Search results for "Phosphore"
showing 10 items of 114 documents
Red-light-emitting electrochemical cell using a polypyridyl iridium(III) polymer.
2009
A deep-red phosphorescent ionic iridium(III) complex is prepared and incorporated into a polymer. Both the complex (1) and the polymer (2) were used as the single active material in solid-state light-emitting electrochemical cells (LECs). The devices built up using 1 and 2 emit in the deep-red region of the visible spectrum with CIE coordinates x = 0.710; y = 0.283 and x = 0.691; y = 0.289, respectively, making them one of the deepest-red emitting LECs reported. It is the first example of a polymeric LEC incorporating an ionic iridium complex, which exhibits increased stabilities compared with the device based on the small molecular weight complex.
Combined thermal evaporated and solution processed organic light emitting diodes
2011
Abstract Highly efficient, partly solution processed phosphorescent red, green and white organic light emitting diodes with small molecular weight host materials are prepared from commercially available starting compounds. Starting from an evaporated reference device, layers are stepwise replaced by solution processed layers. Replacing the evaporated hole transport layer by a solution processed polymer interlayer does not affect the performance and allows spincoating of the emissive layer after annealing of the polymer. Devices with, next to the spincoated hole injection and transport layer, a solution processed emission layer show similar characteristics and efficiencies as the reference d…
Ionic iridium complex and conjugated polymer used to solution-process a bilayer white light-emitting diode.
2013
Bilayer white light-emitting devices are prepared from solution, using an ionic orange phosphorescent organometallic complex and a neutral fluorescent conjugated polymer. Because of the very different polarity of the two components, they dissolve in orthogonal solvents, allowing for the direct deposition of the blue emitter on top of the orange emitter without the need of cross-linking or special coating methodology. Fine tuning of the layer thickness of both light-emitting layers allows for the color tuning of different types of white light.
3,3'-Bicarbazole structural derivatives as charge transporting materials for use in OLED devices
2018
In this study we report novel 3,3′-bicarbazole based charge transporting materials mainly designed for a use in systems containing phosphorescent iridium (III) complex emitters. A low-cost oxidative coupling reaction using FeCl3 was employed in the synthesis of 3,3′-bicarbazole compounds. Different derivatives of 3,3′-bicarbazole with 4-ethoxyphenyland ethyl- substituents at 9,9′- positions and (2,2-diphenylhydrazono)methyl- and 4-(dimethylamino)styryl- substituents at 6,6′- positions were synthesized. Obtained (2,2-diphenylhydrazono)methyl- derivatives exhibit glass transition temperatures that are sufficient for applications in electronic devices. Thin amorphous films of good optical qual…
Solid-state luminescence of Au-Cu-alkynyl complexes induced by metallophilicity-driven aggregation.
2012
A new series of homoleptic alkynyl complexes, [{Au2Cu2(C2R)4}n] (R=C3H7O (1), C6H11O (2), C9H19O (3), C13H11O (4)), were obtained from Au(SC4H8)Cl, Cu(NCMe)4PF6, and the corresponding alkyne in the presence of a base (NEt3). Complexes 1-4 aggregate upon crystallization into polymeric chains through extensive metallophilic interactions. The cluster that contains fluorenolyl functionalities, C13H9O (5), crystallizes in its molecular form as a disolvate, [Au2Cu2(C2C13H9O)4]·2THF. The substitution of weakly bound THF molecules with pyridine molecules leads to the complex [Au2Cu2(C2C13H9O)4]·2py (6), thus giving two polymorphs in the solid state. Such structural diversity is established through …
Preparation and Thermochromic Switching between Phosphorescence and Thermally Activated Delayed Fluorescence of Mononuclear Copper(I) Complexes
2020
Instructive, inexpensive, and environmentally friendly laboratory syntheses of two highly luminescent copper(I) complexes CuI(PPh3)2(pyR) (pyR = pyridine, 4-cyanopyridine) are described for second-year/upper-division undergraduate inorganic chemistry students. Both complexes exhibit bright thermally activated delayed fluorescence (TADF) at ambient temperature and phosphorescence at low temperature. The laboratory experiments familiarize the students with mechanochemical syntheses, cluster and complex formation, ligand substituent effects, and the fascinating phenomenon of luminescence thermochromism.
Luminescence properties of a cofacial dipalladium porphyrin dimer under argon and in the presence of dioxygen
2001
The preparation and luminescence properties of a dipalladium cofacial porphyrin dimer (DPA) Pd 2 (where DPA is the tetraanion of 1,8-bis(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrin-5-yl)anthracene) are reported and compared together with the photophysical behavior of the known monomeric (OEP)Pd and (TPP)Pd complexes. The effect of dioxygen in the presence and in the absence of the very bulky base, 1-t-butyl-5-phenylimidazole, is also investigated. The title dimer, (DPA) Pd 2, shows fluorescence and phosphorescence in the ps and ms time scale, respectively, with a global intensity lower than that of the porphyrin monomer analogues. The fluorescence sensitivity towards dioxygen quenc…
A Theoretical Insight into the Photophysics of Acridine
2001
The electronic absorption and emission spectra of acridine have been studied by means of a multiconfigurational second-order perturbation method (CASSCF/CASPT2) and its multistate extension (MS-CASPT2). The low-lying valence singlet and triplet π → π* and n → π* excited states have been computed. The location of the lowest Rydberg state (3s) has been also estimated. By optimization of the geometries of the ground and low-lying excited states and the calculation of transition energies and properties, the obtained results lead to a complete analysis and assignment of the available experimental singlet−singlet and triplet−triplet absorption spectra and to the description of the basic features …
Green-Light Activation of Push-Pull Ruthenium(II) Complexes.
2020
Abstract Synthesis, characterization, electrochemistry, and photophysics of homo‐ and heteroleptic ruthenium(II) complexes [Ru(cpmp)2]2+ (22+) and [Ru(cpmp)(ddpd)]2+ (32+) bearing the tridentate ligands 6,2’’‐carboxypyridyl‐2,2’‐methylamine‐pyridyl‐pyridine (cpmp) and N,N’‐dimethyl‐N,N’‐dipyridin‐2‐ylpyridine‐2,6‐diamine (ddpd) are reported. The complexes possess one (32+) or two (22+) electron‐deficient dipyridyl ketone fragments as electron‐accepting sites enabling intraligand charge transfer (ILCT), ligand‐to‐ligand charge transfer (LL'CT) and low‐energy metal‐to‐ligand charge transfer (MLCT) absorptions. The latter peak around 544 nm (green light). Complex 22+ shows 3MLCT phosphorescenc…
Harnessing Fluorescence versus Phosphorescence Branching Ratio in (Phenyl)n-Bridged (n = 0–5) Bimetallic Au(I) Complexes
2013
We have designed and synthesized a series of Au(I) complexes bearing either an alkynyl–(phenylene)n–diphosphine (A-0–A-3) or a (phenylene)n–diphosphine (B-1–B-5) bridge, among which the effective distance between Au(I) and the center of the emitting ππ* chromophore can be fine-tuned via the insertion of various numbers of phenylene spacers. We then demonstrated for the first time in a systematic manner the decrease of rate constant for S1 → T1 intersystem crossing (ISC) kisc as the increase of the effective distance. The results also unambiguously showed that the phosphorescence could be harvested via higher S0 → Sn (n > 1) electronic excitation, followed by fast Sn → Tm ISC and then the po…