Spin Diffusion in 3He, Adsorbed Nanostructured Material MCM-41

2018 ◽  
Vol 44 (8) ◽  
pp. 755-758 ◽  
Author(s):  
A. P. Birchenko ◽  
N. P. Mikhin ◽  
E. Ya. Rudavskii ◽  
Ya. Yu. Fysun
Keyword(s):  
Spin Diffusion ◽  
Nanostructured Material ◽  
Mcm 41

scholarly journals Magnetically recoverable nanostructured Pd complex of dendrimeric type ligand on the MCM-41: Preparation, characterization and catalytic activity in the Heck reaction

2020 ◽  
Vol 43 (1) ◽  
pp. 184-199
Author(s):  
Mohammad Abdollahi-Alibeik ◽  
Najmeh Gharibpour ◽  
Zahra Ramazani
Keyword(s):  
Heck Reaction ◽  
Palladium Complex ◽  
Nanostructured Material ◽  
Magnetic Core ◽  
Aryl Halides ◽  
Heterogeneous Samples ◽  
Recoverable Catalyst ◽  
Ft Ir ◽  
Magnetically Recoverable Catalyst ◽  
Mcm 41

AbstractA palladium complex of a dendrimer type ligand of aminoethylacrylamide immobilized onto the mesoporous channels of MCM-41 with magnetic core was prepared and characterized using various techniques such as XRD, TEM, BET, FT-IR, TGA, and VSM. The prepared nanostructured material was found as a magnetically recoverable catalyst for Heck reaction of aryl halides and vinylic C–H. The catalyst is easily recoverable with an external magnet and is reusable with different leaching amounts depending to loading of Pd. A hot filtration test was also performed and gave evidence that Palladium in heterogeneous samples can dissolve and then redeposit on the surface of the support material.

Kinetic study of template removal of MCM-41 nanostructured material

2004 ◽  
Vol 75 (2) ◽  
pp. 693-698 ◽  
Author(s):  
M. J. B. Souza ◽  
A. O. S. Silva ◽  
J. M. F. B. Aquino ◽  
V. J. Fernandes Jr. ◽  
A. S. Araújo
Keyword(s):  
Kinetic Study ◽  
Nanostructured Material ◽  
Template Removal ◽  
Mcm 41

Solid-state NMR characterization of drug-model molecules encapsulated in MCM-41 silica

2009 ◽  
Vol 81 (8) ◽  
pp. 1345-1355 ◽  
Author(s):  
Thierry Azaïs ◽  
Geoffrey Hartmeyer ◽  
Sandrine Quignard ◽  
Guillaume Laurent ◽  
Corine Tourné-Péteilh ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Quantum Coherence ◽  
Spin Diffusion ◽  
Nuclear Overhauser Effect ◽  
Pulse Excitation ◽  
Multiple Quantum ◽  
Mobile Species ◽  
Nmr Characterization ◽  
Mcm 41

In this contribution, we present a solid-state NMR approach to characterize drug-model molecules as ibuprofen, benzoic acid and lauric acid, encapsulated in MCM-41 silica and submitted to strong confinement effects. In particular, we show that by a careful choice of the solid-state NMR sequences, it is possible to efficiently characterize these highly mobile molecules and their interactions with the pore surface. Thus, we demonstrate that 13C NMR spectroscopy is a powerful tool to characterize and even quantify entrapped and non-entrapped species by using either single-pulse excitation (SPE) or cross-polarization (CP). Whereas the standard {1H}-13C CP experiment is of poor efficiency for mobile species, we show that 13C signal-to-noise (S/N) ratio can be significantly improved through 1H-13C cross-relaxation (namely, nuclear Overhauser effect, nOe) by using a 1H power-gated technique. The long transversal relaxation times [T2(1H) up to 22 ms] observed allow the set-up of J-coupling based experiments such as 2D {1H}-13C heteronuclear multiple-quantum coherence (HMQC) in order to fully characterize the encapsulated molecules. Thus, we demonstrate that the use of sequences derived from solution-state NMR such as these two latter experiments is highly efficient to characterize highly mobile organic molecules trapped in mesopores. Finally, we show that 1H spin diffusion-based experiments can give useful informations on the proximities between trapped molecules and the silica surface.

Stimulated echo and diffusion processes in 3He adsorbed by MCM-41 nanostructured material

2019 ◽  
Vol 45 (12) ◽  
pp. 1237-1240
Author(s):  
A. P. Birchenko ◽  
N. P. Mikhin ◽  
E. Ya. Rudavsky ◽  
Ya. Yu. Sopelnyk
Keyword(s):  
Diffusion Processes ◽  
Nanostructured Material ◽  
Stimulated Echo ◽  
And Diffusion ◽  
Mcm 41

Nuclear magnetization of 3He adsorbed by the nanostructured material MCM-41

2018 ◽  
Vol 44 (5) ◽  
pp. 420-422 ◽  
Author(s):  
A. P. Birchenko ◽  
N. P. Mikhin ◽  
A. S. Neoneta ◽  
E. Ya. Rudavskii ◽  
Ya. Yu. Fysun
Keyword(s):  
Nanostructured Material ◽  
Nuclear Magnetization ◽  
Mcm 41

The design and catalytic performance of molybdenum active sites on an MCM-41 framework for the aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran

2019 ◽  
Vol 9 (3) ◽  
pp. 811-821 ◽  
Author(s):  
Zhao-Meng Wang ◽  
Li-Juan Liu ◽  
Bo Xiang ◽  
Yue Wang ◽  
Ya-Jing Lyu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Sites ◽  
Aerobic Oxidation ◽  
Catalytic Performance ◽  
Mcm 41

The catalytic activity decreases as –(SiO)3Mo(OH)(O) > –(SiO)2Mo(O)2 > –(O)4–MoO.

Benzene confined in MCM-41 below its melting point : A proton NMR study

2000 ◽  
Vol 10 (PR7) ◽  
pp. Pr7-99-Pr7-102 ◽  
Author(s):  
G. Dosseh ◽  
D. Morineau ◽  
C. Alba-Simionesco
Keyword(s):  
Melting Point ◽  
Proton Nmr ◽  
Nmr Study ◽  
Mcm 41

A neutron scattering investigation of the structural properties of glassforming m-toluidine confined in MCM-41

2000 ◽  
Vol 10 (PR7) ◽  
pp. Pr7-95-Pr7-98 ◽  
Author(s):  
D. Morineau ◽  
F. Casas ◽  
C. Alba-Simionesco ◽  
A. Grosman ◽  
M.-C. Bellissent-Funel ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Structural Properties ◽  
Mcm 41

Nuclear spin diffusion in a rare spin species

1982 ◽  
Vol 43 (7) ◽  
pp. 1049-1058 ◽  
Author(s):  
M. Goldman ◽  
J.F. Jacquinot
Keyword(s):  
Nuclear Spin ◽  
Spin Diffusion ◽  
Spin Species

Longitudinal electronic and nuclear spin diffusion in atomic hydrogen

1985 ◽  
Vol 46 (8) ◽  
pp. 1335-1344 ◽  
Author(s):  
J.P. Bouchaud ◽  
C. Lhuillier
Keyword(s):  
Nuclear Spin ◽  
Atomic Hydrogen ◽  
Spin Diffusion
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