Organometallic complexes, carbon supported

Keeping our target of homogeneous catalysis in mind, we adopted a broad definition of organometallic complexes and included compounds without metal-carbon bonds (e. g., metal-phosphine and metal-nitrosyl complexes) as far as they retain the structural and reactivity features of typical organometallic compounds. Recent developments, e. g., the substitution of phosphine by carbene ligands (cf Section 3.1.1.1), support the validity of this view. 

Serp et al. [39] prepared activated carbon-supported platinum catalysts by chemical vapor deposition of organometallic compounds. They contacted carbon rods with a gas mixture containing He, 3% H2, and a 10 molar ratio of [Pt(CH3)2(COD)] (COD ri" -l,5-cyclooctadiene) for 12 minutes at 383 K and 50 torr. They concluded that preoxidation of the carbon support with HNO3 was a very important factor in obtaining well-dispersed platinum particles, as the oxygen surface complexes acted as anchoring centers for the platinum precursor. 

CARBON-SUPPORTED ORGANOMETALLIC COMPLEXES IN THE POLYMERIZATION REACTION OE OLEFINS... 

There is now a growing literature of nickel organometallic complexes that contain carbon dioxide or related cumulene ligands that result from reactions with carbon monoxide. The first structurally characterized complex of carbon dioxide was the nickel complex Ni(G02)(PCy3)2 reported in 1975. A more recent study of this complex provides the complete assignments of the vibrational spectra and theoretical calculations of different isomers in support of a mechanism for CO2 fluxionality that involves end-on coordination. The tridentate pincer ligand 2,6-bis((diiso-propylphosphino)methyl)phenyl (PGP) has been used to form the square-planar Ni(ii) hydroxide complex Ni(OH)(PGP). The complex Ni(OH)(PCP) reacts with CO to give a binuclear /X-GO2 complex (Equation (2)). 

For PEM fuel cell CLs, catalysts can be classified into three groups based on the active component carbon-supported Pt carbon-supported Pt-based catalysts in which Pt is alloyed with or modified by other metals such as Cr (Wells et al., 2008), Cu (Mani et ah, 2008), Co (Qian et ah, 2008), and Ru (Denis et ah, 2008) and non-Pt-based catalysts such as nonnoble metal-based catalysts (Izhar et ah, 2009) and organometallic complexes (Charreteur et ah, 2008). 

Hydrogenations are usually carried out at low temperatures because the reaction is exothermic. Low temperature hydrogenations are also of great importance in the production of fine chemicals, where the reaction is often performed in the liquid phase, with carbon-supported platinum or palladium or with organometallic complexes as the catalyst. Materials that catalyze hydrogenation are also active in dehydrogenation, which becomes thermodynamically favored at higher tempera-... 

---