scholarly journals Superconductivity and cobalt oxidation state in metastableNaxCoO2−δ∙yH2O(x≈1∕3;y≈4x)

2005 ◽  
Vol 72 (13) ◽  
Author(s):  
P. Barnes ◽  
M. Avdeev ◽  
J. Jorgensen ◽  
D. Hinks ◽  
H. Claus ◽  
...  
Keyword(s):  
Oxidation State ◽  
Cobalt Oxidation

Influences of interlayer distance and cobalt oxidation state on superconductivity of NaxCoO2

2004 ◽  
Vol 412-414 ◽  
pp. 14-20 ◽  
Author(s):  
Kazunori Takada ◽  
Hiroya Sakurai ◽  
Eiji Takayama-Muromachi ◽  
Fujio Izumi ◽  
Ruben A. Dilanian ◽  
...  
Keyword(s):  
Oxidation State ◽  
Interlayer Distance ◽  
Cobalt Oxidation

Methanol Decomposition on Co(0001): Influence of the Cobalt Oxidation State on Reactivity

2019 ◽  
Vol 123 (14) ◽  
pp. 9139-9145 ◽  
Author(s):  
Jun Chen ◽  
Qing Guo ◽  
Jiawei Wu ◽  
Wenshao Yang ◽  
Dongxu Dai ◽  
...  
Keyword(s):  
Oxidation State ◽  
Methanol Decomposition ◽  
Cobalt Oxidation

Nickel and Cobalt Oxidation State Evolution at Ni-Rich NMC Cathode Surfaces during Treatment

2020 ◽  
Vol 124 (30) ◽  
pp. 16508-16514
Author(s):  
James L. White ◽  
Forrest S. Gittleson ◽  
Mark Homer ◽  
Farid El Gabaly
Keyword(s):  
Oxidation State ◽  
State Evolution ◽  
Cobalt Oxidation

scholarly journals Methanol oxidation over model cobalt catalysts: Influence of the cobalt oxidation state on the reactivity

2010 ◽  
Vol 269 (2) ◽  
pp. 309-317 ◽  
Author(s):  
S. Zafeiratos ◽  
T. Dintzer ◽  
D. Teschner ◽  
R. Blume ◽  
M. Hävecker ◽  
...  
Keyword(s):  
Oxidation State ◽  
Methanol Oxidation ◽  
Cobalt Catalysts ◽  
Cobalt Oxidation

Chromium oxidation state mapping in human cells

2003 ◽  
Vol 104 ◽  
pp. 289-292 ◽  
Author(s):  
R. Ortega ◽  
B. Fayard ◽  
M. Salomé ◽  
G. Devès ◽  
J. Susini
Keyword(s):  
Oxidation State ◽  
Human Cells ◽  
Chromium Oxidation

A Short Synthesis of (+)-Brefeldin C via Enantioselective Radical Hydroalkynylation

2019 ◽  
Author(s):  
Lars Gnägi ◽  
Severin Vital Martz ◽  
Daniel Meyer ◽  
Robin Marc Schärer ◽  
Philippe Renaud
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Oxidation State ◽  
Single Step ◽  
Radical Process ◽  
Target Molecule ◽  
Short Synthesis ◽  
The One

<div><div><div><div><p>A very concise total synthesis of (+)-brefeldin C starting from 2-furanylcyclopentene is described. This approach is based on an unprecedented enantioselective radical hydroalkynylation process to introduce the two cyclopentane stereocenters in a single step. The use of a furan substituent allows to achieve a high trans diastereoselectivity during the radical process and it contains the four carbon atoms C1–C4 of the natural product in an oxidation state closely related to the one of the target molecule. The eight-step synthesis require six product purifications and it provides (+)-brefeldin C in 18% overall yield.</p></div></div></div></div>

Piperazine as an Inexpensive and Efficient Ligand for Pd-Catalyzed Homocoupling Reactions to Synthesize Bipyridines and Their Analogues

2019 ◽  
Vol 16 (1) ◽  
pp. 173-180
Author(s):  
Mingwei Chen ◽  
Jinyu Hu ◽  
Xiaoli Tang ◽  
Qiming Zhu
Keyword(s):  
Transition Metal ◽  
Oxidation State ◽  
Coupling Reaction ◽  
Aryl Halides ◽  
Metal Species ◽  
Good Substrate ◽  
Active Metal ◽  
Homocoupling Reaction ◽  
Catalytic Cycles ◽  
Reductive Homocoupling

Aim and Objective: The synthesis of bipyridines, especially 2, 2’-bipyridines, remains challenging because the catalytic cycle can be inhibited due to coordination of bipyridine to transition metal. Thus, the development of efficient methods for the synthesis of bipyridines is highly desirable. In the present work, we presented a promising approach for preparation of bipyridines via a Pd-catalyzed reductive homocoupling reaction with simple piperazine as a ligand. Materials and Methods: Simple and inexpensive piperazine was used as a ligand for Pd-catalyzed homocoupling reaction. The combination of Pd(OAc)2 and piperazine in dimethylformamide (DMF) was observed to form an excellent catalyst and efficiently catalyzed the homocoupling of azaarenyl halides, in which DMF was used as the solvent without excess reductants although stoichiometric reductant was generally required to generate the low-oxidation-state active metal species in the catalytic cycles. </P><P> Results: In this case, good to excellent yields of bipyridines and their (hetero) aromatic analogues were obtained in the presence of 2.5 mol% of Pd(OAc)2 and 5 mol% of piperazine, using K3PO4 as a base in DMF at 140°C. Conclusion: According to the results, piperazine as an inexpensive and efficient ligand was used in the Pd(OAc)2-catalyzed homocoupling reaction of heteroaryl and aryl halides. The coupling reaction was operationally simple and displayed good substrate compatibility.

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