Synthesis And Characterization of N,N-Bis(2,4Dihydroxy( -1-Methylbenzylidene)Pyridine-2,6-Dicarbohydrazide And Studying Its Analytical Properties

Abstract

In This research the compound (N, N-Bis (2,4Dihydroxy( -1-Methylbenzylidene) Pyridine-2,6-Dicarbohydrazide ) was synthesized, That showed analytical properties of application importance; as analytical reagent for determination of metal ions by spectrophotometric methods. the compound (N, N-Bis (2,4 Dihydroxy( -1-Methylbenzylidene) Pyridine-2,6-Dicarbohydrazide ) was showed Characteristics of acid-basic indecator. The prepared compound has a yellow color in strong alkaline media and turns colorless at pH>=7.22; So it can be used as a indecator in adjustment titrations. The dissociation constants (pKa ) of the compound, was determined by two methods (Calculation and graphic method), which were equal to (pka₁=6.93±0.273) (pKa₂=9.63±0.077) respectively in (10%) dimethylformamide-water solutions.

The compound has been used as an Organic chelateing to form colored complexes with metal ions. Where the complex formed with copper ions Cu⁺² was studied by spectrophotometric methods, so the yellow complex had a maximum absorbance at (λ _max =425) at a range of pH values, and it was found that the complex was stable in a range of pH values ​​(pH = 4-6), and the molar extinction coefficient for this resulting complex was determined at the wavelength of the maximum absorption and its value was equal to (ε _λmax =19425l.mol^-1 cm^-1), mole Ratio and slop ratio. The ion reactive ratio (ion: reagent) were(3M:2L), Lambert - Beer's law was obeyed in the concentration rang of 5.58-14.88 ppm, and Sandel's sensitivity is (0.01195 μg .cm^-2), and the logarithm of the complex formation constant is calculated and equal to    . =7.207±0.302.(