Studies on some lanthanide complexes of acyclic, asymmetrical and symmetrical schiff bases

355-360Some new complexes of Ln(III) chloride [Ln (III)=La, Pr, Nd, Sm, Eu, Gd, TB and Dy] with 2,6-diacetylpyridine mono (2-thenoylhydrazone) (Hdapth) and 2,6-diacetylpyridine bis (2-thenoylhydrazone) (H2dapth) have been synthesized. Their chemical compositions have been established as [Ln(Hdapth]Cl2H2O)3]CI and [Ln(H2dapth]Cl(H2O)2]Cl2 from analytical, molar conductance and FAB mass data. The Hdapth and H2dapth are coordinated to the metal ions in tetrakis and pentakis fashion .The coordination number nine and eight around the metal ions are established from IR, NMR and electronic spectra, in Hdapth and H2dapth complexes, respectively. The emission spectra revealed symmetry of the ligand field around the metal ions in Sm(III), Eu(III) and Th(III) complexes.