Metal Complexes of 6-Hydroxymethylpyridine-2-carboxylic Acid

Spectrophotometric and pH-titration methods have been used to determine the stability constants at 25 �C of complexes between transition metal ions and the anion of 6-hydroxymethylpyridine-2-carboxylic acid. This anion is found to be a weaker base and a weaker complexing agent than the pyridine-2-carboxylate ion. There is some evidence for steric hindrance of tris complexes.

Download Full-text

Stability constants and spectral studies of complexes of 2-hydroxy-5-methylazobenzene-2′-carboxylic acid with some divalent metal ions

Canadian Journal of Chemistry ◽

10.1139/v84-391 ◽

1984 ◽

Vol 62 (11) ◽

pp. 2299-2301

Author(s):

C. Mahalingam ◽

J. K. Sthapak ◽

D. D. Sharma ◽

R. L. Tiwari ◽

Smita Sthapak

Keyword(s):

Carboxylic Acid ◽

Metal Ions ◽

Metal Complexes ◽

Stability Constants ◽

Divalent Metal ◽

Reflectance Spectra ◽

Spectral Studies ◽

Divalent Metal Ions ◽

The Stability

The stability constants of metal complexes of 2-hydroxy-5-methylazobenzene-2′-carboxylic acid have been determined spectrophotometrically. These follow the Irving–Williams sequence: log KOH(H) = 10.67, log K1(Co) = 9.02, log K1(Ni) = 9.68, log K1(Cu) = 13.37, log K1(Zn) = 7.58, and [Formula: see text]The chelates of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), and [Formula: see text] with the dye have been prepared and characterized on the basis of their ir and reflectance spectra.

Download Full-text

Potentiometric and thermodynamic studies of 3-methyl-1-phenyl-{p-[N-(pyrimidin-2-yl)-sulfamoyl]phenylazo}-2-pyrazolin-5-one and its metal complexes

Chemical Papers ◽

10.2478/s11696-006-0002-3 ◽

2006 ◽

Vol 60 (1) ◽

Cited By ~ 2

Author(s):

A. Fouda ◽

A. Al-Sarawy ◽

E. El-Katori

Keyword(s):

Transition Metal ◽

Metal Complexes ◽

Stability Constants ◽

Dissociation Constants ◽

Transition Metal Ions ◽

Effect Of Temperature ◽

Water Mixture ◽

Dissociation Process ◽

The Stability ◽

Metal Ligand

AbstractThe dissociation constants of 3-methyl-1-phenyl-{p-[N-(pyrimidin-2-yl)sulfamoyl]phenylazo}-2-pyrazolin-5-one and metal-ligand stability constants of its complexes with some transition metal ions have been determined potentiometrically in 0.1 M-KCl and ethanol—water mixture (30 vol. %). The order of the stability constants of the formed complexes increases in the sequence Mn2+, Co2+, Ni2+, Cu2+, La3+, Hf3+, UO22+, Zr4+. The effect of temperature was studied and the corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) were derived and discussed. The dissociation process is nonspontaneous, endothermic, and entropically unfavourable. The formation of the metal complexes was found to be spontaneous, exothermic, and entropically favourable.

Download Full-text

Composition and stability of some bivalent transition metal complexes of 3,5-dinitrosalicylic acid

Canadian Journal of Chemistry ◽

10.1139/v70-165 ◽

1970 ◽

Vol 48 (6) ◽

pp. 1007-1010 ◽

Cited By ~ 4

Author(s):

S. S. Dube ◽

S. S. Dhindsa

Keyword(s):

Transition Metal ◽

Comparative Study ◽

Metal Ions ◽

Metal Complexes ◽

Stability Constants ◽

Transition Metal Complexes ◽

Bivalent Metal ◽

Bivalent Metal Ions ◽

The Stability ◽

Bivalent Transition Metal

The interaction of Zn2+, Mn2+, Hg2+, and Cd2+ ions with 3,5-dinitrosalicylic acid was investigated by potentiometric titrations in aqueous 0.1 M KNO3 medium. In all cases the formation of 1:1 complex was indicated. The stability constants in the pH ranges 4.5–8.0, 4.5–8.0, 5.0–8.0, and 5.5–8.0 were determined by applying the Calvin and Melchior's extension of Bjerrum's method and the log K values were found to be 3.70, 2.95, 3.20, and 2.85, respectively. A comparative study of the complexes of 3,5-dinitrosalicylic acid with other bivalent metal ions has also been incorporated. The stability constants of the transition metal complexes obey the order Cu > Ni > Co > Zn > Mn, in agreement with Irving and William's rule.

Download Full-text

Synthesis, Characterization and in vitro Biological Evaluation of a New Schiff Base Derived from Drug and its Complexes with Transition Metal Ions

Revista de Chimie ◽

10.37358/rc.18.7.6393 ◽

2018 ◽

Vol 69 (7) ◽

pp. 1678-1681

Author(s):

Amina Mumtaz ◽

Tariq Mahmud ◽

M. R. J. Elsegood ◽

G. W. Weaver

Keyword(s):

Schiff Base ◽

Transition Metal ◽

Metal Ions ◽

Metal Complexes ◽

Transition Metal Complexes ◽

Free Ligand ◽

Transition Metal Ions ◽

Biological Evaluation ◽

Pyridoxal Hydrochloride

New series of copper (II), cobalt (II), zinc (II), nickel (II), manganese (II), iron (II) complexes of a novel Schiff base were prepared by the condensation of sulphadizine and pyridoxal hydrochloride. The ligand and metal complexes were characterized by utilizing different instrumental procedures like microanalysis, thermogravimetric examination and spectroscopy. The integrated ligand and transition metal complexes were screened against various bacteria and fungus. The studies demonstrated the enhanced activity of metal complexes against reported microbes when compared with free ligand.

Download Full-text