title: Structural control of Schiff base ligands for selective extraction of copper(II).
abstract: Structural control of Schiff base ligands for selective extraction of copper(II) was investigated by changing pendant arms and the distance between two imine-N donor atoms in ligands. Di-Schiff base ligands, N,N'-bis(2-quinolylmethylidene)-1,2-diiminoethane (BQIE), N,N'-bis(2-pyridylmethylidene)-1,3-diimino-2,2-dimethylpropane (BPMP) and N,N'-bis(2-quinolylmethylidene)-1,3-diimino-2,2-dimethylpropane (BQMP), were used as complexation reagents for ion-pair extraction of divalent transition metal cations into nitrobenzene with picrate anion. The pendant arms affected the lipophilicity of ligand to nitrobenzene, due to their polarity. The distance between two imine-N atoms, on the contrary, was a factor of controlling the extraction selectivity. BQMP has both 2-quinolyl pendant arms and trimethylene backbone structure; use of BQMP as a complexation reagent led to the selective extraction of Cu2+ in the system.
authors.affiliation: Division of Basic Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan.
authors.forename: Syunichi
authors.initials: S
authors.lastname: Oshima
authors.forename: Naoki
authors.initials: N
authors.lastname: Hirayama
authors.forename: Koji
authors.initials: K
authors.lastname: Kubono
authors.forename: Hisao
authors.initials: H
authors.lastname: Kokusen
authors.forename: Takaharu
authors.initials: T
authors.lastname: Honjo