The synthesis of a novel host blocked in the cone conformation and bearing m-methoxycarbonylbenzyl groups at the lower rim is described. X-ray crystal structure analysis revealed that action of one molecule of compound upon one molecule of CH 3CN or one molecule of CH 3NO 2, forms an intramolecular inclusion complex, respectively, by CH 3-π interactions. The complex of L with tetrabutyl ammonium bromide(TBAB), L·TBAB, was obtained. The results of DTA-TG and XRD analysis of L·TBAB can also be considered as an intramolecular inclusion complex.
Two new substituted calix[4]arene derivatives 2 and 3 were synthesized by the reaction of calix[4]arene with methyl o-bromomethyl-benzoate in the presence of potassium carbonate under nitrogen. Their compositions and structures were confirmed by elemental analysis, IR, 1H NMR and 13C NMR. Both the compounds are in the cone conformation. The percent extraction of the tetrasubstituted calix[4]arene derivative 2 for Li +, Na +, K + and Cs + are 6.8, 19.4, 69.8 and 7.1, respectively, indicating that derivative 2 extracts K + better than Li +, Na + and Cs +. The higher selective complexation of compound 2 with K + elucidated that the radius of potassium cation may be matched with the inclusion cavity formed by the carbonyl and phenoxy groups. There is only a little extractivity of disubstituted calix[4]arene derivative 3 for alkali metal ions.
