Switching the Ion Selectivity from Fe³⁺ to Al³⁺ by a Triazole‐Appended Calix[4]arene‐Based Amphiphile^†

Abstract

A triazole appended benzaldehydic lower rim derivative of calix [4]arene (L) has been synthesized and was thoroughly characterized. In CH 3 CN solution, the L showed greater sensitivity for Fe 3 + by a 5-fold increase in the absorbance and 37% quenching in the fluorescence intensity, by forming a 1:1 complex. The Fe 3 + induces aggregation in L as studied by microscopy. The Langmuir film formed at the air-water interface was characterized by pressure-area isotherm and Brewster angle micrographs, both in the presence and absence of metal ions. The Langmuir films of pure L, {L + Al 3 + } and {L + Zn 2 + } were transferred onto H-terminated Si-wafer and characterized using Atomic Force Microscopy, contact angle, Grazing Incidence Fourier Transform Infrared Spectrscopy and X-ray Photoelectron Spectroscopy. The study resulted selective binding of Al 3 + to the Langmuir film of L among the nine metal ions studied. Thus, the calix[4]arene-conjugate L is sensitive and selective to Fe 3 + in acetonitrile solution whereas to Al 3 + in Langmuir film and hence acts as an ion switch depending upon the physical state of L.designed in the light of the following aspects: (i) The calix [4] arene core is required for the presence of arene compartment and also to provide a platform in order to build the arms with [a] R.

Switching Ion Binding Selectivity of Thiacalix[4]arene Monocrowns at Liquid–Liquid and 2D-Confined Interfaces

“…There has been a unique study of calixcrown-ethers in Langmuir monolayers, which revealed Cs + /Na + selectivity [ 21 ]. Intriguingly, switching of metal ion selectivity in calixarenes with the transition from liquid phase to air–water interface has been recently documented [ 22 ]. Thus, comparison of various environments is highly desirable in the study of binding behavior of these host molecules.…”

Calixarene-mediated host–guest interactions leading to supramolecular assemblies: visualization by microscopy

“…The assembly or the 2-dimensional The molecular distribution can also be understood from the microscopy when these networks/layers are transferred onto a solid substrate and studied further. [34][35][36] Concentration dependence on the nature of the host surface at the air-water interface Mixing of 1,2-dipalmitoyl-sn-glycero-3-phospho-(1 0 -rac-glycerol) (DPPG) with p-tert-butyl calix [6]arene (L 17 ) was studied by Langmuir monolayers by taking these at different mole ratios. 34 At the lower proportions of L 17 , the interactions between the DPPG and calix units are attractive due to the presence of hydrophobic tails of DPPG and the t-butyl units of calix.…”

“…The molecular distribution can also be understood from the microscopy when these networks/layers are transferred onto a solid substrate and studied further. 34–36…”

Ratiometric Cu2+ Binding, Cell Imaging, Mitochondrial Targeting, and Anticancer Activity with Nanomolar IC50 by Spiro-Indoline-Conjugated Calix[4]arene

“…Calix[4]arene platform is well known in the literature for its ease of functionalization at its upper and lower rims. 1,2 The resulting derivatives of calix[4]arene have been developed for various applications, such as host–guest interactions, 3−7 metal-ion 8−11 and anion sensing, 12 and drug delivery. 13,14 Spiro-indoline-based systems are known for their acido-, solvato-, thermo-, and photochromic behaviors.…”

“…Calix­[4]­arene platform is well known in the literature for its ease of functionalization at its upper and lower rims. , The resulting derivatives of calix[4]­arene have been developed for various applications, such as host–guest interactions, − metal-ion − and anion sensing, and drug delivery. , Spiro-indoline-based systems are known for their acido-, solvato-, thermo-, and photochromic behaviors. − Derivatives possessing spiro-indoline moieties were reported to have anticancer properties . Although the pyridinium moieties are known for their mitochondrial targeting ability, the quaternary nitrogen-containing spiro-indoline derivatives have not been explored in this direction.…”