Osmium carbonyl complexes

In the early work on the thermolysis of metal complexes for the synthesis of metal nanoparticles, the precursor carbonyl complex of transition metals, e.g., Co2(CO)8, in organic solvent functions as a metal source of nanoparticles and thermally decomposes in the presence of various polymers to afford polymer-protected metal nanoparticles under relatively mild conditions [1-3]. Particle sizes depend on the kind of polymers, ranging from 5 to >100 nm. The particle size distribution sometimes became wide. Other cobalt, iron [4], nickel [5], rhodium, iridium, rutheniuim, osmium, palladium, and platinum nanoparticles stabilized by polymers have been prepared by similar thermolysis procedures. Besides carbonyl complexes, palladium acetate, palladium acetylacetonate, and platinum acetylac-etonate were also used as a precursor complex in organic solvents like methyl-wo-butylketone [6-9]. These results proposed facile preparative method of metal nanoparticles. However, it may be considered that the size-regulated preparation of metal nanoparticles by thermolysis procedure should be conducted under the limited condition. 

The osmium-carbyne carbon bond lengths for the three complexes do not differ significantly, and reference to Table IV indicates that these distances are distinctly shorter than the characterized metal-carbon double bonds of osmium carbene and carbonyl complexes. In both osmium alkylidene and carbyne complexes, then, the metal-carbon multiple bond lengths are largely insensitive to changes in the metal electron density (cf. Section IV,B). 

Methylbenzene halogen complex of, 3 122 iodine monochloridecomplese, 3 109 Methylchlorosilanes hydrolysis, 42 149-150, 157 pyrolysis products of, 7 356-363 Methylcobalamin, 19 151, 152 Methyl-coenzyme M reductase, 32 323-325 EPR spectra, 32 323, 325 F43 and, 32 323-324 function, 32 324-325 Methyl-CoM reductase, 32 329 Methyl cyanide, osmium carbonyl complexes, reaction, 30 198-201 Methylcyclophosphazene salts, 21 70 synthesis, 21 109... 

It is also relevant to record that several iron-carbonyl complexes with bridging, and in one case terminal, aryltellurol ligands have been prepared by reaction of Fe(CO)5, Fe(CO)12 or [ji-CpFe(CO)2]2 with diaryl ditellurides and which, together with complexes containing other transition metal carbonyls, e.g, ruthenium, osmium and manganese, provide a substantial number of interesting compounds.2... 

Binding energy, pentacarbonyliron, 6, 3 Binuclear complexes bis-Cp titanium halides, 4, 522 with Ni-M and Ni-C cr-bonds heterometallic clusters, 8, 115 homometallic clusters, 8, 111 Binuclear dicarbonyl(cyclopentadienyl)hydridoiron complexes, with rand C5 ligands, 6, 178 Binuclear iridium hydrides, characteristics, 7, 410 Binuclear monoindenyl complexes, with Ti(IV), 4, 397 Binuclear nickel(I) carbonyl complexes, characteristics, 8, 13 Binuclear osmium compounds, with hydrocarbon bridges without M-M bonds, 6, 619... 

This article is intended to review the published work on the photochemistry and photophysics of osmium complexes that has appeared in the literature over the past several years. We have attempted to cover, albeit somewhat selectively, literature dating back to the year 2000. A variety of reviews pertaining to particular aspects of osmium photophysics and photochemistry were published prior to 2000. A few reviews discuss the photophysical behavior of primarily monometallic Os complexes in solution [1,2]. Several earlier reviews discuss light induced energy and electron transfer reactions involving osmium complexes in much of this work the Os complex is not the chro-mophore [3-6]. Finally, one review exists discussing the photochemistry of Os carbonyl complexes [7]. 

These early successes with carbonyl complexes of rhenium encouraged me to undertake systematic research on the carbon monoxide chemistry of the heavy transition metals at our Munich Institute during the period 1939-45, oriented towards purely scientific objectives. The ideas of W. Manchot, whereby in general only dicarbonyl halides of divalent platinum metals should exist, were soon proved inadequate. In addition to the compounds [Ru(CO)2X2] (70), we were able to prepare, especially from osmium, numerous di- and monohalide complexes with two to four molecules of CO per metal atom (29). From rhodium and iridium (28) we obtained the very stable rhodium(I) complexes [Rh(CO)2X]2, as well as the series Ir(CO)2X2, Ir(CO)3X, [Ir(CO)3]j (see Section VII,A). With this work the characterization of carbonyl halides of most of the transition metals, including those of the copper group, was completed. 

Osmium(n).—Group VII Donors. Hydrido- and halogeno-carbonyl complexes. Carbonylation of [OsHX(CO)(PCy3)2] has produced the novel dicarbonyl hydride [OsHX(CO)2(PCy3)2] (X = Cl or Br Cy = tricyclohexyl).17 I.r. and n.m.r. data indicate the geometry (17). Addition of other ligands to the five-co-ordinate... 

A binuclear bis(/z-germylene) osmium carbonyl complex [(OC)4Os(GeMe2)]2 on photolysis or thermolysis yields a mixture of an interesting series of (/z-germylene) osmium clusters36. Bis(metalcarbonyl)germacyclopentene complexes on photolysis or thermolysis... 

The wide area of osmium cluster carbonyl chemistry lies beyond the scope of this chapter (see refs. 15 and 16), though a few carbonyl complexes are covered, and of course there is full coverage of the cyanide chemistry of osmium. 

Octaethylporphyrin (OEP) affords three osmium nitrosyl complexes Os(NO)(OMe)(OEP), made from Os(CO)py(OEP), methanol and NO 232 with HF this yields Os(NO)F(OEP)232 and with HC104 it gives 0s(N0)(0C103)(0EP).2SS The nitrosyl carbonyl complex [Os(NO)(CO)Cl2(PPh3)2]BF4 is made by reaction of Os(NO)(CO)Cl(PPh3)2 with HBF4.223... 

Many transition metal carbonyl complexes have been prepared, often inadvertently, by allowing a metal halide or polyhalometallate to react with a ligand in an organic solvent with carbon-oxygen bonds. Indeed, carbonyl abstraction is an important synthetic route to tran5 -[MCl(CO)(PPh3)2] (M = Rh, Ir) or [OsHX(CO)(ZPh3)3] (X = Cl, Br Z = P, As) and related osmium(II) complexes. 

Carbonyl Complexes of the Transition Metals Mechanisms of Reaction of Organometallic Complexes Osmium Inorganic Coordination Chemistry Semiconductor Interfaces. 

---