Calix[4]arene-5,11,17,23-tetrasulfonate as an Analytical Reagent for Cerium(III) Ion

Abstract

Calix[4]arene-5,11,17,23-tetrasulfonate (1) reacts with cerium(III) ion in alkaline solution to form a colored complex (λmax = 417 nm, ε = 1.09 × 104 1 mol−1 cm−1). The max coloration reaction is specific for cerium among rare-earth elements. The coloration mechanism was discussed on the basis of the stability constants.

Effect of Lower‐Rim Alkylation of p‐Sulfonatocalix[4]arene on the Thermodynamics of Host–Guest Complexation

“…This observation suggests that the ring-current effect of SC4A-Bu is not as strong as that of SC4A, corresponding to a lower π-electron density of the SC4A-Bu cavity. This can be rationalized in terms of the protonation constants of SC4A, [23,24] which predict that at least one phenol group is deprotonated near neutral pH and, thus, is strongly electron-donating.…”

“…The complexation of SC4A and SC4A-Bu with TMA was measured at two pH values (pH = 2.0 and 6.0). According to the protonation constants of SC4A, [23,24] at least one phenol group is deprotonated at pH = 6.0, whereas all the phenol groups are protonated at pH = 2.0.…”

Highly Sensitive Spectrofluorometric Determination of Terbium(III) with Tetrasodiumcalix[4]arene-p-tetrasulfonate

“…4 In this study, 5 ml of 0.2 M sodium hydroxide was added into the sample solution to adjust pH to ca. 12.3 in the 25 ml volumetric flask.…”

“…In this study, tetrasodiumcalix [4]arene p-tetrasulfonate, Na4CALX-S4, was selected as a new oxygen-ligand because its terbium complex shows high luminescence quantum yield (0.…”

Synthesis and adsorption properties of p-sulfonated calix[4 and 6]arene-intercalated layered double hydroxides

“…The calixarene cavity is capable of molecular recognition in solution, which is of great interest for application in the remediation of contaminated groundwater and industrial effluents [31][32][33][34][35][36][37][38].…”