A Study Simple, Economic And Rapied Potentiometric Method
1218 WordsSep 29, 20165 Pages
In this study simple, economic and rapied potentiometric method was used to calculated proton-ligand stability constant of [2-oxo-2H-chromene-3-carbohydrazide] and metal-ligand stability constant of its complexes with metal ion (Mn+2 and Cd+2).
This method has been employed at three different temperatures 298k,308k and 318k and at an ionic strength of 1N NaCl.
The thermodynamic parameters (G, (H and (S were studied from logk at three different temperatures.
Coumarin derivatives are used in the filed of polymer, medicine and biology sciences. They are also present in the actions of plant growth hormones(1,2) and used in cosmetics(3), lasyer dyes(4),perfumes(5) and cigarettes(6).
Various techniques have been developed to determination coumarin and its derivatives, such as spectrofluorimetric(7), HPLC
(8,9), capillary gas chromatography(10) and fluorescent probes(11).
The aim of this study was developed simple potentiometric method for the determination coumarin derivative [2-oxo-2H-chromene-3-carbohydrazide] and its complexes with Mn+2 and Cd+2.
Material and method pH meteric titration were carried out with jenway 3020 pH meter, Varian UV–Vis spectrophotometer and All chemicals were analytical grade supplied by BDH and Fluka.
Procedure of ligand [2-oxo-2H-chromene-3-carbohydrazide]
The ligand papered as reported in the literature(). Cumarin-3-carboxylic acid ethyl ester (1mol) was mixed with 50 ml hydrazine hydrate and the mixture was refluxed at