Parahydrogen-induced polarization in alkyne hydrogenation catalyzed by Pd nanoparticles embedded in a supported ionic liquid phase.
نویسندگان
چکیده
Parahydrogen-induced polarization was observed in the gas phase heterogeneous hydrogenation of propyne catalyzed by Pd(0) nanoparticles embedded in an ionic liquid phase supported on activated carbon fibers (Pd(0)/SILP/ACF). The results were markedly different from those obtained with a reference catalyst, Pd(0)/ACF, demonstrating the important role of the ionic liquid.
منابع مشابه
Stereoselective iron-catalyzed alkyne hydrogenation in ionic liquids.
Iron(0) nanoparticles in ionic liquids (ILs) have been shown to catalyse the semi-hydrogenation of alkynes. In the presence of a nitrile-functionalised IL or acetonitrile, stereoselective formation of (Z)-alkenes was observed. The biphasic solvent system allowed facile separation and re-use of the catalyst.
متن کاملParahydrogen-induced polarization by pairwise replacement catalysis on Pt and Ir nanoparticles.
Pairwise and random addition processes are ordinarily indistinguishable in hydrogenation reactions. The distinction becomes important only when the fate of spin correlation matters, such as in parahydrogen-induced polarization (PHIP). Supported metal catalysts were not expected to yield PHIP signals given the rapid diffusion of H atoms on the catalyst surface and in view of the sequential stepw...
متن کاملAqueous Ligand-Stabilized Palladium Nanoparticle Catalysts for Parahydrogen-Induced 13C Hyperpolarization.
Parahydrogen-induced polarization (PHIP) is a method for enhancing NMR sensitivity. The pairwise addition of parahydrogen in aqueous media by heterogeneous catalysts can lead to applications in chemical and biological systems. Polarization enhancement can be transferred from 1H to 13C for longer lifetimes by using zero field cycling. In this work, water-dispersible N-acetylcysteine- and l-cyste...
متن کاملPairwise hydrogen addition in the selective semihydrogenation of alkynes on silica-supported Cu catalysts.
Mechanistic insight into the semihydrogenation of 1-butyne and 2-butyne on Cu nanoparticles supported on partially dehydroxylated silica (Cu/SiO2-700) was obtained using parahydrogen. Hydrogenation of 1-butyne over Cu/SiO2-700 yielded 1-butene with ≥97% selectivity. The surface modification of this catalyst with tricyclohexylphosphine (PCy3) increased the selectivity to 1-butene up to nearly 10...
متن کاملParahydrogen enhanced NMR reveals correlations in selective hydrogenation of triple bonds over supported Pt catalyst.
Parahydrogen induced polarization using heterogeneous catalysis can produce impurity-free hyperpolarized gases and liquids, but the comparatively low signal enhancements and limited scope of substrates that can be polarized pose significant challenges to this approach. This study explores the surface processes affecting the disposition of the bilinear spin order derived from parahydrogen in the...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Chemical communications
دوره 46 31 شماره
صفحات -
تاریخ انتشار 2010