• Analytical Science and Technology
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• v.16 no.4
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• pp.333-338
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• 2003

Inclusion selectivity of a three-dimensional piperazine-ligated cyanocadmate host complex, $[Cd_x(CN)_{2x}\{HN(CH_2CH_2)_2NH\}_y]{\cdot}zG$, has been investigated for benzene (B), toluene (T), ethylbenzene (E), o- (O), m- (M), and p-xylene (P) isomers as the aromatic guest molecules. From the binary, ternary and quarternary guest mixtures of E and xylene isomer (X), the order of inclusion selectivity in the host complex is O>E>P>M. From the binary to quinary BTX mixtures, the order of preference in the complex is seen to be B>T>O${\gg}$P>M.

• KSBB Journal
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• v.10 no.2
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• pp.149-158
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• 1995

The capacity of inclusion complex formation between ${\alpha}$-, ${\beta}$-, ${\gamma}$-cyclodextrins(CDs) and various compounds, such as pH indicators, biloslalns, glycoside, amino acid, and fatty acids, was compared. Fatty acid was identified as the most suitable ligand for fractionation of CDs in terms of capacity and selectivity. The effects of complex formation conditions, such as, mixing ratio of CD and fatty acid, pH, ionic strength, and temperature, on the capacity of fatty acrid-CD complex was also investigated. The carbon number of fatty acids was identified as the most significant factor determining the capacity and selectivity of inclusion complex formation of CDs. Capric acid(C10) and palmitic acid(C16) showed high specificity for ${\alpha}$- and ${\beta}$-CDs, respectively. Under the optimal conditions, the molar ratio of complex formed was found to be 1.0:2.6 for ${\alpha}$-CD/capric acid and 1.0:1.9 for ${\beta}$-CD/palmitic acid. X-ray diffraction and infrared spectrum of the formed inclusion complex were analyzed. The changes of enthalpy($\Delta$H) of the inclusion complex formation reaction was evaluated by differential scanning calorimetry, showed that the reaction was endothermic.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.451-460
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• 2015

An enantioselective recognition of D- and L-tryptophan (Trp)-b-cyclodextrin (CD) inclusion complex was performed using electrochemical and FT-Raman spectroscopic analysis. From the electrochemical analysis, the selectivity coefficient ($K_{DL}$) of b-CD inclusion complexes was found higher than that of the D- and L-Trp in phosphate buffered saline (PBS, pH=7.0) solution. The percentage of enantioselectivity ($I_{%{ee}}$) for peak current of D-Trp-b-CD inclusion complexes was observed higher than that of L-Trp-b-CD inclusion complexes in PBS solution. From Raman spectroscopy, chemical shift difference (D, $cm^{-1}$) for the C=C stretch, ring vibration, and ring breathing of D-Try-b-CD inclusion complex were observed higher than that of L-Trp-b-CD inclusion complex. The electrochemical and Raman spectroscopic analyses were found very useful for chiral detection of racemic amino acid in the presence of b-CD.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1509-1516
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• 2012

Nano-assisted inclusion separation of alkali metals from basic solutions was reported by inclusion-facilitated emulsion liquid membrane process. The novelty of this study is application of nano-baskets of calixarene in the selective and efficient separation of alkali metals as both the carrier and the surfactant. For this aim, four derivatives of $p-tert-calix$[4]arene bearing different sulfonamide moieties were synthesized and their inclusion-extraction parameters were optimized including the calixarene scaffold $\mathbf{3}$ (4 wt %) as the carrier/demulsifier, the commercial kerosene as diluent in membrane, sulphonic acid (0.2 M) and ammonium carbonate (0.4 M) as the strip and the feed phases, the phase and the treat ratios of 0.8 and 0.3, mixing speed (300 rpm), and initial solute concentration (100 mg/L). The selectivity of membrane over more than ten interfering cations was examined and the results reveled that under the optimized operating condition, the degree of inclusion-extraction of alkali metals was as high as 98-99%.

• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.487-492
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• 2007

Using the selective host-guest inclusion of $G_2$[naphthalene disulfonate], the structural isomers of 1,2-dibromobenzene and 1,3-dibromobenzene were separated. As such, 1,3-dibromobenzene was selectively included as guest into the host framework in mixture isomers over 30% fraction of 1,3- dibromobenzene ($X_{1,3-DBB}=0.3$) whereas 1,2-dibromobenzene as guest was selective to the inclusion below $X_{1,3-DBB}=0.3$. This was due to the selectivity of host framework toward the guest molecules playing a role of template to the host framework. From the powder pattern XRD of inclusion compounds crystallized in pure isomer and mixture solutions, the template roles of guest molecules to the host framework were confirmed. Using the DSC, it was found that the more energy was required to release 1,3-dibromobenzene of guest from the host framework than 1,2-dibromobenzene due to the higher thermal stability. The thermal stability of the $G_2NDS$-1,3-dibromobenzene inclusion compound was consistent with the high selectivity of 1,3- dibromobenzene to the host framework in broad range of fraction in the isomer mixture

• Membrane and Water Treatment
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• v.3 no.2
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• pp.123-131
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• 2012

