Synthesis and complexing properties of a double-calix[4]arene crown ether

Treatment of p-tert-butylcalix[4]arene with tetraethyleneglycol ditosylate in the presence of potassium carbonate in acetonitrile afforded the first example of a double-calixcrown (1) in 52% yield. The double-calixcrown (1) was shown to form 1: 1 complexes with potassium and rubidium picrates in the solid state and in solution in chloroform. The stability constants of the alkali complexes have been determined in acetonitrile, as well as the phase transfer parameters from water to dichloromethane. © 1992 Kluwer Academic Publishers.