Interlayer Structure and Dynamics of ClO4-Layered Double Hydroxides

2002 ◽  
Vol 14 (3) ◽  
pp. 1195-1200 ◽  
Author(s):  
Xiaoqiang Hou ◽  
R. James Kirkpatrick
Keyword(s):  
Layered Double Hydroxides ◽  
Structure And Dynamics ◽  
Interlayer Structure ◽  
Double Hydroxides

scholarly journals A molecular dynamics framework to explore the structure and dynamics of layered double hydroxides

2018 ◽  
Vol 163 ◽  
pp. 164-177 ◽  
Author(s):  
Germán Pérez-Sánchez ◽  
Tiago L.P. Galvão ◽  
João Tedim ◽  
José R.B. Gomes
Keyword(s):  
Molecular Dynamics ◽  
Layered Double Hydroxides ◽  
Structure And Dynamics ◽  
Double Hydroxides

scholarly journals Interlayer Structure of Bioactive Molecule, 2-Aminoethanesulfonate, Intercalated into Calcium-Containing Layered Double Hydroxides

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Tae-Hyun Kim ◽  
Hyoung Jun Kim ◽  
Jae-Min Oh
Keyword(s):  
Layered Double Hydroxides ◽  
Solid Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcium Cation ◽  
Particle Size And Morphology ◽  
Interlayer Structure ◽  
Diffraction Patterns ◽  
Size And Morphology ◽  
Double Hydroxides

We have successfully intercalated 2-aminoethanesulfonate, a well-known biomolecule taurine, into calcium-containing layered double hydroxides via optimized solid phase intercalation. According to X-ray diffraction patterns and infrared spectroscopy, it was revealed that the intercalated taurine molecules were each directly coordinated to other calcium cation and arranged in a zig-zag pattern. Scanning electron microscopy showed that the particle size and morphology of the LDHs were not affected by the solid phase intercalation, and the surface of intercalates was covered by organic moieties. From ninhydrin amine detection tests, we confirmed that most of the taurine molecules were well stabilized between the calcium-containing LDH layers.

Molecular Dynamics Simulation of Interlayer Structure and Hydration Properties of Glycine Intercalated Layered Double Hydroxides

2011 ◽  
pp. 242-250
Author(s):  
Guo-Xiang Pan ◽  
Feng Cao ◽  
Pei-Song Tang ◽  
Hai-Feng Chen ◽  
Zhe-Ming Ni ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bond ◽  
Layered Double Hydroxides ◽  
Interlayer Spacing ◽  
Dynamics Simulation ◽  
Water Molecules ◽  
Hydration Properties ◽  
Interlayer Structure ◽  
Double Hydroxides ◽  
Water Contents

Interlayer structure, hydrogen-bond, hydration and swelling properties of glycine intercalated layered double hydroxides (LDHs-Gly) were investigated with molecular dynamics (MD) methods. The results show that the interlayer spacing dc increases as hydration level increases. The computed hydration energies reach the most negative values at low water contents and change rapidly over the range 1 = NW = 6, and slowly and gradually approach the potential energy for bulk SPC water at NW > 6. But there are no local minima in the energy over the entire hydration range. This result suggests that LDHs-Gly tend to absorb water continuously in water-rich environments and enhance swelling to delaminate the hydroxide layers. The interlayers of LDHs-Gly exhibit complex hydrogen-bond network. With water content increasing, the glycine molecules progressively change their orientation from parallel to the layers to nearly perpendicular. Water molecules firstly form hydrogen-bond with M-OH layers at low water contents. While the hydroxide layers gradually get to saturation state at Nw > 3. And then water molecules continuously fill the interlayer to expand interlayer spacing.

Density Functional Theory Investigating Interlayer Structure and Ion-Exchange Properties of Mg/Al Layered Double Hydroxides

2011 ◽  
Vol 239-242 ◽  
pp. 2293-2296 ◽  
Author(s):  
Guo Xiang Pan ◽  
Feng Cao ◽  
Jin Tian Yang ◽  
Zhe Ming Ni ◽  
Pei Song Tang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Ion Exchange ◽  
Layered Double Hydroxides ◽  
Density Functional ◽  
Interlayer Spacing ◽  
Mulliken Charge ◽  
Functional Theory ◽  
Host Layer ◽  
Interlayer Structure ◽  
Double Hydroxides

The two-sheets model was proposed to investigate interlayer structure and properties of Mg/Al layered double hydroxides (LDHs) containing F-, Cl-, Br-, I- and OH- using density functional theory (DFT). The results show that four types of halogen anions in the interlayer of LDHs have the same configurations due to simple sphere structures of isolated anions. As the size of halide anions increasing, the interlayer spacing dc increase. Mulliken charge analysis illustrates that the host layers interact with the guest anions by the electrostatic interaction and hydrogen bonding, and the charge transfers from anions to layers. The frontier orbital of the host layer interacts with that of the guest anions, and the electron transfers from HOMO of anions to LUMO of the host layer. Moreover, the order in the absolute value of binding energy is: OH- >F- >Cl- >Br- >I-, that remains consistent with ion-exchange ability of LDHs reported.

Hydration, expansion, structure, and dynamics of layered double hydroxides

2003 ◽  
Vol 88 (1) ◽  
pp. 167-179 ◽  
Author(s):  
Xiaoqiang Hou ◽  
David L. Bish ◽  
Shan-Li Wang ◽  
Cliff T. Johnston ◽  
R. James Kirkpatrick
Keyword(s):  
Layered Double Hydroxides ◽  
Structure And Dynamics ◽  
Double Hydroxides

Acceptorless amine dehydrogenation and transamination using Pd-doped layered double hydroxides

2018 ◽  
Author(s):  
Diana Ainembabazi ◽  
Nan An ◽  
Jinesh Manayil ◽  
Kare Wilson ◽  
Adam Lee ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Oxidation States ◽  
Secondary Amines ◽  
Primary Amines ◽  
Acid Dissolution ◽  
Oxidative Amination ◽  
Strong Function ◽  
Excellent Activity ◽  
High Yields ◽  
Double Hydroxides

<div> <p>The synthesis, characterization, and activity of Pd-doped layered double hydroxides (Pd-LDHs) for for acceptorless amine dehydrogenation is reported. These multifunctional catalysts comprise Brønsted basic and Lewis acidic surface sites that stabilize Pd species in 0, 2+, and 4+ oxidation states. Pd speciation and corresponding cataytic performance is a strong function of metal loading. Excellent activity is observed for the oxidative transamination of primary amines and acceptorless dehydrogenation of secondary amines to secondary imines using a low Pd loading (0.5 mol%), without the need for oxidants. N-heterocycles, such as indoline, 1,2,3,4-tetrahydroquinoline, and piperidine, are dehydrogenated to the corresponding aromatics with high yields. The relative yields of secondary imines are proportional to the calculated free energy of reaction, while yields for oxidative amination correlate with the electrophilicity of primary imine intermediates. Reversible amine dehydrogenation and imine hydrogenation determine the relative imine:amine selectivity. Poisoning tests evidence that Pd-LDHs operate heterogeneously, with negligible metal leaching; catalysts can be regenerated by acid dissolution and re-precipitation.</p> </div> <br>

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