نتایج جستجو برای: pt
تعداد نتایج: 46502 فیلتر نتایج به سال:
100 patients (93 females and 7 males) in ages ranging between 23 and 65 years were subjected to laparoscopic cholecystectomy for biliary colic (92 pts), acute cholecystitis (7 pts) or asymptomatic gallstones (1 pt). None had a history of icterus and in every case choledocholithiasis was excluded by means of serum alkaline phosphatase assessment and sonography (In addition to ERCP in 3 pts). 3 o...
The transition-metal-catalyzed denitrogenative transannulation of pyridotriazoles represents an efficient method for the synthesis of fused nitrogen-containing heterocycles. This method is based on the ability of pyridotriazole to exist in an equilibrium with diazo-form A, which can be trapped with Rh(II) to form the reactive pyridyl carbene intermediate B, capable of reacting with terminal alk...
An efficient synthetic approach that enables not only the control of Pt nanocubes but also the one-pot fabrication of novel Pt nanocube assemblies was developed for the first time. The integration of well-defined building blocks and unique superstructures endows Pt nanocube assemblies with enhanced performance in the methanol electrooxidation, showing a new concept for further enhancing the per...
The adsorption of atomic nitrogen on Ni/Pt(111) surface bimetallics has been investigated as a function of the local microstructure of Ni and Pt atoms via density functional theory (DFT) calculations. Microstructures include surface and subsurface Ni atoms on Pt(111) as limiting cases, and also small clusters of Ni in the first and/or second layer of Pt. It is shown that the binding energy of N...
A new class of benzimidazolylidene carbene-Pt(0) complexes was developed and used to efficiently catalyse the hydrosilylation of alkenes.
gem-Selective cross-dimerization and trimerization of silylacetylenes with alkynes via C-H activation using a rhodium(I)-pyridine-Nheterocyclic carbene catalyst have been developed. This protocol is applicable to variety of aliphatic or aromatic terminal alkynes, internal alkynes and gem-1,3-disubsituted enynes to afford the corresponding enynes and dienynes with high regioand stereoselectiviti...
195pt and 1h nmr has been used to show that addition of chlorine and bromine to [pt(cn)4]2_ in presence of perchloric acid in water results in cyanide and water scrambling with formation of eleven complexes of the type [pt(cn)4-ncl(h2o)n+1](n-1)+ (n=0, 1, 2, 3, 4). addition of nbu4oh to this solution gives (nbu4)2[pt(cn)4cl(oh)]. nmr measurements in acetone also show cyanide and hydroxyl group ...
The effect of different N-N spectator ligands on the reactivity of platinum(II) complexes was investigated by studying the water lability of [Pt(diaminocyclohexane)(H2O)2]2+ (Pt(dach)), [Pt(ethylenediamine)(H2O)2]2+ (Pt(en)), [Pt(aminomethylpyridine)(H2O)2]2+ (Pt(amp)), and [Pt(N,N'-bipyridine)(H2O)2]2+ (Pt(bpy)). Some of the selected N-N chelates form part of the coordination sphere of Pt(II) ...
A container used in contact lens cleaning requires a Pt plating weight of 1.5 mg for H₂O₂ decomposition although Pt is an expensive material. Techniques that decrease the amount of Pt are therefore needed. In this study, Pt nanoparticles instead of Pt plating film were supported on a substrate of acrylonitrile-butadiene-styrene copolymer (ABS). This was achieved by the reduction of Pt ions in a...
We have investigated the segregation of Pt atoms to the surfaces of Pt-Re nanoparticles using the Monte Carlo method and modified embedded-atom method potentials that we have developed for Pt-Re alloys. The Pt(75)Re(25) nanoparticles (containing from 586 to 4,033 atoms) are assumed to have disordered fcc configurations and cubo-octahedral shapes (terminated by [111] and [100] facets), while the...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید