An investigation of second coordination shell complexation of ferrioxamine B by crown ethers, natural ionophores, and other macrocycles through host-guest complexation of the pendant protonated amine group is presented. The influence of guest structure, host structure, solvation shell, and counter ion on host-guest assembly stability is discussed. Application of this form of molecular recognition to bulk liquid membrane transport of a stable metal complex is also presented. The significance of ionophore recognition of a metal complex in the context of iron bioavailability is discussed.