Tetradipicolyamine-substituted resorc[4]arene cavitands: I. Anion binding and transition metal assembled coordination cages and nanoarchitectures. II. Polymer inclusion membranes applied to anion separations

Anions binding has been achieved with a resorc[4]arene substituted with four 2,2'-dipicolylamine moieties on the upper rim. This anion receptor was found to provide binding of anions such as H2PO 4-, Cl-, F-, CH3CO2-, HSO4 -, and NO3- through multiple ammonium cationic sites. Our cavitand appears to be providing two identical receptor sites formed by two 2,2'-dipicolylamine ligand pendant groups each, facilitating the simultaneous binding of two anions. The association constants for these anions are on the order of log K 5, in a solvent of intermediate dielectric constant CD3CN. This represents significant binding compared to other cavitands with nitrogen pendant groups. Intramolecular binding of anions between two dipicolylamine groups is indicated based on comparison to a model system and by semi-empirical PM3 molecular modeling.; Novel new carriers for facilitated membrane transport of anions have been prepared consisting of transition metals ions (Fe3+, Cu 2+, Zn2+) complexed with derivatives of bis(pyridylmethylamine). These carriers have been included in cellulose triacetate (CTA) based polymer inclusion membranes (PIMs), which have been used to study competitive transport between halides (F-, Cl-, Br -, I-) and between a series of oxoanions (SeO42-, SO4-, NO3-, and ReO4-). Varying plasticizers were used in the membranes to provide solubility of the metal carrier complexes. Permeabilities of oxoanions were observed to increase with the use of 0.05 M KCl as an antiport solution. The metal carriers were observed to attenuate the order of the Hoffmeister series by providing high selectivites for perrhenate over other oxoanions. Permselectivity for ReO 4-/NO3- of over 300 was observed for a PIM using ethyl phthalyl ethyl glycolate as plasticizer, the N,N-bis(pyridylmethyl)undecylamine carrier complexed with Zn(II), and an antiport anion solution of 0.05 M KCl.; Resorcinarene-based cavitands derivatized with four 2,2' -dipicolyamine moieties have been prepared and complexed with a variety of transition metals, namely Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II), which yield metal-complexed cavitands, metal-assembled cages and larger nanometer sized architectures. Characterization and study of these metal complexes was performed by UV-visible spectroscopy, 1H-NMR spectroscopy and FTICR/MS. FTICR/MS evidence indicates the inclusion of solvent and neutral species in cage molecules and multiple guests inside the larger nanoarchitectures.