• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.620-622
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• 2008

A new thiacalix[4]arene diamide (TCAm) has been prepared and its electrochemical property and complexation behavior toward various metal ions have been investigated by voltammetry. p-tert-Butylthiacalix[4]arene diamide (TCAm) exhibited selectivity toward Sr2+ ion over alkali, alkaline earth and transition metal ions while conventional calix[4]arene diamides showed selective binding property with Ca2+ ion. This is probably due to the bigger size of thiacalix[4]arene than those of calix[4]arene.

• Proceeding of EDISON Challenge
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• 2013.04a
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• pp.77-88
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• 2013

The computational study on the fluoride ion binding with bis(bora)calix[4]arene has been performed using density functional theory and ONIOM model. The computed structure and fluorescent behavior of bis(bora)calix[4]arene was corresponded to experiment value. The binding energy for fluoride anion is computed to be 28.05kJ/mol in the chloroform solution. We also predicted that this sensing mechanism is only valid for fluoride ion in halogens. By analyzing molecular orbitals, binding with fluoride ion reduces energy differences between HOMO and LUMO, which leads to fluorescent sensing.

• Bulletin of the Korean Chemical Society
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• v.22 no.4
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• pp.409-412
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• 2001

Poly(p-tert-butyltrimethoxymonopropyloxycalix[4]arene-methylsiloxane) (TBCX-MS) has been prepared and used as a stationary phase in isothermal capillary gas chromatographic separation of some positional isomers. Retention factors (k) and separatio n factors $(\alpha)$ for the isomers were measured and compared with those on poly(p-tert-butyl-dimethoxydipropyloxycalix[4]arene-tetramethyldisiloxane) (TBCX-TMDS), poly(dimethoxydipropyloxycalix[4]arenetetramethyl-disiloxane) (CX-TMDS). Most of the isomers investigated are well resolved on TBCX-MS. Retention of all the compounds decreases on the three phases in the order, TBCX-TMDS ${\geq}$ TBCX-MS > CX-TMDS. Similar retention values on TBCX-TMDS and TBCX-MS seem to indicate that retention property of the two phases is not significantly affected by the spatial position of the calixarene moiety.

• Bulletin of the Korean Chemical Society
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• v.18 no.4
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• pp.409-415
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• 1997

Several calixarene derivatives of 5,11,17,23-tetra-tert-butyl-25-(3,5-dinitrobenzoyloxy)-26,27,28-trihydroxycalix[4]arene 2 were synthesized by the reaction of 2 with several acyl and alkylating agents in the presence of base such as pyridine and K2CO3 in THF. Acylation of monobenzoylated p-tert-butylcalix[4]arene 2 yielded their corresponding 1,3-diacylated calix[4]arenes 3a-3g. On the other hand, alkylation of 2 produced a variety calix[4]arene derivatives such as 1,2- and 1,3-disubstituted calix[4]arenes 4a-4c, 4e-4f, or 1,2,4-trisubstituted calix[4]arene 4d. 1,2-Disubstituted calix[4]arenes are chiral. All derivatives exist as a cone conformation based on NMR studies.

• Bulletin of the Korean Chemical Society
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• v.12 no.5
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• pp.525-529
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• 1991

A simple route is described for the selective functionalization of calixarene at the para positions of phenyl rings. Calix[4]arene tetraacetate 2, obtained from the treatment of calix[4]arene with acetic anhydride, undergoes Fries rearrangement to yield the diametrically para substituted p-diacetylcalix[4]arene 3 in 80% yield. The crystal and molecular strucutre has been determined by X-ray diffraction method. The crystals are orthorhombic, space group Pna21, with a = 11.121 (3), b = 10.374 (3), c = 21.690 (6) $\AA$ and Z = 4. The structure was solved by direct method and refined by full-matrix least-squares methods to final R of 0.036 for 1795 observed reflections. Each hydroxyl hydrogen atom is disordered over two positions. The macrocycle exists in the cone conformation which is determined by the strong circular intramolecular flip-flop type hydrogen bonds of phenolic OH, while crystal packing effects of the diametrically para-acetyl substituents seem to be responsible for the distortion of the cone conformation.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.3979-3990
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• 2011

