SYNTHESIS AND COORDINATION CHEMISTRY OF A NOVEL BIS(BENZO CROWN-ETHER) SUBSTITUTED CALIX[4]ARENE THAT CAN SIMULTANEOUSLY COMPLEX CATIONS AND ANIONS

New calix[4]arene compounds substituted at the lower rim by four (L(3)) or two (L(6)) benzo-15-crown-5 (2,3,5,6,8,9,11,12-octahydro-1,4,7,10,13-benzopentaoxacyclopentadecine) groups respectively have been prepared. Proton NMR co-ordination studies with sodium and potassium cations in deuteriated acetonitrile revealed that L(3) forms L(3) . 5M(+) (M(+) = Na+ or K+) solution stoichiometric complexes consisting of an alkali-metal cation bound in each of the four crown ether moieties and one occupying the tetraamide lower-rim cavity. Compound L(6) complexes K+, Ba2+ and NH4+ exclusively at the crown ether binding sites in a 1:2 intramolecular sandwich stoichiometric fashion. A crystal-structure determination of [KL(6)][l(3)] has been carried out. Although neither L(3) nor L(5) coordinates anions the potassium and ammonium complexes [ZL(6)]PF6 (Z = K+ or NH4+) form 1:1 complexes with Cl-. NO3-, HSO4- and H2PO4-. Stability constant evaluations have shown that the strongest anion complexes are produced with H2PO4- and HSO4-.