scholarly journals Exploring the stability of the NHC‒metal bond using thiones as probes

2021 ◽  
Author(s):  
Nathalie Ségaud ◽  
Chloë Johnson ◽  
Albert Farre ◽  
Martin Albrecht
Keyword(s):  
Metal Complexes ◽  
Homogeneous Catalysis ◽  
Carbon Bond ◽  
Metal Bond ◽  
The Stability

The metal−carbon bond in N-heterocyclic carbene (NHC) metal complexes, which are ubiquitous in modern homogeneous catalysis, is often conjectured to be robust. Here, carbene dissociation was evaluated from a series...

ChemInform Abstract: KINETIC STUDIES ON REACTIONS OF METAL COMPLEXES. PART XVII. THE STABILITY OF THE BORAZOLE-TO-METAL BOND IN R3B3N3R′3CR(CO)3. KINETIC AND THERMOCHEMICAL STUDIES

1978 ◽  
Vol 9 (12) ◽  
Author(s):  
M. SCOTTI ◽  
H. WERNER ◽  
D. L. S. BROWN ◽  
S. CAVELL ◽  
J. A. CONNOR ◽  
...  
Keyword(s):  
Metal Complexes ◽  
Kinetic Studies ◽  
Metal Bond ◽  
The Stability

Density Functional Theory Studies on the Stability of Alkaline Metal Complexes of Pentazole and Oxopentazole Anions

2017 ◽  
Vol 38 (12) ◽  
pp. 1474-1480
Author(s):  
Insook Kang ◽  
Soo Gyeong Cho ◽  
Hai Whang Lee ◽  
Kiyull Yang
Keyword(s):  
Density Functional Theory ◽  
Metal Complexes ◽  
Density Functional ◽  
Alkaline Metal ◽  
Functional Theory ◽  
The Stability

scholarly journals Synthesis of Some 3d Metal Complexes of Quinine and their Toxicological Studies

1970 ◽  
Vol 25 ◽  
pp. 19-28 ◽  
Author(s):  
Adedibu C. Tella ◽  
Joshua A. Obaleya
Keyword(s):  
Stability Constant ◽  
Metal Complexes ◽  
Chemical Society ◽  
Cinchona Alkaloids ◽  
Albino Rats ◽  
Spectroscopic Techniques ◽  
Tetrahedral Geometry ◽  
Toxicological Studies ◽  
3D Metal Complexes ◽  
The Stability

Four metal complexes of antimalarials cinchona alkaloids; [Co(Quin)Cl3]-1,[Fe(Quin)Cl2H2O]SO3H2O-2, [Cu(Quin)ClSO4]∞-3 and [Cd(Quin)ClSO4]∞-4 have beensynthesized and characterized by elemental analysis, conductivity, magnetic moment, IR,UV-Vis and mass spectroscopic techniques. The tetrahedral geometry is assigned for all thefour complexes and the quinine ligand is protonated at quinuclidine N atom with thecoordination of the metal at quinoline N atom for all the complexes. Complexes 1 and 2have zwitterionic structures while complexes 3 and 4 are polymeric in nature with zig-zagextended chains (MCl- O -SO2- O -MCl- O –SO2---).Stability constant of the complexes were evaluated for the metal salts. The value of thestability constant (β) was found to be log 10.48, 9.92, 7.98 and 7.81 for Cu(II), Fe(III),Co(II) and Cd(II), respectively and the order of β was found to beCu(II)>Fe(III)>Co(II)>Cd(II). The stability constant data revealed that concomitantlyadministration of quinine with preparation containing these metals may reduce theirefficacy. Toxicological study was carried out by investigating the effect of administration ofthe complexes on alkaline phosphatase activity of kidney, liver and serum of Albino rats. Allthe examined four metal complexes were found to be non-toxic.Keywords: Quinine, stability constant, FTIR, MS, phosphates activity.DOI:  10.3126/jncs.v25i0.3280Journal of Nepal Chemical Society Volume 25, 2010 pp 19-28

scholarly journals Efficiency increase in combined electro-chemical grinding of hard alloys by diamond metal bonded disks

2017 ◽  
Vol 2 (2) ◽  
pp. 3-8
Author(s):  
Ольга Медведева ◽  
Olga Medvedeva ◽  
Александр Янюшкин ◽  
Aleksandr Yanyushkin ◽  
Павел Архипов ◽  
...  
Keyword(s):  
Theoretical Models ◽  
Capacity Factor ◽  
Hard Alloys ◽  
Metal Bond ◽  
Disc Cutting ◽  
Efficiency Increase ◽  
The Stability ◽  
Cutting Capacity ◽  
Diamond Disc

In the paper there are emphasized problems connected with the use of diamond metal bond abrasive discs at the processing of hard alloys. The reasons of cutting capacity decrease are pointed out which limit a wide-spread use of a diamond metal bond tool. It is established that for the achievement of a required productivity and quality of ready products is possible at the expense of the application of electro-chemical and electro-physical methods of stropping and also due to the improvement of abrasive disc designs. This work reports the investigations of a cutting capacity of diamond discs at the working of hard alloys by a combined method of electro-chemical grinding with simultaneous continuous stropping. As an output parameter there was accepted a cutting capacity factor of a diamond which was assesses according to the changes in effective working capacity. On the basis of the results of the experimental data processed there were obtained theoretical models of the dependence of the cutting capacity factor upon electric and mechanical constituents of the modes of combined electro-chemical grinding. A complex of investigations directed to the detection of efficient modes ensuring the stability of cutting capacity in diamond metal bond discs is carried out. It is experimentally confirmed that the application of the method of combined electro-chemical grinding with the simultaneous continuous disc stropping at working hard alloy materials allows increasing diamond disc cutting capacity by 15% in comparison with other methods of the diamond working of such materials.

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