Phenanthroline iridium complex

The iridium complex [lr(OMe)(cod)2] with 4,4 -di-tert-butyl-2,2 -bipyridine (dtbpy) or 2,9-diisopropyl-l,10-phenanthroline (dipphen) as ligand shows a catalytic activity for aromatic C—H silylation of aromatic compounds by disilane [60]. The reac-hon of 1,2-dimethylbenzene 135 with l,2-di-tert-butyl-l,l,2,2,-tetrafluorodisilane... 

A range of metal catalysts have also been studied in aqueous solution for the transformation of carbon dioxide, including rhodium, ruthenium and iridium bipyridine or phenanthroline complexes.One of the most effective systems is the iridium complex shown in Figure 3.14. The ligand design concept used in this study is very clever. The catalytic activity of the complex and its solubility in aqueous solution can be tuned by the pH of the solution.Under acidic... 

A related iridium complex has been used for the decarbo)grlative radical allylation of aminoacids and phenylacetic acids that occurs smoothly at room temperature in the presence of Pd(PPh3)4, irradiating by white LEDs. The proposed scheme (Scheme 6) is based on dual catalysis. Ruthenium tris(phenanthroline) dichloride has been used for visible light catalysis of the mild amidation of ketoacids by ort/zo-substituted anilines using ozygen as terminal oxidant (Scheme 7) ... 

A broad range of metal centers have been used for the complexation of functional ligands, including beryllium [37], zinc, transition metals such as iridium [38], and the lanthanide metals introduced by Kido [39], especially europium and terbium. Common ligands are phenanthroline (phen), bathophenanthrolin (bath), 2-phenylpyridine (ppy), acetylacetonate (acac), dibenzoylmethanate (dbm), and 11 thenoyltrifluoroacetonate (TTFA). A frequently used complex is the volatile Eu(TTFA)3(phen), 66 [40]. 

The reaction of a 1,10-phenanthroline complex of iridium, [Ir(cod)-(phen)]+, with dioxygen in methanol solution has been studied (38). When the anion for this cationic complex is chloride, no anion-cation interaction occurs, and the iridium system remains four-coordinate. However, when either iodide or thiocyanate is present due to the addition of their sodium salts (or in the presence of added triphenylphos-phine when the anion is chloride), the iridium system becomes five-coordinate because of the interaction between I", SCN", or PPh3 and the iridium center. These five-coordinate systems react more rapidly with dioxygen than did the four-coordinate system at both normal and elevated pressures. An end-on oxidative addition of the dioxygen moiety, with displacement of the , SCN, or PPh3 ligands, was postulated. 

The preparation of bis(bipyridyl) (702) and bis(phenanthroline) cobalt(III) complexes (576) has been the subject of a number of papers. Interest centers on the possibility of cis-trans isomerism in these complexes, since it would seem that the close approach of the 6,6 -(bipyridyl) and 2,9-(phenanthroline) protons in the trans complex would make this stereochemistry unattractive for central ions such as co-balt(III), rhodium(III), or iridium(III). Cis complexes are well established, but a violet compound claimed to be anionic cobalt(II) species (21, 573, 591). 

The complex serves as a useful intermediate for the preparation of other iridium(I) complexes, because the p-toluidine ligand can be readily displaced at room temperature by pyridine or 1,10-phenanthroline.2 An additional carbon monoxide ligand is replaced with triphenylphosphine, -arsine, and -stibine as well as with phosphites and ethylenebis[diphenylphosphine].2... 

ES tuning effects on photophysical properties are quite evident in the luminescence spectrum of the iridium(III) complex ion Ir(Mephen)2ClJ (Mephen = 5,6-dimethyl-1,10-phenanthroline) in ambient-temperature dimethylformamide. This displays dual emission from thermally equilibrated MLCT and LF states. Increased pressure (300 MPa) leads to enhanced MLGT emission (550 nm) at the expense of the LF emission (720 nm) with little or no shift of peak maxima (Fig. 

The level schemes for [Ru(phen)3] and [Os(phen)3] (phen == 1,10-phenanthroline) are representative of the clusters of low lying electronic states that arise from dv configurations of many ruthenium (II), osmium (II), and iridium (III) complexes. They are highly unusual since they have decay parameters that lie between the ranges expected for conventional singlet and triplet states and because of the magnitudes of the splittings themselves. These parameters control the nature of dir" ... 

The complex ion, cw-dichlorobis-4,7-dimethyl-l,10-phenanthroline iridium (III) chloride [IrCl2(4,7-mephen)2]Cl, has luminescence properties which are intermediate between the aforementioned homo-bischelated complexes (23). The emitting levels of this complex are best classified as nearly equal admixtures of cItt and tttt configurations. The luminescence lifetime at 77 °K ranges from 208 to 22 fisec as the solvent polarity is decreased. The quantum yield of 0.62 in ethanol-methanol glass at 77°K indicates an intrinsic radiative lifetime of 35 /msec under these conditions. The number of equilibrated levels responsible for the emission of this complex as in the previous case, has not been determined. 

Figure 1. Molecular orbital energy level diagram for homo-bischelated complexes of iridium(III) with 1,10-phenanthroline, 4,7-dimethyl-1,lO-phenanthro-line, and 5,6-dimethyl-l,10-phenanthroline...

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