DFT Studies on the Methane Elimination Reaction of a Trinuclear Rare-Earth Polymethyl Complex: σ-Bond Metathesis Assisted by Cooperation of Multimetal Sites

2014 ◽  
Vol 33 (5) ◽  
pp. 1126-1134 ◽  
Author(s):  
Gen Luo ◽  
Yi Luo ◽  
Wenxiong Zhang ◽  
Jingping Qu ◽  
Zhaomin Hou
Keyword(s):  
Rare Earth ◽  
Dft Studies ◽  
Elimination Reaction ◽  
Methane Elimination

Synthesis of Rare Earth Catalyst LLa[N(TMS)2]•DME(L=3,5-But2-2-HO-C6H2CH-NH-C5H4N) and Catalytic Behavior for Polymerization of Rac-Lactide

2012 ◽  
Vol 184-185 ◽  
pp. 1302-1306
Author(s):  
Xi Zhu ◽  
Yao Rong Wang
Keyword(s):  
Rare Earth ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Molar Ratio ◽  
Elimination Reaction ◽  
Catalytic Behavior ◽  
Rare Earth Catalyst

A dianionic phenoxyamido ligand was the first to be used to stabilize organo-rare-earth mental amido complex. Amine elimination reaction of La[N(SiMe3)2]3(THF)2 with 3,5-But2-2-HO-C6H2CH-NH-C5H4N in a 1 : 1 molar-ratio gave the anionic phenoxyamido neodymium amide LLa[N(TMS)2]•DME (1) in a high isolated yield. Furthemore, the catalytic behavior of complex 1 for the ring-opening polymerization of rac-lactide was explored.

scholarly journals DFT Studies on cis-1,4-Polymerization of Dienes Catalyzed by a Cationic Rare-Earth Metal Complex Bearing an Ancillary PNP Ligand

Polymers ◽  
2017 ◽  
Vol 9 (12) ◽  
pp. 53 ◽  
Author(s):  
Xingbao Wang ◽  
Xiaohui Kang ◽  
Guangli Zhou ◽  
Jingping Qu ◽  
Zhaomin Hou ◽  
...  
Keyword(s):  
Rare Earth ◽  
Metal Complex ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Dft Studies ◽  
Rare Earth Metal Complex

Self-assembly of 1D coordination polymers of two rare-earth complexes with carboxylate linkages: Synthesis, crystal structure and DFT studies

Polyhedron ◽  
2011 ◽  
Vol 30 (13) ◽  
pp. 2195-2202 ◽  
Author(s):  
Dipak K. Hazra ◽  
Rupam Sen ◽  
Subratanath Koner ◽  
Madeleine Helliwell ◽  
Monika Mukherjee
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Coordination Polymers ◽  
Self Assembly ◽  
Rare Earth Complexes ◽  
Dft Studies

scholarly journals Rationalizing the Reactivity of Mixed Allyl Rare-Earth Borohydride Complexes with DFT Studies

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 820
Author(s):  
Sami Fadlallah ◽  
Jashvini Jothieswaran ◽  
Iker Del Rosal ◽  
Laurent Maron ◽  
Fanny Bonnet ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Rare Earth ◽  
Ring Opening ◽  
Density Functional ◽  
Ring Opening Polymerization ◽  
Polymerization Reaction ◽  
Experimental Investigations ◽  
Dft Studies ◽  
Functional Theory ◽  
Activation Barriers

The reactivity of rare-earth complexes RE(BH4)2(C3H5)(THF)x (RE = La, Nd, Sm, Y, Sc) toward the Ring-Opening Polymerization (ROP) of ε-caprolactone (ε-CL) was rationalized by Density Functional Theory (DFT) calculations. Even if the polymerization reaction can be initiated by both RE-(BH4) and RE-allyl bonds, experimental investigations have shown that the initiation via the borohydride ligand was favored, as no allyl group could be detected at the chain-end of the resulting polymers. DFT studies could confirm these observations, as it was highlighted that even if the activation barriers are both accessible, the allyl group is not active for the ROP of ε-CL due to the formation of a highly stable intermediate that disfavors the subsequent ring-opening.

Neutral ligand induced methane elimination from rare-earth metal tetramethylaluminates up to the six-coordinate carbide state

2009 ◽  
pp. 5755 ◽  
Author(s):  
Ajay Venugopal ◽  
Ina Kamps ◽  
Daniel Bojer ◽  
Raphael J. F. Berger ◽  
Andreas Mix ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Neutral Ligand ◽  
Methane Elimination

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Study of segregation in La1.8Sr0.2CuO4 superconductor by STEM-EDS microanalysis

1987 ◽  
Vol 45 ◽  
pp. 54-55
Author(s):  
T. F. Kelly ◽  
P. J. Lee ◽  
E. E. Hellstrom ◽  
D. C. Larbalestier
Keyword(s):  
Rare Earth ◽  
High Field ◽  
Transport Current ◽  
Total Thickness ◽  
New Class ◽  
Ceramic Superconductors ◽  
Current Densities ◽  
Group Ii ◽  
Eds Microanalysis

Recently there has been much excitement over a new class of high Tc (>30 K) ceramic superconductors of the form A1-xBxCuO4-x, where A is a rare earth and B is from Group II. Unfortunately these materials have only been able to support small transport current densities 1-10 A/cm2. It is very desirable to increase these values by 2 to 3 orders of magnitude for useful high field applications. The reason for these small transport currents is as yet unknown. Evidence has, however, been presented for superconducting clusters on a 50-100 nm scale and on a 1-3 μm scale. We therefore planned a detailed TEM and STEM microanalysis study in order to see whether any evidence for the clusters could be seen.A La1.8Sr0.2Cu04 pellet was cut into 1 mm thick slices from which 3 mm discs were cut. The discs were subsequently mechanically ground to 100 μm total thickness and dimpled to 20 μm thickness at the center.

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