 |
Potentiometric and thermodynamic studies of 3-methyl-1-phenyl-{ p -[ N -(pyrimidin-2-yl)-sulfamoyl]phenylazo}-2-pyrazolin-5-one and its metal complexes
Fouda, A. S., Al-Sarawy, A. A. and El-Katori, E. E. 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, Vol.60, No. 1, 2006, 5-9
|
|
|
Document type:
|
Článok z časopisu / Journal Article |
|
Collection:
|
Chemical papers
|
|
| Author(s) |
Fouda, A. S.
Al-Sarawy, A. A.
El-Katori, E. E.
|
| Title |
Potentiometric and thermodynamic studies of 3-methyl-1-phenyl-{ p -[ N -(pyrimidin-2-yl)-sulfamoyl]phenylazo}-2-pyrazolin-5-one and its metal complexes
|
| Journal name |
Chemical Papers
|
| Publication date |
2006
|
| Year available |
2006
|
| Volume number |
60
|
| Issue number |
1
|
| ISSN |
0366-6352
|
| Start page |
5
|
| End page |
9
|
| Place of publication |
Poland
|
| Publisher |
Versita
|
| Collection year |
2006
|
| Language |
english
|
| Subject |
250000 Chemical Sciences
250300 Organic Chemistry
|
| Abstract/Summary |
The 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+, UO 2 2+, 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.
|
|
|
