Synthesis of p-tert-butylthiacalix[4]arene and its inclusion property

A practical method for the synthesis of p-tert-butylthiacalix[4]arene (TC4A ), in which the methylene bridges of p-tert-butyl-calix[4]arene (C4A) are r eplaced by epithio groups, is presented by heating a mixture of p-tert-buty lphenol, elemental sulfur S-8, and NaOH as a base catalyst in tetraethylene glycol dimethyl ether. The inclusion behavior of TC4A for a wide range of solvent molecules is examined by recrystallization, showing preference for the guests depending upon the size and/or the substituent of the guests. Th e X-ray structure of a 1:2 host-guest complex of TC4A with 1,2-dichloroetha ne reveals that one guest molecule is included in the cavity of TC4A, while the other is included in the crystal lattice to form a clathrate-type comp lex. It is shown that the inclusion in the cavity is attained by a cooperat ive deformation of both the host and the guest. (C) 2000 Elsevier Science L td. All rights reserved.