Parahydrogen-Induced Polarization Study of the Silica-Supported Vanadium Oxo Organometallic Catalyst
نویسندگان
چکیده
منابع مشابه
Transfer of Parahydrogen-Induced Polarization to 19F:
Introduction Parahydrogen-Induced Polarization (PHIP) leads to strong signal enhancement in H-NMR if unsaturated substrates are hydrogenated with parahydrogen (p-H2) applying an appropriate catalyst. As shown before, this polarization can be transferred to heteronuclei such as C. For imaging the lung, a F-hyperpolarized contrast agent should be available, if possible for inhalation. Normally, t...
متن کاملParahydrogen-induced polarization at zero magnetic field.
We use symmetry arguments and simple model systems to describe the conversion of the singlet state of parahydrogen into an oscillating sample magnetization at zero magnetic field. During an initial period of free evolution governed by the scalar-coupling Hamiltonian HJ, the singlet state is converted into scalar spin order involving spins throughout the molecule. A short dc pulse along the z ax...
متن کاملVanadium oxide supported on mesocellulous silica foams (MCF): An efficient and reusable catalyst for selective oxidation of sulfides
A green, efficient and selective approach for the oxidation of sulfides to sulfoxides and sulfones with UHP at room temperature is reported. The reaction is performed in the presence of vanadia catalyst supported on mesocellular silica foam (MCF) with a V content ranging from 2% to 10% as heterogeneous and reusable catalyst. The structural and textural characterization of this catalyst were don...
متن کاملDirect oxidation of benzene to phenol in liquid phase by H2O2 over vanadium catalyst supported on highly ordered nanoporous silica
Vanadium supported on highly ordered nanoporous silica (VOx-LUS-1) was synthesized and characterized by XRD, Nitrogen adsorption‑desorption isotherms and UV-visible spectrophotometer. Direct oxidation of benzene to phenol in liquid phase by H2O2 peroxide were examined by using various solvents (methanol, acetone, acetic acid, acetonitryl). The maximum yield (25%) and selectivity (73%) of the ph...
متن کاملPresence of surface vanadium peroxo-oxo umbrella structures in supported vanadium oxide catalysts: fact or fiction?
Recent debates over the active site structure of supported vanadia/silica catalysts have suggested the existence of a surface vanadium peroxo-oxo "umbrella" structure. This study definitively demonstrates with Raman and UV-vis spectroscopy that the surface vanadia peroxo-oxo umbrella-like structure is not present for both hydrated and dehydrated supported vanadia catalysts such as supported van...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Journal of Physical Chemistry C
سال: 2018
ISSN: 1932-7447,1932-7455
DOI: 10.1021/acs.jpcc.7b12069