Complexation behaviour of p-tert-butylcalix[4]arene and p-tert-butylcalix[6]arene towards acetone

Abstract

Novel 1:1 complexes of acetone with p-tert-butylcalix[4]arene and p-tert-butylcalix[6]arene were prepared and characterized by TGA, DSC, PXRD and ¹³C and ²H solid-state NMR. The behaviour of both molecules towards acetone is very similar, with the same orientation of the guest, and the same activation energy for the rotation of the C–D bond of acetone about its threefold axis. This is interpreted in terms of the pinched-cone conformation of p-tert-bultylcalix[6]arene in the complex, which can be viewed as two edge-sharing p-tert-bultylcalix[4]arene molecules in the cone conformation.