Preparation and spectrophotometric study of 2[2-(5-bromo thiazolyl) azo] -4-methoxy phenol

ABSTRACT: A new thiazolylazo dye 2[2-(5-bromo thiazolyl) azo]-4-methoxy phenol (BrTAMP) was prepared by coupling reaction between 5-bromo thiazolylazonium chloride with 4-methoxy phenol in alkaline alcoholic solution. The structure of azo ligand has been characterized by Mass spectrometry, 1HNMR, UV-visible and FT-IR spectrophotometry. Three new complexes of Cu (II), Ni (II) and Ag (I) ions were prepared and identified by UV-visible spectroscopy, molar conductivity measurement, and FT-IR spectroscopy. The spectral and analytical data show that the reagent is tridentate and coordination with metal ions are: (i) the azo N atom which adjacent to methoxy phenol radical, (ii) thiazole N atom and (iii) the phenolate O atom. The metal ligand ratio (M:L) in alcoholic aqueous solutions determined by the “mole ratio” method and by Jobe's method, both indicate 1:2 for Cu (II) and Ni (II) complexes and 1:1 for Ag (I) complex. Stability constants for the complexes were also calculated from spectrophotometric data. While octahedral configuration is suggested for Ni (II) and Cu (II) complexes, tetrahedral is suggested for Ag (I) complex. The solid complexes are found to have the general formula [ML2].H2O where M = Cu (II) or Ni (II) ions and [ML. H2O] where M = Ag (I) ion. The analytical applications using the ligand to determine Cu (II) in a sample of human blood and Ni (II) in a sample of water from the Euphrates River were carried out. Keywords: Thiazolylazo Ligand, Coupling Reaction, Metal Complexes, Characterization and Analytical Application. …………………………………………………………………………………………………………………………………………………………………………………………………………