Functionalized bimetallic

Remarkably, the hydrozirconation can be applied to functionalized alkenylzinc reagents bearing an ester, chloride, or cyano functionality (Scheme 7.37) [230], The functionalized bimetallic species 129c—e gave significantly lower yields (55—64%) but excellent stereoselectivities (>94% ( ) Scheme 7.39). Although the (E)/(Z) ratio was always reproducible,... 

Aluminium cast onto steel or cast iron is used to produce integral aluminium/steel drums and bimetallic pistons. Aluminium clad onto other metals by mechanical bonding is used in heat-exchanger systems subject to multiple atmospheres or environments. The clad products are also used for cooking utensils and functional press work. 

In the analysis of EXAFS data on bimetallic clusters, we consider two EXAFS functions, one for each component of the clusters (8,12-15.17). If the treatment is limited to contributions of near-est neighbor backscattering atoms, each of the functions will consist of two terms. For a bimetallic cluster composed of elements a and b, the EXAFS associated with element a is given by the expression ... 

Bonacic-Koutecky, V., Burda, J., Mitric, R., Ge, M., Zampella, G. and Fantucci, P. (2002) Density functional study of structural and electronic properties of bimetallic silver - gold clusters Comparison with pure gold and silver clusters./oumol of Chemical Physics, 117, 3120-3131. 

Recent Progress in Bimetallic Nanoparticles Their Preparation, Structures and Functions... 

Bimetallic nanoparticles show many interesting functions. The bimetallic nanoparticles are emerging catalysts... 

The synthesis of bimetallic nanoparticles is mainly divided into two methods, i.e., chemical and physical method, or bottom-up and top-down method. The chemical method involves (1) simultaneous or co-reduction, (2) successive or two-stepped reduction of two kinds of metal ions, and (3) self-organization of bimetallic nanoparticle by physically mixing two kinds of already-prepared monometallic nanoparticles with or without after-treatments. Bimetallic nanoparticle alloys are prepared usually by the simultaneous reduction while bimetallic nanoparticles with core/shell structures are prepared usually by the successive reduction. In the preparation of bimetallic nanoparticles, one of the most interesting aspects is a core/shell structure. The surface element plays an important role in the functions of metal nanoparticles like catal5dic and optical properties, but these properties can be tuned by addition of the second element which may be located on the surface or in the center of the particles adjacent to the surface element. So, we would like to use following marks to inscribe the bimetallic nanoparticles composed of metal 1, Mi and metal 2, M2. 

Figure 13. Normalized catalytic activity (in mmol H2 per mmol surface Pd per s) as a function of metal composition of PVP-stabilized Pd/Pt bimetallic nanoparticles. The normalization was determined by the number of Pd atoms on the surface of the nanoparticle, assuming that Pd atoms exist selectively on the surface. (Reprinted from Ref. [48], 1993, with permission from Royal Society of Chemistry.)...

Dienols with 2 equiv. of 1 gave the corresponding bimetallic alkoxide organozir-conocene complexes however, protolysis allowed recovery of the alcohol functionality (Scheme 8-29) [107]. Alcohols can also be easily converted to ethers. Alkyl, aryl, silyl [85,112,183, 210] and THP [17, 153, 211, 219] ethers are stable under hydrozirconation conditions side products were observed only with the trimethylsUyl group [220, 221]. 

When the rhodium-catalyzed reaction is performed under a high pressure of CO in the presence of phosphite ligands, aldehyde products (159) are formed by insertion of CO into the rhodium-alkyl bond followed by reductive elimination (Eq. 31) [90]. The bimetallic catalysts were immobilized as nanoparticles, giving the same products and functional group tolerance, with the advantage that the catalyst could be recovered and reused without loss of... 

Methylcyclopentane is a powerful probe molecule for the study of metal surfaces. The product distribution on platinum depends on the following factors particle size 491 reaction conditions 492-494 carbonaceous residues,492,493,495 and the extent of the interface between the metal and the support.492,493,495 The hydrogenolysis rate of methylcyclopentane depends on the hydrogen pressure.496,497 The rate exhibits a maximal value as a function of hydrogen pressure on EuroPt catalysts.498 The hydrogenolysis of methylcyclopentane has also been studied over Pt-Ru bimetallic catalysts.499... 

Sathish Kumar et al. [45] prepared bimetallic Au-Ru nanoparticles by the simultaneous reduction of both Au3+ and Ru3+ ions by ultrasound irradiation at three different molar ratios (Au3+ Ru3+ 1 1, 1 3 and 1 5) in 4 h in the presence of PEG. A significant change in the absorption as a function of sonication time was observed for Au-Ru bimetallic particles (Fig. 6.10), which indicated the... 

In this review, the potential uses of sonochemistry for the preparation of monometallic and bimetallic metal nanoparticles and metal-loaded semiconductor nanoparticles have been highlighted. While specific examples available in the literature were discussed, the sonochemical technique seems to offer a platform technique that could be used for synthesizing a variety of functional materials. Most of the studies to date deal with laboratory scale exploration , it would be ideal if the concepts are tested under large scale experimental conditions involving specific applications. The authors sincerely hope that the information provided in this review would prompt such experimental investigation in a new dimension. 

Initiators such as (306) initiate the ROP of CL to form telechelic triblock diols.478 Molecular weights approach theoretical values with polydispersities <1.3 and no significant level of transesterification was detected at up to 95% conversions. Alternative bimetallic samarium initiators have been used to synthesize aromatic, cumulene and amine/imine link-functionalized poly(lactones).479... 

The hot-feed rubber extruder is usually characterised by a relatively large screw depth and a relatively short L/D ratio of the barrel of 3 to 8 1 with the greatest number of machines having a ratio of 4 1. The barrel comprises usually a cast iron outer with either a traditional replaceable nitride liner, or, in the case of one manufacturer, of a single piece construction with an integral cast liner which has a surface hardness of Rockwell C60-62 and a hardness depth of 1.5 mm. The functional life for the bimetallic barrels is longer than for conventional nitride liner systems. 

Cleghorn LAT, Cooper IR, Fishwick CWG, Grigg R, MacLachlan WS, Rasparini M, Sridharan V (2003a) Three-component bimetallic (Pd/In) mediated cascade allylation of C=X functionality Part 1. Scope and class 1 examples with aldehydes and ketones. J Qrganomet Chem 687 483-493... 

An aromatic C-H functionalization involving the m-addition of benzene to internal alkynes is mediated by a bimetallic palladium complex in the presence of catalytic amounts of a borane. The mechanism of process remains to be clarified (Equation (77)).73... 

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