Urea derivatives of calix[4]arene 1,3-alternate: an anion receptor with profound negative allosteric effect

Synthesis of Photo-Switchable Derivatives of p-tert-Butyl Thiacalix[4]arenes Containing Ethoxycarbonyl and 4-Amidoazobenzene Fragments in the Lower Rim Substituents

“…It is also known that the realization of negative allosteric effect interfering with a complex formation can take place at the substrate binding by derivatives of calix-and thiacalix [4] arene in 1,3-alternate conformation. [33,34] Thus, the existence of the hydroxyl groups in structure of the receptors 2 and 4 and also their cone conformation are necessary criterion for anion binding.…”

A new anthracene derivative of calix[4]arene as a fluorescent chemosensor

“…Intramolecular cavities of calixarenes, formed by the phenolic rings, can host complementary cations, 14−16 anions, 17,18 and neutral molecules 19 especially when several binding sites are preorganized at the wide or narrow rim of the macrocycle.…”

Anion Receptors Based on Calixarenes

“…To compare the complexation ability of amide versus urea groups, the calixarenes 29e and 29d bearing two functions on the upper rim were prepared [45]. The NMR titration experiments (CDCl 3 :CD 3 CN=4:1) clearly proved much stronger complexation of H 2 PO 4 -by ureido derivative 29d (K 29d =2,300 M -1 ) than by the amide receptor 29e (K 29e =4 M -1 ).…”

“…The corresponding tetraureido derivative 35 was designed [45] as a ditopic anion receptor with two ureido functions preorganised at both sites of the 1,3-alternate conformation. Surprisingly, the Job plot unambiguously confirmed the exclusive formation of only 1:1 complexes with halides, acetate or benzoate.…”