Synthesis, characterization, and thermal analysis of ternary complexes of nitrilotriacetic acid and alanine or phenylalanine with some transition metals

Abstract

Ternary complexes of Co(II), Ni(II), Cu(II), and Zn(II) with nitrilotriacetic acid as a primary ligand and alanine or phenylalanine as secondary ligand were prepared in slightly acidic medium. The structures of the complexes were elucidated using elemental, IR, molar conductance, magnetic moment, UV-Vis spectrophotometry, and thermal analyses. The ternary complexes were isolated in 1:1:1 (M:HNTA:alaH) ratios, and the molecular structures were found to be [M(HNTA)(alaH)(H2O)2]. Thermogravimetric analysis confirmed this structure and that the water present is coordinated to the central metal atom. UV-Vis spectra showed that the complexes have octahedral symmetry. © 2010 Akadémiai Kiadó, Budapest, Hungary.