Hard–Soft Receptors, Tetrakis[(N,N-diethylaminocarbonyl)methoxy] thiacalix[4]arene Derivatives with cone and 1,3-alternate Conformation

Direct O-alkylation of p-tert-butyltetrathiacalix4]arene with N,N-diethylchloroacetamide afforded two conformational isomers (1,3-alternate and cone) of tetrakis(N,N-diethylaminocarbonyl)methoxy]thiacalix4]arene and 1,3-disubstituted bis(N,N-diethylaminocarbonyl)methoxy]thiacalix4]arene, depending on the base used. The complaxation behaviors of the tetrakis isomers were assessed by ¹H NMR titration experiments. Evidence of 1:2 (homo- and hetero-dinuclear) complexes formation of 1,3-alternate-tetrakis(N,N-diethylaminocarbonyl)methoxy]thiacalix4]arene with alkali (K⁺ and Na⁺) or transition (Ag⁺) metal ions was obtained. Interestingly, it was found that the cone-tetrakis(N,N-diethylaminocarbonyl)methoxy]thiacalix4]arene required a prior Ag⁺ complexation to form 1:2 heterodinuclear complex. Received in final form: 26 January 2005