Dissociation constants of some Schiff bases and stability constants of their copper, cobalt, nickel and zinc complexes

2007 ◽  
Vol 32 (6) ◽  
pp. 803-810 ◽  
Author(s):  
Mehmet Tunçel ◽  
Hayati Sarı
Keyword(s):  
Schiff Bases ◽  
Stability Constants ◽  
Dissociation Constants ◽  
Zinc Complexes ◽  
Cobalt Nickel

scholarly journals Metal-Based Biologically Active Compounds: Synthesis, Spectral, and Antimicrobial Studies of Cobalt, Nickel, Copper, and Zinc Complexes of Triazole-Derived Schiff Bases

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Kiran Singh ◽  
Yogender Kumar ◽  
Parvesh Puri ◽  
Chetan Sharma ◽  
Kamal Rai Aneja
Keyword(s):  
Metal Complexes ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Condensation Reaction ◽  
Zinc Complexes ◽  
Biologically Active ◽  
Planar Geometry ◽  
Cobalt Nickel ◽  
Copper And Zinc ◽  
Nickel Copper

A series of cobalt, nickel, copper, and zinc complexes of bidentate Schiff bases derived from the condensation reaction of 4-amino-5-mercapto-3-methyl/ethyl-1,2,4-triazole with 2,4-dichlorobenzaldehyde were synthesized and tested as antimicrobial agents. The synthesized Schiff bases and their metal complexes were characterized with the aid of elemental analyses, magnetic moment measurements, spectroscopic and thermogravimetric techniques. The presence of coordinated water in metal complexes was supported by infrared and thermal gravimetric studies. A square planar geometry was suggested for Cu(II) and octahedral geometry proposed for Co(II), Ni(II), and Zn(II) complexes. The Schiff bases and their metal complexes have been screened for antibacterial (Pseudomonas aeruginosa, Bacillus subtilis) and antifungal activities (Aspergillus niger, A. flavus). The metal complexes exhibited significantly enhanced antibacterial and antifungal activity as compared to their simple Schiff bases.

scholarly journals Antimicrobial, spectral and thermal studies of divalent cobalt, nickel, copper and zinc complexes with triazole Schiff bases

2017 ◽  
Vol 10 ◽  
pp. S978-S987 ◽  
Author(s):  
Kiran Singh ◽  
Yogender Kumar ◽  
Parvesh Puri ◽  
Chetan Sharma ◽  
Kamal Rai Aneja
Keyword(s):  
Schiff Bases ◽  
Thermal Studies ◽  
Zinc Complexes ◽  
Cobalt Nickel ◽  
Copper And Zinc ◽  
Nickel Copper ◽  
Divalent Cobalt

scholarly journals Synthesis of the Bacteriostatic Poly(L-Lactide) by Using Zinc (II)[(acac)(L)H2O] (L = Aminoacid-Based Chelate Ligands) as an Effective ROP Initiator

2021 ◽  
Vol 22 (13) ◽  
pp. 6950
Author(s):  
Renata Barczyńska-Felusiak ◽  
Małgorzata Pastusiak ◽  
Piotr Rychter ◽  
Bożena Kaczmarczyk ◽  
Michał Sobota ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Antibacterial Properties ◽  
Antimicrobial Effect ◽  
Zinc Complexes ◽  
Antibacterial And Antifungal Activities ◽  
Aspergillus Brasiliensis ◽  
Acetylacetonate Complex ◽  
Distorted Trigonal Bipyramid ◽  
Composition Structure ◽  
Antibacterial And Antifungal

The paper presents a synthesis of poly(l-lactide) with bacteriostatic properties. This polymer was obtained by ring-opening polymerization of the lactide initiated by selected low-toxic zinc complexes, Zn[(acac)(L)H2O], where L represents N-(pyridin-4-ylmethylene) tryptophan or N-(2-pyridin-4-ylethylidene) phenylalanine. These complexes were obtained by reaction of Zn[(acac)2 H2O] and Schiff bases, , the products of the condensation of amino acids and 4-pyridinecarboxaldehyde. The composition, structure, and geometry of the synthesized complexes were determined by NMR and FTIR spectroscopy, elemental analysis, and molecular modeling. Both complexes showed the geometry of a distorted trigonal bipyramid. The antibacterial and antifungal activities of both complexes were found to be much stronger than those of the primary Schiff bases. The present study showed a higher efficiency of polymerization when initiated by the obtained zinc complexes than when initiated by the zinc(II) acetylacetonate complex. The synthesized polylactide showed antibacterial properties, especially the product obtained by polymerization initiated by a zinc(II) complex with a ligand based on l-phenylalanine. The polylactide showed a particularly strong antimicrobial effect against Pseudomonas aeruginosa, Staphylococcus aureus, and Aspergillus brasiliensis. At the same time, this polymer does not exhibit fibroblast cytotoxicity.

Studies in the stereochemistry of zinc(II). VI. Zinc complexes with quadridentate Schiff bases

1967 ◽  
Vol 20 (5) ◽  
pp. 885 ◽  
Author(s):  
GE Batley ◽  
DP Graddon
Keyword(s):  
Schiff Bases ◽  
Infrared Spectra ◽  
Zinc Complexes ◽  
Steric Effects ◽  
Pyridine Solution ◽  
Carbon Chains ◽  
Tetrahedral Environment ◽  
Oxygen Atoms

Zinc complexes have been prepared with Schiff bases formed from salicylaldehyde and polymethylenediamines with chains of 2-9 carbon atoms. The anhydrous zinc complexes of ligands with 2-3 carbon chains readily form 1 : 1 adducts with water or bases such as pyridine; the ultraviolet and infrared spectra of these anhydrous compounds indicate that they are polymeric with bridging oxygen atoms, the zinc being 5-coordinate. The zinc complexes of ligands with carbon chains of four or more atoms do not form adducts, even in pyridine solution, and their spectra show that none of the oxygen atoms is bridging, the zinc being 4-coordinate. The stereochemistry of the zinc appears to be determined solely by steric effects: when the ligand is such that 4-coordination can produce a tetrahedral environment, further coordination does not occur; when 4-coordination cannot produce a tetrahedral environment, 5- coordination always occurs.

Pseudopolarographic determination of stability constants of labile zinc complexes in fresh water

1995 ◽  
Vol 310 (1) ◽  
pp. 131-138 ◽  
Author(s):  
M. Vega ◽  
R. Pardo ◽  
M.M. Herguedas ◽  
E. Barrado ◽  
Y. Castrillejo
Keyword(s):  
Fresh Water ◽  
Stability Constants ◽  
Zinc Complexes
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