Effect of a Hydrogen Pretreatment on the Mechanism of Deuterium Addition and Exchange of Propene over Ni–Cu Alloy Catalysts
作者:Shuichi Naito、Mitsutoshi Tanimoto
DOI:10.1246/bcsj.64.1253
日期:1991.4
The effects of a hydrogen pretreatment on the activity and reaction intermediate in a C3H6–D2 reaction over a Ni–Cu alloy as well as Ni metal catalysts were investigated in detail by applying an isotope tracer technique. Ni metal and Ni-rich alloy catalysts, cooled down to the reaction temperature under a hydrogen atmosphere (D-surface), exhibited low activity compared to that of a surface evacuated
通过应用同位素示踪技术详细研究了氢预处理对 Ni-Cu 合金和 Ni 金属催化剂上 C3H6-D2 反应的活性和反应中间体的影响。与冷却前抽真空的表面(E 表面)相比,在氢气氛下(D 表面)冷却至反应温度的 Ni 金属和富 Ni 合金催化剂表现出较低的活性。然而,对于富铜合金催化剂,E 表面比 D 表面表现出较低的活性和较高的活化能。吸附氢的 TPD 光谱与活性对抽真空温度的依赖性的比较表明,强烈吸附的氢在较低温度下会延迟 Ni 和富 Ni 合金催化剂的反应。微波光谱分析表明,富铜合金催化剂的 D 和 E 表面上的反应中间体分别与 Cu 和 Ni 金属上的反应中间体相似。这一结果表明,一...
Reactions of cyclopropane and deuterium over supported metal catalysts
作者:Ronald Brown、Charles Kemball
DOI:10.1039/ft9908603815
日期:——
The reaction of cyclopropane and deuterium has been studied at low temperatures over a number of supported metalcatalysts. The main reaction was normally ring-opening, yielding a mixture of isotopic propanes which were analysed mass-spectrometrically and by deuterium NMR spectroscopy. The patterns of isotopic propanes varied substantially with the nature of the metal and provided information about
H/D exchange, protolysis and oxidation of C<sub>3</sub>–C<sub>5</sub>alkanes in HF–SbF<sub>5</sub>. σ-Basicity vs. reactivity of C–H bonds
作者:Alain Goeppert、Jean Sommer
DOI:10.1039/b201437h
日期:——
exchange follows the Olah σ-basicity concept: tertiary>secondary>primary C–H bonds independently of the further reactivity of these bonds. At higher concentrations of SbF5 the exchange process gives way to increasing ionization of the alkane, first via protolysis and later via an oxidative process with concomitant reduction of SbF5.
Unprecedented double nucleophilic addition of a hydride at a central carbon of an η<sup>3</sup>-allyl ligand
作者:Makoto Minato、Ryoko Sekimizu、Daisuke Uchida、Takashi Ito
DOI:10.1039/b407976k
日期:——
the HSAB principle. The studies showed that the formation of propane can be explained by 1,2-hydrogen migration from the central to the terminal carbon of the allyl ligand, and the subsequent double nucleophilic addition of the hydride at the central carbon.
Reactions of the iron and cobalt carbenes FeCH2+ and CoCH2+ with aliphatic alkanes in the gas phase. Activation of carbon-hydrogen and carbon-carbon bonds by naked transition-metal carbene ions