Transport of Ca^(2+) Ion through a Bubbling Pseudo-emulsion Liquid Membrane with Calixarenes and Calixcrowns as Carriers

Several new calixcrowns were synthesized and characterized. The transport of Ca 2+ ion was investigated through a bubbling pseudo emulsion liquid membrane with these calixcrowns, the parent calixarenes ( n =4, 6, 8) and the ester, acid derivatives of calixarene as mobile carriers. The effects of the initial concentrations of Ca 2+ ion in the source phase and the initial pH difference (ΔpH) between the receiving phase and the source phase were studied. The results suggest that there are two different transport mechanisms. The transports using calixarenes and their ester, acid derivatives as carriers represent a proton coupled co transport with a flow of protons in the opposite direction, while the transports using the calixcrowns as carriers exhibit the characteristics of an anion coupled co transport with a flow of anion in the same direction.

Nano-baskets of Calix[4]-l,3-crown in Emulsion Membranes for Selective Extraction of Alkali Metal Cations

Nano-assisted inclusion separation of alkali metals from basic solutions was reported by inclu sion-facilitated emulsion liquid membrane process. The novelty of this study is application of nano-baskets of calixcrown in the selective and efficient separation of alkali metals as both the carrier and the surfactant. For this aim, four derivatives of diacid calix[4]-1,3-crowns-4,5 were synthesized, and their inclusion-extraction parameters were optimized including the calixcrown scaffold （4.4%, by mass） as the carrier/demulsifier, the commercial kero sene as diluent in membrane, sulphonic acid （0.2 mol.L-1） and ammonium carbonate （0.4 mol.L-1） as the strip and the feed phases, the phase and the treat ratios of 0.8 and 0.3, mixing speed （300 r.min-1）, and initial solute concentration （100 mg.L-1）. The selectivity of membrane over more than ten interfering cations was examined and the re sults reveled that under the optimized operating condition, the degree of inclusion-extraction of alkali metals was as high as 98%-99%.

Synthesis of novel calix[4]crown telomers and selective extraction of cesium ions

p-tert-Butylcalix[4]diazacrown-4 telomer, which contains hard and soft ion binding sites, was synthesized. It exhibited high selectivity toward cesium ions. The binding sites may complex alkali metal ions selectively.

Synthesis and Extraction Studies of Calix[4]-Crown-4 Oxime Derivatives

The article comprises synthesis of calyx[4]-oxa-crown, and calix[4]-thia-crown compounds containing nitrile groups (3a, 3b) and amino groups (4a, 4b) and their corresponding oxime derivatives (5a, 5b) and liquid-liquid extraction studies of these compounds. The oxime derivatives of compounds (5a, 5b) have been synthesized by reacting of di-n-butylamino derivatives of calix[4]-oxa-crown, and calix[4]-thia-crown compounds (4a, 4b) with amphi-chloroglyoxime in methanol-THF. Their cation and anion transfer studies were performed by using liquid-liquid extraction procedure. It has been concluded from the observations that the compound 3a shows a good extraction behavior toward Na+ ion in the presence of other metal cations. Whereas, its oxime derivatives transfers all of the metal cations used in the liquid-liquid extraction studies.

Crystal Structure of Calix［4］（dioxo） crown－6 Acetonitrile（1：3） Inclusion Complex

The X-ray crystal structure of the inclusion complex of p-tert-butylcalix [4] crown-6 with actonitrile is reported. C54H70O10·3CH3CN, Mr=1002. 3 ,monoclinic, space group C2/c with cell dimensions of a=23.587(7),b=21.153(6),c=15.608(8) A,β=116.99(3)°,V=6939.2 A3,Z=4, F(000)=2160,Dc=0.959 g/cm3,μ=1.114 cm-1; R=0.088 for 2066 reflections with I>3σ(I).The calixarene subunit exists in a distorted cone conformation. One of the three acetonitrile molecules is located in the intracavity of the calixarene subunit and the other two in the intermolecular channels.

Synthesis of novel calixcrown derivatives with selective complexation towards cesium ions

A series of novel calix[4]arenecrown-6 derivatives with an alkenyl loop of various sizes 5-8 were synthesized via intramolecular ring closing olefin metathesis and characterized by ~1H NMR,^（13）C NMR and ESI-HRMS.Their complexation property towards cesium ion was studied by ^1H NMR technique.Two-phase extraction of alkali metal ions using UV-vis spectroscopy revealed remarkably different extractabilities.These results indicate that the complexation capacities towards cesium ions can be tuned and controlled through cooperative regulation of the strain of the loop and conformational change of calixcrown skelton.

Synthesis and Dyes Adsorption Properties of Calix[4]crown-grafted Chitosan Chelating Polymer

By the Schiff-base condensation of formacyl calix[4]crown（2） with raw chitosan, a novel calix[4]crown- grafted chitosan chelating polymer（3） was conveniently prepared in good yield. The structure of polymer 3 was con- firmed by elemental analysis, infrared（IR） spectrometry and X-ray diffraction（XRD） analysis. The elemental analysis suggests that the grafting degree of calixcrown unit was 22% on the amino groups of chitosan. The morphological characteristic of polymer 3 was studied by scanning electron microscopy（SEM）. Polymer 3 possessed loose porous and smooth morphology of surface. The dyes adsorption abilities of polymer 3 for a series of organic dyes[Orange I（OI）, Neutral red（NR）, Victoria blue B（VB） and Brilliant green（BG）] were studied by solid-liquid adsorption expe- riments. The adsorption percentages increased from 45%-60%（raw chitosan for dyes） to 75%-90%（polymer 3 for dyes）. The highest adsorption percentage reached 89% for VB. The saturated adsorption capacities for OI, NR, VB and BG were as high as 622, 564, 854 and 781 mg/g, respectively. The adsorption abilities kept stable at 70%-90% in the scope of pH=5-9. The adsorption abilities for anionic dye（OI） decreased gradually with the increase of pH and the opposite trend was observed for cationic dyes（NR, BG, VB）. The adsorption percentages were 70%--90% after five times＇ cycles for adsorption.