Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10393299 | Thermochimica Acta | 2005 | 4 Pages |
Abstract
Calorimetric titration experiments have been performed in pH 2.0 and 7.2 phosphate buffer solutions at 298.15 K to calculate the complex stability constants (KS) and thermodynamic parameters (ÎG°, ÎH°, and TÎS°) for the stoichiometric 1:1 inclusion complexation of water-soluble calix[4]arene tetrasulfonate (CAS) and thiacalix[4]arene tetrasulfonate (TCAS) with some diazacycloalkane guests, i.e. piperazine (1), homopiperazine (2) and 1,5-diazacyclooctane (3). The results indicated that complexes of CAS and TCAS with diazacycloalkane guests were enthalpy-stabilized, and an acidic environment was more favorable to host-guest complexation than a neutral one. CAS forms more stable complexes with guest molecules than TCAS due to the more favorable enthalpic gain.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
Yu Liu, En-Cui Yang, Yong Chen,