• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.589-594
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• 2009

We have performed DFT B3LYP/6-31G(d,p) calculations to investigate the complexation behaviors of the ethyl ester derivative of p-tert-butylcalix[6]arene (1) toward a variety of alkylammonium ions. We have studied the binding sites of these host-guest complexes focusing on the p-tert-butylcalix[6]arene pocket (endo) of 1. The smaller alkylammonium cations have the better complexation efficiency than the bulkier alkylammonium ions with the p-tert-butylcalix[6]aryl ester. The hydrogen-bonding of N-H$\ldots$O is one of the important factors for the complexation behavior of the p-tert-butylcalix[6]aryl ester, in addition to the NH-aromatic π, CH-aromatic π and electrostatic interactions, and the steric hindrance of alkylammonium cation. The hydrogen-bonded distances and angles of N-H$\ldots$O are reported for the complexes of the p-tert-butylcalix[6]aryl ester with various alkylammonium ions.

• Journal of the Korean Chemical Society
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• v.38 no.7
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• pp.509-515
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• 1994

The interactions of 11 kinds of primary and secondary alkylammonium ions with cyclic (12C4, 15C5, 18C6, DT18C6 and DA18C6) and acyclic$(Q_2O_5)$ polyethers were investigated by NMR titration and conductometry. All of the alkylammonium ions under investigation form the relatively stable 1 : 1 complexes with crown ethers and acyclic polyether by H-bond. The interactions of alkylammonium ions with analogeous hosts having different size were in the order of 18C6 > 15C5 > 12C4, and the strengthes of donor atoms toward the alkylammonium ions were in the order of N > O > S. 18C6 forms more favorable interactions with primary alkylammonium ions than secondary alkylammonium ions, otherwise DA18C6 shows the opposite behaviors. The stability constants for complexations of 18C6 with the alkylammonium ions were determined conductometrically in methanol at 25$^{\circ}C$. The major factors affecting the stability of complexes were the type of alkylammonium ions, the length of alkyl-chain and the steric hindrance due to the structure of alkyl groups on complexation.

• Journal of the Korean Ceramic Society
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• v.22 no.4
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• pp.3-8
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• 1985

The layer charge densities and interlayer C. E. C(cation exchange capacity) of ten mica-type aluminosilicates from Yong-il Pohang-prefacture were determined by n-alkylammonium method which is based on the mo-nolayer-doubelelayer structural transition of ni-alkylammonium ion in interlayer space of the layered silcates. The upper and lower limits of layer charge and interlyer C, E, C estimated were about 0.25~0.36 eq/(Si, $Al)_4$ O10 and 69~99meq/100g, respectively.

• Bulletin of the Korean Chemical Society
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• v.28 no.4
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• pp.596-600
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• 2007

The structures and energies of p-tert-butylcalix[5]crown-6-ether (1) and its alkylammonium complexes have been calculated by DFT B3LYP/6-31G(d,p) method. We have studied the binding sites of these host-guest complexes focusing on the p-tert-butylcalix[5]arene pocket (endo) or the crown-6-ether moiety (exo) of 1. The smaller alkylammonium cations have the better complexation efficiency with p-tert-butylcalix[5]crown-6- ether than the bulkier alkylammonium ions. For the sec- and tert-butylammonium ions, the hydrogen-bond distances of the exo-complexes are shorter, therefore, stronger than the endo-cases. This DFT calculated result is in parallel with the trend of the experimental association constants of the branched butylammonium ions.

• Journal of the Korean Ceramic Society
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• v.22 no.6
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• pp.53-57
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• 1985

Korean montmorillonite from Youngil district was characterized by Alkylammonium derivatives. This method was very sensitive to the basal plane spacing d and the charge in the layer charge. The result include the values of average layer charge, charge distribution, equivalent area. interlayer cationic exchange capacity (C, E, C) and total C. E. C.

• Bulletin of the Korean Chemical Society
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• v.18 no.1
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• pp.86-91
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• 1997

Complexation of primary alkylammonium ions by 1, 3-distal calix[4]arene diesters was studied by NMR spectroscopy. The guest alkylammonium ions are found to bind mainly to the two ester moieties and are oriented outward with respect to the cone cavity of the host, forming exo-type complexes unlike the case of alkylammonium-calix[6]arene systems. Measurement of T1 also revealed that the primary binding site is the two ester moities and phenolic OH groups. The temperature dependence of the chemical shifts of phenolic OH protons in these diesters correlates with the basicity of the solvent moderately well and the temperature coefficients of their chemical shifts are found to significantly decrease upon complexation with propylammonium ion.

• Bulletin of the Korean Chemical Society
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• v.19 no.2
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• pp.207-211
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• 1998

Potentiometric characteristics of DOS plasticized PVC-based membranes containing upper-rim calix[4]crown neutral carrier to various metal cations and protonated alkylamines have been examined. Although the calix[4]crown-based membrane electrodes exhibited substantial emf responses to alkali and alkaline earth metal cations, their high detection limits (- log[Cs+]=4.5) and sub-Nernstian response slopes (48 mV/pCs+) to the most selective cation, cesium, indicate that the metal cation complexing ability of calix[4]crown is much weaker than that of macrocyclic crown ethers. However, the calix[4]crown-based membrane electrodes exhibited near-Nernstian response slopes (56 mV/decade for hexylNH3+) with low detection limits (log[hexylNH3+]= - 6.7) to most alkylammonium ions compared to those of blank (DOS plasticized PVC membrane with no ionophore) or crown ether-based membranes. While the selectivity patterns of blank and crown ether-based membranes are determined primarily by the lipophilicity of alkylammonium ions, the membranes doped with calix[4]crown ionophore could effectively discriminate the steric shapes of nonpolar alkyl groups of alkylammonium ions.

• Journal of the Korean Chemical Society
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• v.49 no.1
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• pp.112-116
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• 2005

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.2097-2100
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• 2011

• Bulletin of the Korean Chemical Society
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• v.21 no.11
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• pp.1119-1124
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• 2000

$\beta-Cyclodextrin$ derivatives connected with diaza-18-crown-6 through flexible bridges (R) at the secondary face 1a-c (1a: R = $-(CH_2)4-;$ 1b: R = $-CH_2CH_2OCH_2CH2-;$ 1c: R = $-(CH_2)8-)$ have been prepared. The associa tion constants of 1 with (2-naphthoxy)alkylammonium ions (2a: alkyl = butyl; 2b: alkyl = octyl) were determined by induced circular dichroism (ICD) spectroscopy and it was found that the derivatization of $\beta-CD$ with the diazacrown resulted in enhanced binding with 2, compared to the native $\beta-CD.$ ICD Characteristics of the host-guest complexes indicate that a part of the alkylammonium moiety of 2 is protruded from the secondary side of the $\beta-CD$ cavity, and the guest molecules 2a and 2b move to the secondary and primary side, respectively, to make the binding of the ammonium group with the diaza-18-crown-6 moiety more feasible. The energy accompanied by the relocation of the guest molecules inside $\beta-CD$ moiety is compensated by the interaction energy between the ammonium ion and diazacrown ether.