Search results for "QD Chemistry"
showing 9 items of 19 documents
Light-emitting electrochemical cells and solution-processed organic light-emitting diodes using small molecule organic thermally activated delayed fl…
2015
EZ-C thanks the University of St Andrews for support. The authors are grateful to the EPSRC for financial support (grants EP/J01771X and EP/J00916). IDWS is a Royal Society Wolfson Research Merit Award Holder. Two novel charged organic thermally activated delayed fluorescence (TADF) emitters, 1 and 2, have been synthesized. Their TADF behavior is well-supported by the multiexponential decay of their emission (nanosecond and microsecond components) and the oxygen dependence of the photoluminescence quantum yields. Spin-coated electroluminescent devices have been fabricated to make light-emitting electrochemical cells (LEECs) and organic light-emitting diodes (OLEDs). The first example of a n…
Deep-blue thermally activated delayed fluorescence (TADF) emitters for light-emitting electrochemical cells (LEECs)
2017
The authors acknowledge the University of St Andrews for financial support. The authors also acknowledge financial support from the European Union H2020 project INFORM (grant 675867), the Spanish Ministry of Economy and Competitiveness (MINECO) via the Unidad de Excelencia María de Maeztu MDM-2015-0538, MAT2014-55200 and the Generalitat Valenciana (Prometeo/2016/135). MLP acknowledges support from a Grisolia grant (GRISOLIA/2015/A/146). Two deep blue thermally activated delayed fluorescence (TADF) emitters ( imCzDPS and imDPADPS ) that contain charged imidazolium groups tethered to the central luminophore were designed and synthesized as small molecule organic emitters for light-emitting e…
Fluorine-free blue-green emitters for light-emitting electrochemical cells
2014
Date of Acceptance: 29/05/2014 There is presently a lack of efficient and stable blue emitters for light-emitting electrochemical cells (LEECs), which limits the development of white light emitting systems for lighting. Cyclometalated iridium complexes as blue emitters tend to show low photoluminescence efficiency due to significant ligand-centred character of the radiative transition. The most common strategy to blue-shift the emission is to use fluorine substituents on the cyclometalating ligand, such as 2,4-difluorophenylpyridine, dFppy, which has been shown to decrease the stability of the emitter in operating devices. Herein we report a series of four new charged cyclometalated iridium…
Enhancing the photoluminescence quantum yields of blue-emitting cationic iridium(iii) complexes bearing bisphosphine ligands
2016
EZ-C acknowledges the University of St Andrews for financial support. We thank Johnson Matthey and Umicore AG for the gift of materials and Cihang Yu for the preparation of isopropxantphos. We thank Dr. Nail Shaveleev for the synthesis of NMS25. IDWS and AKB acknowledge support from EPSRC (EP/J01771X). This work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO) MAT2014-55200. Herein we present a structure-property relationship study of thirteen cationic iridium (III) complexes of the form of [Ir(C^N)2(P^P)]PF6 in both solution and the solid state through systematic evaluation of six bisphosphine (P^P) ligands (xantphos, dpephos, dppe, Dppe, nixantphos and is…
Green phosphorescence and electroluminescence of sulfur pentafluoride-functionalized cationic iridium(III) complexes
2015
EZ-C acknowledges the University of St Andrews for financial support. We report four cationic iridium(III) complexes [Ir(C^N)2(dtBubpy)](PF6) that have sulfurpentafluoride-modified 1-phenylpyrazole and 2-phenylpyridine cyclometalating (C^N) ligands (dtBubpy = 4,4'-di-tert-butyl-2,2'-bipyridyl). Three of the complexes were characterized by single-crystal X-ray structure analysis. In cyclic voltammetry, the complexes undergo reversible oxidation of iridium(III) and irreversible reduction of the SF5 group. They emit bright green phosphorescence in acetonitrile solution and in thin films at room temperature, with emission maxima between 482–519 nm and photoluminescence quantum yields of up to 7…
Data Underpinning - Tuning the emission of cationic iridium (III) complexes towards the red through methoxy substitution of the cyclometalating ligand
2015
EZ-C acknowledges CFI (Canadian Foundation for Innovation), NSERC (the Natural Sciences and Engineering Research Council of Canada), FQRNT (Le Fonds québécois de la recherche sur la nature et les technologies) and the University of St Andrews for financial support. C. R-C. would like to thank the MINECO for the financial support of this research in the framework of project CTQ2010-17481, the Junta de Andalucía (CICyE) for special financial support (P08-FQM-4011 and P10-FQM-6703) and the MECD (Spanish Ministry of Education, Culture, and Sport) for an FPU grant. This work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO) (MAT2014-55200), the Generalitat Valenc…
Hen and egg problems of biology from TGD point of view
2022
Biology has several hen and egg problems. What came first: DNA,RNA, amino-acids or proto-cell membrane? Did metabolism precede genetic code or vice versa? The stimulus leading to this article could have been the finding that organic molecules are formed in interstellar space at ultralow temperatures of few Kelvin in which chemistry should freeze completely. Therefore the formation of glycine peptides, which has been demonstrated in the laboratory, should be impossible. The paradox disappears in the TGD framework as do also the hen and egg problems. Magnetic body carrying dark matter as $h_{eff}=nh_0$ phases allows a universal realization of genetic code and of the analogs of basic bio-molec…
Bent-core liquid crystalline cyanostilbenes: fluorescence switching and thermochromism
2015
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Crystal structure of [tris(4,4-bipyridine)]diium bis(1,1,3,3-tetracyano-2-ethoxypropenide) trihydrate
2016
In the title hydrated salt, which was obtained from the hydrothermal reaction between between potassium 1,1,3,3-tetracyano-2-ethoxypropenide and 4,4′-bipyridine in the presence of iron(II) sulfate heptahydrate, the ionic components are linked into a three-dimensional network by C—H⋯N hydrogen bonds.