Iridium complexes pyridyl

Just as with nondoped red fluorescent dyes, nondoped phosphorescent iridium complexes consisting of two chelating phenyl-substituted quinazoline and one (2-pyridyl) pyrazolate or triazolate have recently been reported by Chen et al. (278-280) (Scheme 3.88) [308]. All of these complexes exhibited bright red phosphorescence with relatively short excited state lifetimes of 0.4-1.05 ps. PHOLEDs fabricated using the compounds A and B with relatively... 

Bis[iV,iV -di(2-pyridyl)-imidazol-2-ylidene]aurate(I) tetrafluoroborates, preparation, 2, 292-293 Bis[iV,iV -di(2-pyridyl-methyl)-imidazol-2-ylidene]aurate(I) tetrafluoroborates, preparation, 2, 292-293 Bis(diselenolate) complexes, dinuclear iron compounds, 6, 242 Bis(dithiolene) compounds, in tungsten carbonyl and isocyanide complexes, 5, 644 Bis(enolato) complexes, with bis-Cp Ti(IV), 4, 589 Bis(enones), in reductive cyclizations, 10, 502 Bis(ethanethiolato) complexes, with bis-Cp Ti(IV), 4, 601 Bis(ethene)iridium complexes, preparation, 7, 328-329 -Bis(fluorenyl)zirconocene dichlorides, preparation,... 

Several reports have dealt with the 3,6-bis(2-pyridyl)-l,2,4,5-tetrazine (bptz) ligand reactions of bptz with first-row transition metals have been explored <05JA12909> the synthesis and crystallographic study of a dinuclear iridium complex have been published <051CA1317> and a new molecular propeller compoimd prepared from the reaction of bptz with Ag[AsFe] has been reported <05CC46>. 

Iridium complexes with triphenylphosphine modified with poly(ethylene oxide)s 14 at one of the phosphine groups were active in two-phase hydrogenation of allylbenzene, although the catalyst activity and selectivity with respect to the hydrogenation product, propylbenzene, was substantially lower than in the case of its low molecular analogue and one of the main products was propenylbenzene. Similar results were obtained for an iridium complex with polyethylene oxide modified with pyridyl groups [53],... 

Iridium Complexes. PVK can be doped with a phosphine cyano irid-ium(III) complex. The complex shows a blue emission at both 467 and 496 nm caused by triplet transitions of states built between metal and ligand and those built in the ligand only. An iridium complex with the ligands of A, A -di(4-ten-butylphenyl)-4-(2-pyridyl) phenylamine and ac-etylacetone shows green phosphorescence at 533 nm in a blend of PVK and PBD. A maximum external quantum efficiency 10% photons per electron at a current density of 32 mAcm is achieved. 

Direct C-H activation at abnormal carbene positions was achieved by heteroatom-directed cyclometalation reactions using pyridyl-functionalized azolium salts and [IrCp Cl2]2 (Cp = pentamethylcyclopentadienyl Scheme 3.4). Cyclometalation proceeded well with both triazolium salt 20 and imidazolium salt 22 and yielded iridium complexes 21 and 23 in good yields. Transmetalation from silver was not efficient in either case. The imidazolium precursor underwent activation and oxidation of the exocyclic C2-bound CH3 group, whereas triazolium salt 20 formed a mixture of compounds upon reaction with Ag20, probably due to poor selectivity and competitive coordination of the pyridyl nitrogen. 

First attempts to isolate monocarbene-hydrido complexes by oxidative addition of A -(2-pyridyl)imidazolium cations to Pd° with utilization of the chelate effect of the donor-functionalized carbene ligand failed and only the dicarbene complexes such as 29 were isolated [112]. The iridium hydrido complex 30 was obtained in the oxidative addition of an W-(2-pyridylmethyl)imidazolium cation to iridium(I) (Fig. 11) [113]. This reaction proceeds most likely via the initial coordination of the nitrogen donor which brings the imidazolium C2-H bond in close proximity to the metal center. No reaction was observed with Rh under these conditions. 

Figure 3.14 Synthesis of rhodium and iridium pyridyl functionalised carbene complexes.

N,N,N-Tri((6-methyl-2-pyridyl)methyl)amine and N-methyl-N,N-bis ((6-methyl-2-pyridyl)methyl)amine with [(r/ -C2H4)Ir(Cl)] and potassium hexafluorophosphate in methanol give the bis(ethene) iridium(I) 151 and 152, respectively. Both readily dissociate one ethene molecule. In the case of 151, the mono-ethene 139 (M = Ir, R = Me) slowly transforms to the cyclometalated 153 in acetonitrile. The rhodium complex reacts with molecular oxygen with displacement of ethene and formation of a per-oxo-species. Both iridium mono-ethene species, in contrast, bind... 

---