Organometallic chemistry iridium complexes

Organometallic chemistry of pyrrole is characterized by a delicate balance of the ti N)- and -coordination modes. Azacymantrene is an illustration of the considerable nucleophilicity of the heteroatom. However, azaferrocene can be alkylated at C2 and C3 sites. Ruthenium and osmium, rhodium, and iridium chemistry revealed the bridging function of pyrroles, including zwitterionic and pyrrolyne complex formation. The ti (CC) coordination of osmium(2- -) allows versatile derivatizations of the heteroring. 

Iridium made its first major mark in 1965, in the arena of organometallic chemistry with the discovery of Vaska s complex, [IrCl(CO)(PPh3)2] (1) [1]. Only weakly catalytic itself, Vaska s complex is nevertheless highly relevant to cataly-... 

Dihydrido Iridium Triisopropylphosphine Complexes From Organometallic Chemistry to Catalysis... 

Abstract The purpose of this chapter is to present a survey of the organometallic chemistry and catalysis of rhodium and iridium related to the oxidation of organic substrates that has been developed over the last 5 years, placing special emphasis on reactions or processes involving environmentally friendly oxidants. Iridium-based catalysts appear to be promising candidates for the oxidation of alcohols to aldehydes/ketones as products or as intermediates for heterocyclic compounds or domino reactions. Rhodium complexes seem to be more appropriate for the oxygenation of alkenes. In addition to catalytic allylic and benzylic oxidation of alkenes, recent advances in vinylic oxygenations have been focused on stoichiometric reactions. This review offers an overview of these reactions... 

Another chemical approach to the chemical conversion of methane involves organometallic reactions.85-89 Interesting work with iridium complexes and other transition metal insertion reactions (rhodium, osmium, rhenium, etc.) were carried out. Even iron organometallics were studied. These reactions take place in the coordination spheres of the metal complexes, but so far the reactions are stoichiometric and noncatalytic.77 In terms of synthetic hydrocarbon chemistry, these conversions are thus not yet practical, but eventually it is expected that catalytic reactions will be achieved. 

Hydride Complexes of the Transition Metals Iridium Organometallic Chemistry Luminescence Macrocyclic Ligands Rhodium Inorganic Coordination Chemistry. 

Results from studies on organoiridium compounds have made significant contributions in the area of catalysis. In some transformations, organometallic iridium compounds are the most active catalysts available. In others, where iridium may not yield the most active catalysts, iridium complexes nevertheless yield important information about the stmcture and reactivity of important catalytic intermediates. The following sections attempt to briefly cover some of the most important homogeneous catalytic process where iridium chemistry has had some impact. 

This review of some aspects of the organometallic chemistry of iridium is certainly not exhanstive. There have been some types of complexes that have receive little notice such as those containing polyolefmic hgands and related compounds. Also, there are other organic transformations that may be catalyzed by iridium complexes. However, throughout this chapter the reader has been directed to a number of primary references as well as a number of review articles that will delve into some areas of iridium organometallic chemistry more deeply. 

Reviews have appeared of the photophysics of molybdenum complexes, primary and secondary processes in organometallic chemistry, flash photolysis of Pe(CO)5 and Cr(CO)g, dinuclear manganese carbonyl compounds, the photochemistry of metal complexes isolated in low temperature matrices, cluster complexes, diene complexes, photoproduction of coordinativeiy unsaturated species containing rhodium or iridium, and redox chemiluminescence of organometallic compounds.Synthetic and metal organic photochemistry in industry has also been reviewed. 

The chemistry of metal-carbon triple bonds has developed considerably during the late 1980s. The synthetic basis was broadened, the utility of high-valent metal alkylidynes in metathesis reactions was further developed and refined, and the potential of low-valent carbyne complexes for applications in organic synthesis has become more apparent. The discovery of novel iridium alkylidyne complexes indicates that the full range of metal-carbon triple bonds is not yet known. We can therefore expect that future work in this area of organometallic chemistry will lead to new discoveries with fundamental implications and practical applications. 

Complex chemistry of cyclophanes links the two best examined two-layered molecules of organic and organometallic chemistry, namely [22 ]para-cyclophane and ferrocene. The rich redox chemistry of ruthenium, cobalt, rhodium and iridium therefore provides a basis for constructing polymeric structures, of which some oligomeric building units are already known. 

This group includes an important part of organometallic chemistry, that of arene, ferrocene and cymanthrene complexes and certain complexes of rhodium and iridium. In this case the chiral element is composed of the metal and the prochiral ligand. Figure 2.23 represents the two enantiomers of the 1,2-disubstituted ferrocene complex(2.15). ... 

An alternative route used in organometallic chemistry is the reaction of low valent organometallic derivatives with alkyl (aryl) halides. The two electron oxidative addition of alkyl (aryl) halides or cyclopropane derivatives to metalloporphyrins such as [M (Por)] leads to metal alkyl (aryl) o-bonded porphyrins of cobalt " rhodium and iridium ° (Scheme 2). Substitution of aryl and vinyl halides by electrochemically generated iron(I) porphyrins also leads to o-bonded Fe complexes ... 

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