Eight ionizable nano-baskets of cone 25,26-di(carboxymethoxy)calix[4]arene-crown-3,4,5,6 were synthesized and were verified by $^1H$ and $^{13}C$ NMR spectroscopy, IR spectroscopy and elemental analysis. The competitive solvent extractions of alkali and alkaline earth metal cations were studied using such nano-baskets. The novelty of this study is including three binding units of calixarene's bowl, crown ether's ring and electron-donor ionizable moieties in a unique scaffold to assess the binding tendency towards the cations. The objective of this work is to study the extraction efficiency, selectivity and $pH_{1/2}$ of such complexes. The result of solvent extraction experiments indicated that these compounds were effective extractants of alkali and alkaline earth metal cations. Their selectivities were greatly influenced by the acidity of solution and the conformations of the calixcrown. One conformer was selective to $Na^+$ in pH ${\geq}$ 4, while the other was highly selective to $Ba^{2+}$ in pH 6 and upper.

• Korean Journal of Crystallography
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• v.4 no.1
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• pp.25-35
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• 1993

Tetra-tert-butyl-tetrapropionycalix (4) arena (C56H7208) is Triclinic, space group Pl, with a=13.664(5), b=17.585(5), c=12.863(2)A, a=109.33(2), B=111.97(2), γ=76.45(3) ˚, Z=2, V=2684.08A3, D, =1.152g/cm3, Dm=1.15g/cm3. The intensity data were collected on an Enraf-Nonius CAD-4 Diffractometer with a graphite monochromated Mo-Ka radiation. The structure was solved by direct methods and refined by leastsquares methods. The final R factor was 0.084 for 2561 observed reflections. The configuration of the molecule from the X-ray crystallographic investigation has the partial cone conformation, three tort-butylphenyls are down and a tort-butylphenyl is up. Three propionyloxy groups direct toward the exterior of the macrocycle cavity.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.819-822
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• 2004

Protonation constants of calix[4]-cyclen-benzo-crown-6, L in 1X$10^{-2}$ M $Bu_4NCF_3SO_3$ in 40% $CH_2Cl_2/CH_3OH$ at $25^{\circ}C$ determined by potentiometric titration are log $K_1$ = 10.91, log $K_2$ = 10.30, log $K_3$ = 6.24 and log $K_4$ = 2.55. Stability constants for the receptor L complexes with Cu(II) and Zn(II) in 1X$10^{-2}$ M $Bu_4NCF_3SO_3$ in 40% $CH_2Cl_2/CH_3OH$ at $25^{\circ}C$ were determined by UV-VIS spectrometric titration. Stability constants of the CuL and ZnL complexes as log $\beta$ are 4.37 and 3.45, respectively. Stabilization energies for protonations of receptor L, derived from ab initio Hartree-Fock method with 6-31G basis set, are ${\Delta}E_1$ = -290.1, ${\Delta}E_2$ = -205.0, ${\Delta}E_3$ = -124.9 and ${\Delta}E_4$ = -26.9 kcal/mol and complexation energy of ZnL complex is -370.3 kcal/mol.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.791-794
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• 2007

A new azocalix[4]arene, 5,14,17,23-tetra[(2-benzoic acid)(azo)phenyl] calix[4]arene (2), has been prepared by hydrolysis of its ester derivative and characterized by 1H NMR, IR, UV-Vis spectroscopy and elemental analysis. Based on UV spectral changes, we found that 2 exhibits Pb2+ ion selectivity. In basic media, Pb2+ forms a 1:1 complex with the ligand. Beer's law is obeyed in the range of 2.0 × 10?6 ? 2.4 × 10?5 mol L?1 of Pb2+. The molar absorptivity (ε ) of 2-Pb2+ complex is 1.89 × 104 L mol?1 cm?1 at 440 nm, and the detection limit is 1.6 × 10?6 mol L?1.

• Korean Journal of Crystallography
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• v.6 no.2
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• pp.80-87
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• 1995

The structure of Tetrapropionyloxycalix[4]arene(C40H40O8) has been studied by X-ray diffraction method. The crystal is monoclinic a=13.921(3), b=13.552(2), c=19.840(5)Å, β=110.38(2)°, Z=4 T=297K, Dc=1.23gcm-3, F(000)=1376, Systematic absences : hkl none, h0l : h+l=2n, 0k0: k=2n define space group P21/n. The structure was solved by direct method and refined by full-matrix least-squares methods to final R of 0.06 for 2514 observed reflections. The macrocycle exists in partial cone conformation. Three propionyl groups direct toward the exterior of the macrocycle cavity.