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

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...

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.

scholarly journals Synthesis and Antibacterial Studies of Novel Phosphorus Ligand 5-(2-diphenylphosphino) phenyl-1,2-dihydro-1,2,4-triazole-3-thione and its Metal Complexes with some Transition Metals

2010 ◽  
Vol 4 (2) ◽  
pp. 37-45
Author(s):  
Matheel D. Al-Sabti ◽  
Ahmed A. H. Al-Amiery ◽  
Thorria R. Marzoog ◽  
Yasmien K. Al-Majedy
Keyword(s):  
Metal Complexes ◽  
Free Ligand ◽  
Antimicrobial Properties ◽  
Cadmium Complex ◽  
Gram Positive Bacteria ◽  
Visible Spectra ◽  
Number Of Microorganisms ◽  
Ft Ir ◽  
The Stability

This study involves the chemical synthesis of the novel ligand 5-(2-diphenylphosphino) phenyl-1,2-dihydro-1,2,4-triazole-3-thione (DPDTT) by the reaction of 2-diphenylphosphino benzoic acid with absolute ethanol that yield ethyl 2-diphenylphosphino benzoate and by cyclization of this compound with thiosemicarbazide, DPDTT will be produced. The chelating complexes of this ligand with Cr(III), Co(II), Ni(II), Cu(II) and Cd(II) were also prepared and studied. The new complexes were characterized by FT-IR, UV/visible spectra, and room temperature magnetic susceptibility. The stability for the prepared complexes was also measured using the density function theory and it was found that the cadmium complex is the most stable and the chromium complex is the least stable. Free ligand and its metal complexes have been tested in vitro against a number of microorganisms, like gram positive bacteria Staphylococcus aureus and gram negative bacteria E. coli, Proteus vulgaris, Pseudomonas and Klebsiella in order to assess their antimicrobial properties. All complexes showed considerable activity against all the studied bacteria.

The stability of the metal complexes of cyclic tetra-aza tetra-acetic acids

Talanta ◽  
1992 ◽  
Vol 39 (3) ◽  
pp. 249-254 ◽  
Author(s):  
Silvia Chaves ◽  
Rita Delgado ◽  
J.J.R.Frausto Da Silva
Keyword(s):  
Metal Complexes ◽  
The Stability ◽  
Acetic Acids
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