Transition metal complexes osmium

Cundari et aZ. have used an effective core potential model to study the nonlinear optical properties of a transition metal complex, osmium tetroxide. 

Balzani et al. prepared dendrimers with metal complexes serving both as core [36] and as branching unit The metallodendrimer in Fig. 2.10 is constructed solely from polypyridine ligands and transition metal ions. Such dendritic transition metal complexes can be synthesised both convergently and divergently and different transition metal ions (ruthenium/osmium) can be incorporated. This provides a means of influencing the luminescence properties of the den-drimer. Thus the energy transfer process proceeds from the inside outwards in... 

ECL from inorganic chromophores has been observed from a variety of transition metal complexes of ruthenium, osmium, palladium, platinum, and a few other transition metal chromophores, some of which are listed in Tables 2 and 3. For example, ECL has been observed from tetrakis(pyrophosphito)diplatinate(II),... 

Abstract The applications of hybrid DFT/molecular mechanics (DFT/MM) methods to the study of reactions catalyzed by transition metal complexes are reviewed. Special attention is given to the processes that have been studied in more detail, such as olefin polymerization, rhodium hydrogenation of alkenes, osmium dihydroxylation of alkenes and hydroformylation by rhodium catalysts. DFT/MM methods are shown, by comparison with experiment and with full quantum mechanics calculations, to allow a reasonably accurate computational study of experimentally relevant problems which otherwise would be out of reach for theoretical chemistry. 

Different strategies have been used to attach transition metal complexes to proteins for example, the imidazole moiety of histidine can be coordinated to metal centres such as ruthenium(II), osmium(II) and rhenium(I). Many studies have utilised the imidazole of a histidine residue as a ligand for... 

There have been a number of reports of indirect coupling constants to carbon in organometallic compounds (see Tables XXXI and XXXII). Several trends are discernible. For transition metal complexes, the trends in V(i3C—M—3ip) and (i C—M— H) appear to follow those observed for V( P—M— H) and V( P—M— P). For complexes of ruthenium, osmium, rhodium, iridium, palladium, and platinum, it is generally found that V(A—M—B) (A, B = P, H) is large when... 

This has been the most frequently used method for the preparation of transition metal complexes with chromium, molybdenum, tungsten, maganese, iron, osmium, cobalt and nickel as the transition metal (equations 147, I48 149, 150 151, 152 153 , 154 and 155 ). 

A transformation showing enhancement of the reactivity of phenol through transition metal complexation occurs in the reaction of [Os(NH3)s(fi -phenol]-(OTO2 with maleic anhydride in acetonitrile over 20 hours at ambient temperature followed by recovery of the product, dimethyl (4-hydroxyphenyl)succinate in 85% yield by simple ethereal precipitation and removal of the osmium by refluxing in acidic methanol (ref.39). These last two examples illustrate the versatility of the appropriately modified phenolic structure to function either in a nucleophilic or in an electrophilic manner. 

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