A study on the coordination chemistry of calixcrowns with metal ions in solution by NMR and XAFS

In order to study the coordination chemistry of calixcrowns in solution, the single crystals of 25, 27-bis-octyloxy-calix[4]arene-26, 28-crown-6 (BOC6) and 1, 3-alternate biscrown-6(BisC6) are presented in the paper. By using NMR and XAFS, the coordination behaviors of BOC6 and BisC6 in CDCl3 and NPME (o-nitro-phenyl methyl ether) or OA( n-octyl alcohol) with alkali metal ion are studied respectively. The results indicate that the symmetry of the crown ether chain is improved obviously as the cesium ion is imbedded in. The coordination number of cesium is seven and the complex structure with seven-oxygen coordination is stable in solution. One of the nitrate radical oxygen might coordinate with cesium directly.