• 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.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.289-292
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• 2014

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.100-104
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• 2011

The structures of the conformers for 1,3-di-t-butyl-2,4-dinitro-tetramethoxysulfonylcalix[4]arene (1) and 1,2-di-t-butyl-3,4-dinitro-tetramethoxysulfonylcalix[4]arene (2) were optimized using DFT BLYP and mPW1PW91/6-31G(d,p) (hybrid HF-DF) calculation methods. We have analyzed the total electronic and Gibbs free energies and the differences between the various conformations (cone, partial-cone (PC), 1,2-alternate, and 1,3-alternate) of 1 and 2. For both compounds, the 1,3-alternate (1,3-A) conformers were calculated to be the most stable, which correlate very well with the experimental results. The orderings of the relative stability of 1 and 2 that resulted from the mPW1PW91/6-31G(d,p) calculations are the following: 1: 1,3-A (syn) > PC (syn) > PC (anti) > 1,2-A (anti) > CONE (syn); 2: 1,3-A (anti) > PC (anti) > PC (syn) > 1,2-A (anti) > 1,2-A (syn) > CONE (syn). The BLYP/6-31G(d) calculated IR spectra of the most stable 1,3-A conformers of 1 and 2 are compared.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2229-2237
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• 2012

The two chelates based on calix[4]arene and thiacalix[4]arene have been synthesized and used as neutral ionophores for preparing PVC based membrane sensor selective to $Ho^{3+}$ ion. The addition of potassium tetrakis(4-chlorophenyl)borate (KTpClPB) and various plasticizers, viz., NDPE, o-NPOE, DOP, TEP and DOS have been found to improve significantly the performance of the sensors. The best performance was obtained with the sensor no. 6 having membrane of $L_2$ with composition (w/w) ionophore (2%): KTpClPB (4%): PVC (37%): NDPE (57%). This sensor exhibits Nernatian response with slope $21.10{\pm}0.3mV/decade$ of activity in the concentration range $3.0{\times}10^{-8}-1.0{\times}10^{-2}M\;Ho^{3+}\;ion$, with a detection limit of $1.0{\times}10^{-8}M$. The proposed sensor performs satisfactorily over a wide pH range of 2.8-10, with a fast response time (5 s). The sensor was also found to work successfully in partially non-aqueous media up to 25% (v/v) content of methanol, ethanol and acetonitrile, and can be used for a period of 4 months without any significant drift in potential. The electrode was also used for the determination of $Ho^{3+}$ ions in synthetic mixtures of different ions and the determination of the arsenate ion in different water samples.