It was found that in a triply-capped calixarene (1) and doubly-bridged calixarene (2a and 2b) with a closed ionophoric cavity the Cs+ complexation occurs very slowly in a human time-scale and can be followed by a conventional spectroscopic method. The unusual behavior has enabled us to determine their kinetic activation parameters for both the forward and the reverse reaction. The results established that being different from the concept believed so far, the Cs+ complexation is heavily governed by the entropy term but not by the enthalpy term.
All Science Journal Classification (ASJC) codes
- Drug Discovery
- Organic Chemistry