Guest-enhanced kinetic stability of hydrogen-bonded dimeric capsules of tetraurea Calix
Inclusion complexes of self-assembled molecular dimers composed of two tetratolylurea calix[4]arenes show strongly different kinetic stability for different guests. In cyclohexane-d(12), half-life times for the exchange of a guest against the solvent vary from 2.9 h (chloroform) through 20 h (benzene) and 74 h (fluorobenzene) to 78 days for cyclohexane. This demonstrates that the kinetic stability of such a dimer can be strongly increased by the choice of a suitable guest.
Vysotsky
MO
Fachbereich Chemie und Pharmazie, Abteilung Lehramt Chemie, Johannes Gutenberg-Universitat, Duesbergweg 10-14, D-55099 Mainz, Germany.
Bohmer
V