorescent emissions in the blue part of the visible spectrum around 450 nm with quantum yields of up to 93%. The emission behavior is controlled through the steric demand of the substituents at the 2,4-pentanedione ligand. We see dual emission with high photoluminescence quantum yields (PLQY) from monomeric and aggregated excited states.

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In this work we describe the synthesis and the photophysical and electrochemical characterization of binuclear PtII complexes. Using a modular click chemistry approach, we decorated different flexible bridging units with (bpy)PtII bisacetylides (bpy = 2,2′-bipyridine). Intramolecular excimer formation originating from PtII–PtII and π–π interactions was investigated by steady-state and time-resolved emission spectroscopy in dilute solution. We observed that linkers bringing the metallic centers in close proximity favor both ground-state coupling and excimer formation. These interactions lead to changes in the photophysical and electrochemical properties, which can be tuned by the choice of solvent.

The synthesis of a family of differently substituted 5-and 4,4Ј-ethynyl-bpy Pt II bisacetylide complexes (bpy = 2,2Ј-bipyridine) and their postfunctionalization using click chemistry is described. Cu I -catalyzed azide-alkyne [3+2] cycloaddition was an efficient method to decorate the Pt II complexes with a manifold of moieties in high yields. The absorption and emission properties and the electrochemical behaviour of all of the complexes have been investigated. The studied compounds emit at room temperature between 598 and 660 nm, reaching photoluminescence quantum yields of 0.33 in solution. The bright luminescent properties of the unsub-[a] Institute We intended to find out if (a) the method is adaptable to Pt II coordination compounds, even in the presence of coordinated acetylide units, and (b) how the resulting triazolyl subsitutents influence the photophysical properties. Therefore, we synthesized a series of different ethynyl-and triazolyl-substituted bpy Pt II bisacetylides and investigated their absorption, emission and electrochemical properties. Furthermore, we successfully used two representative derivatives as dopants in solution-processed polymer-based light-emitting devices (PLEDs). The performance of the simple devices, using polyvinylcarbzole (PVK) as a host matrix and the Pt II complexes as dopants, proved that the compounds are also suitable for electroluminescence. Results and Discussion SynthesisThe complexes can be categorized into two series, namely, 5-substituted and 4,4Ј-disubstituted bpy Pt II bisacetylides. The bpy ligands, 5-(trimethylsilylethynyl)-2,2Ј-biwww.eurjic.org