20717-73-1Relevant articles and documents
H/D exchange, protolysis and oxidation of C3-C5 alkanes in HF-SbF5. σBasicity vs. reactivity of C-H bonds
Goeppert, Alain,Sommer, Jean
, p. 1335 - 1339 (2002)
The relative reactivity and basicity of CH bonds in C3-C5 alkanes was studied using the strongest deuterated superacid, DF-SbF5, at various concentrations of SbF5. In all cases, at concentrations up to approxima
Effect of a Hydrogen Pretreatment on the Mechanism of Deuterium Addition Exchange of Propene over Ni-Cu Alloy Catalysts
Naito, Shuichi,Tanimoto, Mitsutoshi
, p. 1253 - 1260 (2007/10/02)
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 before cooling (E-surface).For Cu-rich alloy catalysts, however, the E-surface exhibited a lower activity and a higher activation energy than did the D-surface.A comparison of the TPF spectra of adsorbed hydrogen with the dependence of the activity upon the evacuation temperature suggests that strongly adsorbed hydrogen retards the reaction over Ni and Ni-rich alloy catalysts at lower temperature.Microwave spectroscopic analysis demonstrated that the reaction intermediates over D- and E-surfaces of Cu-rich alloy catalysts were similar to those over Cu and Ni metals, respectively.This result suggests that a hydrogen pretreatment of Cu-rich alloys forms a specific surface structure which is destroyed by evacuation at elevated temperatures.
Reactions of Cyclopropane and Deuterium over Supported Metal Catalysts
Brown, Ronald,Kemball, Charles
, p. 3815 - 3822 (2007/10/02)
The reaction of cyclopropane and deuterium has been studied at low temperatures over a number of supported metal catalysts.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 substancially with the nature of the metal and provided information about the types of adsorbed intermediates involved in the mechanism of the reactions. The rection of propene and deuterium was also followed over supported platinum catalysts.In contrast to the results with cyclopropane, exchange of propene occured and the propanes formed from propene were markedly different from those from cyclopropane, reflecting differences in the mechanism of the reactions. Evidence of dual-function catalysis was obtained using alumina-supported iridium with cyclopropane and deuterium; exchange took place on the support and ring-opening on the metal.Similar dual functionality was observed for reactions of methylcylopropane or 1,1-dimethylcyclopropane with deuterium over the same Ir/Al2O3 catalyst.As a consequence of the present work, the high selectivity for the exchange of primary hydrogen atoms in various hydrocarbons over Ir/Al2O3 is now considered to be a function of the support rather than of the metal.
Reactions of FeCH2(+) and CoCH2(+) with Aliphatic Alkanes in the Gas Phase. Activation of C-H and C-C Bonds by Naked Transition-Metal Carbene Ions
Jacobson, D. B.,Freiser, B. S.
, p. 4373 - 4378 (2007/10/02)
Gas-phase reactions of the title carbenes with several aliphatic alkanes using Fourier transform mass spectrometry (FTMS) ,are described.CoCH2(+) reacts with alkanes larger than methane whereas FeCH2(+) reacts with alkanes larger than ethane.Both FeCH2(+) and CoCH2(+) react predominantly by initial C-H bond insertion with some C-C bond insertion also observed.As a consequence of facile carbene-alkyl coupling, C-C bond cleavage processes proceed predominantly with elimination of the original carbene incorporated into the departing alkane neutral.In addition a small amount of C-C bond formation product is also observed.Finally, a greater degree of H/D scrambling is observed for CoCD2(+) than for FeCD2(+).
