U.V-Visible Spectral Analysis of Synthesized Meso-Tetraphenyl Porphin(TTP) and Some of its Metal Complexes

Abstract

This work investigated the effect of the central metal atom on the U.V-Visible spectra of metalloporphyrins, with correlations made between the ligand and the various metal derivate. The porpphyrin ligand, meso-tetraphenylphorphin, was synthesized by direct reaction between pyrole ring and benzaldehyde, and the metal complexes from the acetate of the divalent metal. Solubility tests of the ligand and the complexes were carried out. They were found to be soluble in many organic solvents such as chloroform, dichloromethane, benzene and pyridine, with the extent of solubility varying from one complex to the other. Solutions of 10-6moldm-3of the tetraphenyl porphin and its Mn(II), Cu(II), Ni(II), Co(II), Zn(II), Mg(II) and Hg(II) complexes were prepared and scanned over frequency range of 300-700nm using λ-3 Perkin-Elmer U.V/Visible spectrophotometer. The U.V/Visible properties of the meso-tetraphenylporphin complexes were found to be depend on the central metal atom. The differences were quite definite which may probably be attributed to whether or not a d-metal orbital is available for covalent bonding. Those metals such as Mn, Co, Ni, and Cu which have such orbitals have spectra which are shifted to the blue region and characterized by low intensity first band, while metals in which are covalent bonding is limited to s and p orbitals of the metal, such as Mg and Hg, have spectra which are shifted to the red region and which are characterized by a much more intense first vibrational band.