Synthesis, Characterization and Thermal Study of New Transition MEtal Complexes Derived from 3-Acetylcoumarine

Abstract

The synthesis, structure, physico-chemical and thermal investigation studies of some transition metal complexes ofCo(II),Ni(II) Cu(II) and Cd(II),withtwo ligands derived from 3-acetyl coumarine. The two ligands ligands(L 1 and L 2) were synthesizedvianucleophilic substitution of 3-bromoacetylcoumar with potassium thiocyanateandethanolic solution of 1,2-phenlendiaminein respectively. The metal complexes of Co(II), Ni(II) Cu(II) and Cd(II),with L 1 and L 2 were prepared and isolated in the solid state then characterized by CHNM elemental spectral FT-IR, 1 H, 13 C NMR , Mass spectra,UV-Visible spectra. The thermal study (TG-DSC) of some complexes was carried out in nitrogen gas which assisted in determination the proper structure and formula of such complexes. The ligand acts as bidentate, through OO or NO, neutral in coordinating the metal ions under study. The results obtained from elemental analyses,magnetic susceptibility and electronic spectra suggested that all metal complexes were formed in 2:1 molar ratio of ligand to metal with octahedral structures. The complexes are found to be soluble in DMF and DMSO. The TG-DSC study revealed that the metal complexes were thermally stable with point decomposition over 350 0 C as well as the percent in loss of weight up on decomposition at inert conditions of nitrogen atmosphere has reported the proposed formula.