Tyo Sone

Synthesis and properties of sulfur-bridged analogs of p-tert-Butylcalix[4]arene☆

Abstract p - tert -Butylcalix[4]arene analogs in which up to four methylene bridges were replaced by sulfur bridge(s) were synthesized. NMR studies indicated that the thiacalixarenes were conformationally much more flexible than the parent calixarene in CDCl 3 solution; the flexibility was greater with increasing number of the sulfur bridge. The thiacalixarenes serve as inclusion hosts for some organic compounds, forming 2:1 (host:guest) crystalline complexes in many cases.

Liquid-liquid extraction of iron(III) and gallium(III) with macrocyclic Schiff bases containing bisphenol A subunits

Abstract The quantitative extraction of iron(III) and gallium(III) was investigated with the recently synthesized macrocyclic Schiff base containing bisphenol A subunits. The phenol groups in the Schiff base moiety led to a large increase in the percent extraction of trivalent metal ions. The substitution of methoxy groups for phenolic OH ligands resulted in a marked decrease in the extractability of metal ions, and no iron(III) was extracted. The corresponding acyclic Schiff base was found to have a reasonable reactivity toward metal ions and a better solubility in organic solvents. The iron(III) and gallium(III) complexes with macrocyclic and acyclic Schiff bases were quantitatively extracted into nitrobenzene without the presence of bulky counter anions. A single extraction gave a good separation of iron(III) from iron(II) in the mole ratios 4:1 to 1:3. The red iron(III) complexes can be used for the extraction-spectrophotometric determination of iron(III). The apparent molar absorptivity at 518 nm is 5.43 × 10 3 l mol −1 cm −1 .

Liquid—liquid extraction of transition metal ions with macrocyclic Schiff bases containing phenol or thiophene subunits

Abstract Two types of macrocyclic Schiff bases containing either thiophene or phenol subunits were synthesized and the effect of ligand atoms on the liquid—liquid extraction of bivalent transition metal ions was studied. The phenol groups in the macrocycle led to a large increase in the extraction of transition metal ions. The least stable manganese(II) complex was extracted quantitatively into nitrobenzene as an ion pair with tetraphenylborate ion at pH 9. Copper(II) was selectively extracted from weakly acidic media, permitting its separation from manganese(II), cobalt(II), nickel(II) and zinc(II). The composition of extracted copper(II) species was evaluated. The extractability of metal complexes with a cyclic tetraaza Schiff base has been compared with that of the corresponding acyclic Schiff base.

Syntheses of p-tert-butyloxocalix[4]-, [5]-, and [6]arenes and their behavior in solution

p-tert-Butyloxocalix[4]-, [5]-, and [6]arenes were synthesized by a stepwise procedure. NMR studies demonstrated that strong intramolecular hydrogen bonding between the bridging CO and neighboring phenolic OH groups in the oxocalixarenes weakened the circular hydrogen bonding of the parent calixarenes, resulting in greater conformational flexibility of the oxocalixarenes.

LIQUID-LIQUID EXTRACTION OF COPPER(I) AND COPPER(II) AS ION-PAIRED COMPLEXES WITH ACYCLIC 2-THIENYL-CONTAINING POLYTHIOETHER AND TRIPHENYLMETHANE DYE ANION

Three acyclic polythioethers containing 2-thienyl units at both ends were synthesized and the effect of substituent on the extraction of copper(II) was studied. The methyl groups in the terminal thiophene ring have imparted an appreciable degree of increase in the percent extraction of copper(II), while the introduction of chlorine atoms into the 2-thienyl unit resulted in the reverse effect. Among the counter dye anions examined, tetrabromophenolphthalein ethylester was the best one for copper(II) extraction. The composition of extracted species was evaluated to be 1∶2∶2 (Cu(II)/polythioether/dye anion). Quantitative extraction of copper(I) was attained as complexes with various triphenylmethane dyes, i.e., bromocresol green, bromothymol blue, bromo-phenol blue and pyrogallol red. Copper(I) in organic phase was completely back-extracted with 2 mole/l sulfuric acid containing 10% hydrogen peroxide.

Facile Syntheses of Homothiacalixarenes

Abstract Homothiacalixarenes were conveniently prepared from the reactions of bis(chloromethyl)phenol-formaldehyde trimers with alkanedithiols in good yields.

Synthesis and inclusion properties of teraazametacyclophanes containing bisphenol A unit

Abstract Novel 26-membered, 8b and 10, and 28-membered tetraazameta-cyclophanes, 9, containing two bisphenol A units were synthesized; 8b and 9 in five steps from bisphenol A via the corresponding macrocyclic tetraimine Schiff bases, while 10 in three steps. The macrocyclic Schiff bases were obtained in high yields (> 80%) by [2 + 2] cyclization of the diformyl or bischloromethyl derivatives of bisphenol A dimethyl ether with the corresponding aliphatic x,ω-diamines or piperazine under high dilution conditions, making a remarkable synthetic feature. The macrocycles formed crystalline inclusion compounds with a variety of neutral organic molecules. Complexation studies by Diederichs solid-liquid extraction method revealed that the metacyclophanes formed complexes with phenanthrene, anthracene, pyrene, and acenaphthylene in acidic aqueous solution with assocition constants Ka up to 1.5 × 105 M−1.

Synthesis of Chiral Tetrahomodiazacalix[4]-and [6]Arenes Bridged by Cystine Peptide

Abstract Bicyclic tetrahomodiazacalix[4]- and [6]arenes bridged by a cystine peptide were easily synthesized from the cyclization reactions of bis(chloromethyl)phenol-formaldehyde oligomers with cystine peptides in DMF in moderate yields.

FACILE FORMATION OF CALIX[4, 5, 6, AND 9]ARENE ANALOGS HAVING THE INTRA- AND EXTRA-HYDROXYL GROUPS

ABSTRACT Calix[4, 5, 6, and 9]arene analogs bearing the intra- and extra- hydroxyl groups were prepared by the reactions between bis(hydroxymethyl)-bisphenol-A and phenol or phenol-formal-dehyde oligomers under acid catalyzed reaction condition in moderate yields.