Search results for "Iridium"

An inconvenient influence of iridium(III) isomer on OLED efficiency.

2010

The recently reported heteroleptic cyclometallated iridium(III) complex [Ir(2-phenylpyridine)(2)(2-carboxy-4-dimethylaminopyridine)] N984 and its isomer N984b have been studied more in detail. While photo- and electrochemical properties are very similar, DFT/TDDFT calculations show that the two isomers have different HOMO orbital characteristics. As a consequence, solution processed OLEDs made using a mixture of N984 and isomer N984b similar to vacuum processed devices show that the isomer has a dramatic detrimental effect on the performances of the device. In addition, commonly used thermogravimetric analysis is not suitable for showing the isomerization process. The isomer could impact pe…

The promoter effect of Nb species on the catalytic performance of Ir-based catalysts for VOCs total oxidation

2022

12 figures, 2 tables.-- Supporting information available.

Development of accurate mass spectrometric routine and reference methods for the determination of trace amounts of iridium and rhodium in photographi…

1999

For the determination of trace amounts of iridium and rhodium in photographic emulsions different sample treatment procedures were coupled with inductively coupled plasma mass spectrometry (ICP-MS) and, for iridium, also with negative thermal ionisation isotope dilution mass spectrometry (NTI-IDMS) and ICP-IDMS. IDMS determinations of iridium were carried out using an enriched 191Ir spike solution. Elimination of the silver matrix was established for both mass spectrometric methods, which prevents corresponding memory effects in the ICP-MS system and is essential for the formation of IrO2 - thermal ions, respectively. For NTI-MS measurements, the gelatine matrix of the emulsion must also be…

An Unprecedented Iridium(III) Catalyst for Stereoselective Dimerisation of Terminal Alkynes

2008

A novel iridium(III) hydride complex, IrHCl(TIMP 3 ) {HTIMP 3 = tris[1-(diphenylphosphino)-3-methyl-lH-indol-2-yl]methane) was prepared and fully characterized in both the solid state and in solution. Chloride abstraction by silver cations provides a more reactive compound, [IrH-(TIMP 3 )][BF 4 ], which can react with pyridine (py) and phenylacetylene to yield the complexes [IrH-(TIMP 3 )(py)][BF 4 ] and [Ir(PhCH=C-CH=CHPh)-(TIMP 3 )][BF 4 ], respectively. Interestingly, IrH-(TIMP 3 )(py)][BF 4 ] efficiently catalyses the stereoselective dimerisation of model terminal alkynes to the 1,4-disubstituted (E)-but-1-en-3-yne only.

Stable Green Electroluminescence from an Iridium Tris-Heteroleptic Ionic Complex

2012

An ionic tris-heteroleptic iridium complex gives green light-emitting electrochemical cells (LECs) with unprecedented performances for this part of the visible spectrum. The devices are very bright (>1000 cd m–2), efficient (∼3%), and stable (>55 h). The novel complex is prepared using a new and efficient synthetic procedure. We show that there is a mixed orbital formation originating from the two different orthometalating ligands resulting in photophysical properties that lie between those of its two bis-heteroleptic analogs. Therefore, tris-heteroleptic complexes provide new avenues for fine-tunning the emission properties and to bridge gaps between a series of bis-heteroleptic complexes.

Hydrogenation of White Phosphorus to Phosphane with Rhodium and Iridium Trihydrides.

1998

Only one of the four P atoms of P4 reacts with rhodium and iridium trihydrides [(triphos)MH3 ] to provide phosphane [Eq. (a)]. The resulting cyclo-P3 fragment is efficiently scavenged by the metal fragment to give the complexes [(triphos)M(η3 -P3 )]. A mechanism accounting for the hydrogenation reaction is proposed in which the complexes [(triphos)MH(η1 :η1 -P4 )] and [(triphos)M(η1 :η2 -HP4 ] are intermediates. The latter complex contains the unprecedented hydridotetraphosphane ligand HP4- .

<title>Iridium L<formula><inf><roman>3</roman></inf></formula>-edge and oxygen K-edge x-ray absorption spec…

2003

Structural investigations of the short range order around iridium and oxygen ions in nanocrystalline iridium oxide thin films, prepared by dc magnetron sputtering technique, were performed by x-ray absorption spectroscopy. The Ir L3-edge extended x-ray absorption fine structure and the O K-edge x-ray absorption near edge structure signals were measured at room temperature and analyzed within ab initio multiple-scattering and full-multiple-scattering approaches, respectively. The x-ray absorption spectroscopy results indicate the presence in the films of orderd regions - nanocrystals, having a size of about 10 angstrom and a structure rather close to that in crystalline iridium oxide IrO2. S…

CCDC 1857871: Experimental Crystal Structure Determination

2018

Related Article: Marta Martínez-Alonso, Natalia Busto, Larry Danilo Aguirre, Leticia Berlanga, M. Carmen Carrión, José V. Cuevas, Ana M. Rodríguez, Arancha Carbayo, Blanca R. Manzano, Enrique Ortí, Félix A. Jalón, Begoña García, Gustavo Espino|2018|Chem.-Eur.J.|24|17523|doi:10.1002/chem.201803784

Racemization of Secondary-Amine-Containing Natural Products Using Heterogeneous Metal Catalysts

2018

CCDC 1583689: Experimental Crystal Structure Determination

2018

Related Article: Aron J. Huckaba, Alessia Senes, Sadig Aghazada, Azin Babaei, Stefan C. J. Meskers, Iwan Zimmermann, Pascal Schouwink, Natalia Gasilova, René A. J. Janssen, Henk J. Bolink, Mohammad Khaja Nazeeruddin|2018|ACS Omega|3|2673|doi:10.1021/acsomega.8b00137