Shafikov, Marsel Z.; Pander, Piotr; Zaytsev, Andrey V.; Daniels, Ruth; Martinscroft, Ross; Dias, Fernando B.; Williams, J. A. Gareth; Kozhevnikov, Valery N. published an article in 2021. The article was titled 《Extended ligand conjugation and dinuclearity as a route to efficient platinum-based near-infrared (NIR) triplet emitters and solution-processed NIR-OLEDs》, and you may find the article in Journal of Materials Chemistry C: Materials for Optical and Electronic Devices.Related Products of 1193-21-1 The information in the text is summarized as follows:
Near IR (NIR) emission from mol. materials is typically targeted by using more extended conjugated systems compared to visible-emitting materials. But efficiencies usually fall off due to the combined effects of increasing non-radiative and lower oscillator strengths as the energy of emissive excited states decreases. Efficient NIR-emitting organic light emitting diodes (OLEDs) are rare compared to the huge progress that has been made for visible-light devices. For organometallic emitters that contain a heavy metal ion to promote phosphorescence through the effect of enhanced spin-orbit coupling (SOC), the problem is typically exacerbated by decreased metal character in the Sn and T1 excited states as the conjugation in a bound ligand increases. Here we show how the use of a dinuclear metal complex with an extended conjugated ligand allows such effects to be mitigated compared to analogous structures with just one metal center. The complex Pt2(bis-dthpym)(dpm)2 (complex 5) is readily prepared by a double NĈ cyclometallation of 4,6-bis(dithienyl)-pyrimidine (H2bis-dthpym), with the coordination sphere of each Pt center being completed by OÔ-coordinating dipivaloylmethane (dpm). This new complex displays intense NIR emission in solution, λmax = 725 nm, with essentially no “”contamination”” by visible light <700 nm. The photoluminescence quantum yield of 0.17 in toluene at 300 K is vastly superior to that of the analogous mononuclear complex, where reduced SOC leads primarily to ligand-based fluorescence and only very weak phosphorescence. Computational results indicate that a key reason for the superior performance of the dinuclear system is a doubling of the number of higher-lying excited singlet states with which the T1 state may couple, to promote the formally forbidden phosphorescence process. Complex 5 has been evaluated as an NIR emitter in solution-processed OLEDs. An external quantum efficiency (EQE) of 3.6% is attained using 5 doped into TBP:PBD at 5% weight/weight, with a turn-on voltage of 5.6 V (at 0.01 mW cm-2). The maximum radiosity of 2.7 mW cm-2 for this device is particularly high compared to most reported NIR-emitting phosphorescent OLEDs.4,6-Dichloropyrimidine(cas: 1193-21-1Related Products of 1193-21-1) was used in this study.
4,6-Dichloropyrimidine(cas: 1193-21-1) is a member of organic chlorides. Organic chloride content in crude oil can be detected through specialized laboratory analysis. Care and attention are essential while sampling and testing.Related Products of 1193-21-1
Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia