Synthesis and Characterization of 2- Acetyl Furan Benzoyl Hydrazone and its Applications in the Spectrophotometric Determination of Cu (II)

Abstract

The new chromogenic reagent 2-acetylfuran benzoylhydrazone (AFBH) is synthesised, studied its characteristic properties and applied for the spectrophotometric determination of Copper (II) for the first time. The reagent gives greenish yellow complexes with copper (II) in sodium acetate-acetic acid buffer medium of pH 6.5. The molar absorptivities of copper complex is 2.05 x 104 Lmol-1 cm-1. The colour reactions have been investigated for the micro spectrophotometric determination of copper (II) in aqueous medium and applied for various water and biological samples. Copyright: ©2017 Basha respectively corresponding to υ(NH) secondary, υ (C-H) aromatic stretch(phenyl), υ(C-H) aromatic stretch(Furanyl), υ(C-H) aliphatic stretching, υ(C=O) hydrazine, υ(C=N) azomethine, υ(C-C) aromatic ring, υ(C-C) aromatic ring, υ(C-C) aromatic ring, υ(C-N) stretch vibrations respectively.ii. 1H-NMR spectrum of AFBH: (CDCl3 +DMSO-d6) showed signals at 2.33(3H, s), 6.61-7.58 (3H, m) and 7.61-8.6(5H, m) and 10.70 (1H, s) due to CH3, furan and Benzene protons, -NH (imino) groups of hydrazone respectively.iii. Mass spectrum of AFBH: shows molecular ion peak is observed at m/z value of 251. This corresponds to molecular ion peak. It is [M + Na] peak and most intense peak. Another peak is observed at m/z value of 237. It corresponds to M -CH 3 (M minus CH 3 ). iv. The pKa values of AFBH:The pKa values of AFBH were determined by recording the UV-Visible spectra of micro molar (4 x 10-6 M) solution of the reagent at various pH values and by taking the arithmetic means of the values obtained from the measurements at different wavelengths determined spectrophotometrically using Phillip and Merritt method. The values of deprotonation of AFBH are 5.93 (pK1) and 8.66 (pK2) corresponding to the formation of enol form and conjugated mono anion form respectively.v. The compound shows strong absorption band in UV region due to π -π* transition. In alkaline medium (pH 8.0-10.0), this band is shifted towards higher wavelength due to formation of conjugated negative anion. The chromogenic characteristics of AFBH are given in Table 1. 6.0 Greenish yellow 0.2M sodium acetate -0.2M acetic acid (pH 6.5) was used in the present study. The standard Cu (II), solution (1 x 10 -2 M) was prepared by using analytical reagent grade Cu (CH 3 COO) 2 H 2 O. The stock solution of copper (II) was standardized using titrimetric and gravimetric methods respectively. Shimadzu 160A UV visible spectrophotometer equipped with 1.0 cm quartz cells and Elico Model LI-120 pH meter were used in present study.The reactions of some important metal ions were tested at different pH values. The samples were prepared in 25-ml volumetric flask by mixing 10ml buffer, 1ml of metal ion and 1.5ml of 0.001M AFBH solution. The reaction mixture was diluted to mark with distilled water. The absorbance was measured in 350-600 nm range against the reagent blank.An aliquot of metal ion in the Beer's law validity range 1.02 -10.2 μg/ml of Cu(II) ,10ml of buffer solution (pH 6.5) 2.5ml of DM...

Macrocyclic Metal Complexes of Tetradentate Hydrazone Ligand: Synthesis, Characterization and its Applications

“…A definite concentration of Fe(III) was added to ligand, FBH-L with little adjustment of pH using either nitric acid or sodium hydroxide. The determination was done on UVvis spectrophotometer at 250-900 nm wavelength at an interval of 1 nm with 1 s per wavelength measuring time [31,32]. The maximum absorbance was found at 310 nm.…”