This study investigated the extraction and stripping performance of PIMs consisting of PVC and Aliquat 336. Extraction and stripping of three representative heavy metals - namely $Cd^{2+}$, $Cu^{2+}$, and $Zn^{2+}$ - by the synthesized membranes were evaluated as a function of sodium chloride concentration and under different stripping solutions (0.01 M $HNO_3$, Milli-Q water, 0.01 M HCl and 0.01 M NaOH), respectively. Results reported here indicate that the formation of negatively charged metal chloride complex species was responsible for the extraction of the target metal to PIMs. Experimental results and thermodynamic modeling of the speciation of chloro metal complexes further confirm that the extraction selectivity between $Cd^{2+}$, $Cu^{2+}$ and $Zn^{2+}$ can be controlled by regulating the chloride concentration of the feed solution. An acidic solution without any chloride was the most effective stripping solution, followed by Milli-Q water, and a diluted hydrochloric acid solution. On the other hand, the stripping of metals from PIMs did not occur when a basic stripping solution was used.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.953-958
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• 2008

A novel anthraquinone diamino-bridged bis($\beta$ -cyclodextrin) 2 was synthesized. The inclusion complexation behaviors of the native $\beta$ -cyclodextrin 1 and the novel bis($\beta$ -cyclodextrin) 2 with guests, such as acridine red (AR), neutral red (NR), ammonium 8-anilino-1-naphthalenesulfonate (ANS), sodium 2-(p-toluidinyl) naphthalenesulfonate (TNS) and rhodamine B (RhB) were investigation by fluorescence, circular dichroism and 2D NMR spectroscopy. The spectral titrations were performed in phosphate buffer (pH 7.20) at 25 ${^{\circ}C}$ to give the complex stability constants (Ks) and Gibbs free energy changes (−${\Delta}G^0$) for the stoichiometric 1:1 inclusion complexation of host 1 and 2 with guests. The results indicated that the novel bis($\beta$ -cyclodextrin) 2 greatly enhanced the original binding affinity of the native $\beta$ -cyclodextrin 1. Typically, bis($\beta$ -cyclodextrin) 2 showed the highest binding constant towards ANS up to 34.8 times higher than that of 1. The 2D NMR spectra of bis($\beta$ -cyclodextrin) 2 with RhB and TNS were performed to confirm the binding mode. The increased binding affinity and molecular selectivity of guests by bis($\beta$ -cyclodextrin) 2 were discussed from the viewpoint of the size/shape-fit concept and multipoint recognition mechanism.

• Macromolecular Research
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• v.17 no.10
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• pp.729-733
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• 2009

Solution casting films of sulfonated poly[styrene-b-(ethylene-r-butylene)-b-styrene] copolymer (sSEBS)-based composite membranes that contained different amounts of organic, nanorod-shaped polyrotaxane were annealed at various temperatures for 1 h. The films' properties were characterized with respect to their use as polymer electrolyte membranes in direct methanol fuel cells (DMFCs). Different aspect ratios of polyrotaxane were prepared using the inclusion-complex reaction between $\alpha$-cyclodextrin and poly(ethylene glycol). The presence of the organic polyrotaxane inside the membrane changed the morphology during the membrane preparation and reduced the transport of methanol. The conductivity and methanol permeability of the composite membranes decreased with increasing polyrotaxane content, while the annealing temperature increased. All of the sSEBS-based, polyrotaxane composite membranes annealed at $140^{\circ}C$ showed a higher selectivity parameter, suggesting their potential usage for DMFCs.

• Macromolecular Research
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• v.14 no.2
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• pp.214-219
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• 2006

Cast Nafion-based composite membranes containing different amounts of organic, nanorod-shaped polyrotaxane were prepared and characterized, with the aim of improving the properties of polymer electrolyte membranes for direct methanol fuel cell applications. Polyrotaxane was prepared using the inclusion-complex reaction between ${\alpha}$-cyclodextrin and poly(ethylene glycol) (PEG) of different molecular weights. The addition of polyrotaxane to Nafion changed the morphology and reduced the crystallinity. The conductivity of the composite membranes increased with increasing polyrotaxane content up to 5 wt%, but then decreased at higher polyrotaxane contents. Well-dispersed, organic polyrotaxane inside the membrane can provide a tortuous path for the transport of methanol, as the methanol permeability depends on the aspect ratio of polyrotaxane, which is controlled by the molecular weight of PEG. All of the Nafion-based, polyrotaxane composite membranes showed a higher selectivity parameter than the commercial Nafion films did.

• YAKHAK HOEJI
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• v.47 no.4
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• pp.200-205
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• 2003

The stability constants for the inclusion complexes between carboxymethyl-$\beta$-cyclodextrin (CM-$\beta$-CD) and five $\beta$-blockers, such as atenolol (ATE), bisoprolol (BIS), metoprolol (MET), pindolol (PIN) and propranolol (PRO) were determined by capillary electrophoresis. The magnitude of stability was decreased as following order; PRO＞MET＞BIS＞ATE＞PIN. Among them PRO showed the highest affinity towards CM-$\beta$-CD with stability constants of 383 and 371 $M^{-l}$ for (R)- and (S)-enantiomer, respectively. PIN enantiomers showed the lowest stability towards CM-$\beta$-CD, while the selectivity between (R)- and (S)-enantiomer was higher than any other tested $\beta$-blocker.r.