Synthesis and selective transport properties of cleft-type ionophores having two convergent hydroxamic acid functions

A series of cleft-type ionophores having two convergent hydroxamic acid fun ctions are prepared and their selective ionophoric properties toward heavy metal and transition metal ions have been investigated. Hydroxamic acids 3 exhibited a prominent selectivity toward heavy metal ions of Hg2+ and Pb2+, and transition metal ions Of Cu2+ over other transition metal and alkaline earth metal ions from slightly acidic source phase (pH 6) to an acidic rec eiving phase (pH 1). Selective ionophoric properties toward Pb2+ and Cu2+ i ons over other surveyed metal ions are also confirmed by the FAB-MS measure ments.