Syntheses and ion binding properties of novel cage molecules derived from homooxacalix[3]arene

Extraction Properties of <i>p</i>-Methyloxacalix[3]arene Methyl Ether for Alkali Metal Ions

“…This selectivity is different from that of the methyl and ethyl ethers of p-tert-butyloxacalix [3]arene [3,5] between two alkali metal ions is smaller than the corresponding difference in ΔG°t r,M+A . Namely, the extraction selectivity of MOC3A-Me for the alkali metal ions is governed by the extractability of the metal ions themselves.…”

“…The solvent extraction properties of p-tert-butyloxacalix [3]arene derivatives for various metal ions were investigated qualitatively based on the percent extraction for given conditions [2−8]. For example, methyl and ethyl ethers of p-tert-butyloxacalix [3]arene are known to show K + selectivity in the extraction of alkali metal picrates in a dichloromethane/water system [3,5]. To obtain more insight into the cation selectivity of oxacalix [3]arenes, quantitative data based on the equilibrium constants are necessary.…”

Homooxacalixarenes: II. Receptor properties

“…Note that oxacalixarene 69 with CH 2 SCH 2 moieties on the upper rim of the molecule (instead of CH 2 OCH 2 present in compound 68) did not at all extract alkali metal cations [52].…”

“…The ionophore features of conformationally rigid oxacalixarenes 68 and 69 with methoxy groups on the lower rim and capped by symm-tri-(methyloxy-or methylthia-)benzene cap on the upper rim [52]. For comparison tri-O-methyl derivative 3 was used.…”

Effect of Substituents on the Molecular Shapes of π‐Basic Macrotricyclic Receptors

“…[6] We recently reported the synthesis and properties of macrotricyclic molecules 1 and 2 [7] incorporating resorcinol-and mesitylene-derived "walls" and "cap", respectively (Figure 1), and complementing molecular cages derived from hexahomotrioxacalix [3]arene. [8] These compounds the "walls" and the "cap" on the shapes of the macrotricycles in solution ( 1 H NMR), the solid state (X-ray diffraction), and gas phase (calculations). Substitution of the lower position of the "walls" by Br (in 3) or MeS (in 4) has the same effect as ethyl substitution of the "cap" (in 2), that is, imparting high rigidity to the molecules and deforming their expected spherical shape to a cylindrical one.…”