Synthesis of calix[4]arenes for anion separations

Abstract

Two novel compounds, 25,27-[2,2’-[1,9-(2,5,8-triammonium)nonylene)-2,2’-diphenoxy]diethyl]-p-tert-butylcalix[4]arene(5c)and 25,27-[2,2’-[1,9-(2,5,98-hexamethylammonium)nonylene)-2,2’-diphenoxy]diethyl]-p-tert-butylcalix[4]arene (7b) were synthesized. (5c) was synthesized by hydrogenation its Schiff base analog with sodium borohydride, followed by acidifying the product with hydrochloric acid to yield an ammonium derivative of p-tert-butylcalix[4]arene. The compound was characterized by 1H-NMR spectroscopy, mass spectrometry and elemental analysis. (7b) was a methylammonium derivative of (5c), prepared by methylating the basic form of (5c) with methyl iodide and dimethyl sulfate and characterized by 1H-NMR spectrosocopy and mass spectrometry. Complexation studies with nitrate and carbonate ions by 1H-NMR spectroscopy technique were performed on (5c) ammonium derivative of three nitrogen sites, (7a) methylated derivative of two nitrogen sites and (7b) methylated derivative of three nitrogen sites. In all cases, the extent of interaction of carbonate ion was greater than nitrate ion. The methylammonium derivatives (7a) and (7b) could bind the anions to a lesser extent than (5c). The complex was obserbed to be 1 : 1 type, LA. (5c) showed a recognition for carbonate over nitrate ion.