Inclusion compounds of a diol host with xylidines: controlled stoichiometries.
The diol host, 1,1'-bis-(4-hydroxyphenyl)cyclohexane (DHPC) and a number of xylidine isomers as guests formed a series of inclusion compounds that gave rise to various host:guest ratios controlled by crystallization temperatures. For the host DHPC with a particular xylidine isomer, the number of guests included generally decreases as the crystallization temperature increases. The crystal structures of these host-guest compounds were elucidated using single-crystal X-ray diffraction. Their thermal stabilities were characterized by TG and DSC analysis. The selectivity of enclathration by the host was measured by carrying out a series of competition experiments. The kinetics of guest decomposition were studied using isothermal and non-isothermal methods and reconciled with the crystal structures.
Introduction to Thermal Analysis: Techniques and applications
1. Introduction. 2. Thermal Events. 3. Thermogravimetry (TG). 4. Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). 5. Thermoptometry. 6. Thermomechanometry. 7. Combination of Thermal Analysis Techniques. 8. Evolved Gas Analysis (EGA). 9. Less-Common Techniques. 10. Reaction Kinetics from Thermal Analysis. 11. Purity Determination Using DSC. 12. Conclusions. Appendices. A: Literature. B: Major Suppliers of Thermal Analysis Equipment. C: Data Processing in Thermal Analysis. D: Introductory Experiments. E: Example Examination Questions. Explanation of the Symbols Used in the Text. Index.
Inclusion of organic vapours by crystalline hosts. Chemical-sensitive coatings for sensor applications
Abstract Solid inclusion hosts, such as derivatives of bis-fluorenyl (1, 2) and maleic acid (3), can include organic solvent vapour molecules such as acetone, cyclohexanone, methanol, ethanol, 1-butanol and dioxane to form stoichiometric inclusion complexes. Due to their ability to be used as gas-sensing layers, the absorption and desorption of acetone by crystalline host 1 is on-line monitored by a recording balance. For sensitivity improvement hosts 1 and 3 are coated onto the surface of a quartz crystal, the indicating device of the quartz microbalance. In the presence of various saturated vapour atmospheres we obtained reversible and reproducible signals within a short response time. Stoichiometrics of sorptive clathrate formations with 1–3 are determined by weighing. By differential scanning calorimetry (DSC) temperature dependence and enthalpies of guest desorption from host 1 can be determined, thus indicating weak host-guest interactions.