Selective Separation of Hg(II), Pt(II), and Pd(II) Ions Using Silica-Gel-Bound Macrocycles Incorporating O₂N₂- and O₃N₂-Donor Sets

Abstract

Silica-gel-bound macrocycles (SGBMs) incorporating O2N2- and O3N2-donor sets have been synthesized, and their binding properties and selective separations toward Sr(II), Cu(II), Rh(III), Hg(II), Pt(II), and Pd(II) ions in aqueous HCl solution have been investigated. All binding constants decreased with increasing acid concentration, and values for Hg(II), Pt(II), and Pd(II) ions were greater than those for Sr(II), Cu(II), and Rh(III) ions. Pt(II) and Pd(II) ions or Hg(II) ion were selectively separated on stationary phases using SGB-2 and SGB-3, and these results were in accordance with expectations from binding constants.