title: Extraction behavior of divalent first row transition metal ions with N,N'-bis(2-hydroxyphenylmethyl)-N,N'-bis(2-pyridylmethyl)-1,2-ethanediamine and its derivatives.
abstract: For the fundamental study on the development of novel extractants, extraction behavior of divalent first row transition metals such as manganese, nickel, copper and zinc was studied with using N,N'-bis(2-hydroxyphenylmethyl)-N,N'-bis(2-pyridylmethyl)-1,2-ethanediamine (H(2)bbpen) and its derivatives as extractants. From the numerical analysis of the intricate extraction behavior of the metals, it was found that they were extracted into chloroform not only as uncharged chelate complexes but also as ion-pairs of charged complexes with a counter anion in aqueous solution. In other words, these ligands seemed to act not only as divalent hexadentate extractants but also as monovalent tri- or tetra dentate ligands, forming positively charged complexes. Furthermore, the order of the extractabilities between the metals did not coincide with the Irving-Williams series of stability because of the 'cavity size' in the ligands and the structural rigidity of them.
authors.affiliation: Department of Chemistry, Faculty of Science, Kanazawa University, Kakuma-machi, Kanazawa 920-11, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Hirayama
authors.forename: N
authors.initials: N
authors.lastname: Ichitani
authors.forename: K
authors.initials: K
authors.lastname: Kubono
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuoka
authors.forename: H
authors.initials: H
authors.lastname: Kokusen
authors.forename: T
authors.initials: T
authors.lastname: Honjo