Kinetics and Thermodynamics of Hexameric Capsule Formation
- 11 February 2004
- journal article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 126 (9), 2939-2943
- https://doi.org/10.1021/ja037035u
Abstract
Resorcinarene 1b forms a hexameric assembly in water-saturated CDCl(3) that encapsulates one tetraalkylammonium salt (2(+)Br(-)). The remaining space is occupied by coencapsulated solvent molecules. A maximum of three and minimum of one CHCl(3) molecule were found inside of capsules with tetrapropyl- and tetraheptylammonium bromide, respectively. The encapsulation of the salt is endothermic and entropically favored by the liberation of the solvent molecules. The stabilities of the encapsulation complexes and the rates of guest exchange decrease for larger cations. The higher activation barriers for in/out exchange of the larger guests suggest tight conformational restraints in the transition state. It is likely that complete dissociation of one resorcinarene molecule is necessary for the exchange of the alkylammonium salts.Keywords
This publication has 20 references indexed in Scilit:
- Assembly of Resorcinarene Capsules in Wet SolventsJournal of the American Chemical Society, 2003
- The Role of Water Molecules in a Resorcinarene Capsule As Probed by NMR Diffusion MeasurementsOrganic Letters, 2002
- Nanoscale Molecular ContainersBulletin of the Chemical Society of Japan, 2002
- Dynamic NMR studies of supramolecular complexesProgress in Nuclear Magnetic Resonance Spectroscopy, 2001
- Estimating the CO 2 Uptake in EuropeScience, 1998
- Dynamics of Assembly and Guest Exchange in the Tennis BallJournal of the American Chemical Society, 1998
- NMR Studies of the Reversible Dimerization and Guest Exchange Processes of Tetra Urea Calix[4]arenes Using a Derivative with Lower SymmetryJournal of the American Chemical Society, 1997
- Entropically driven binding in a self-assembling molecular capsuleNature, 1996
- Application of two-dimensional NMR to kinetics of chemical exchangeChemical Reviews, 1990
- Host-guest complexation. 48. Octol building blocks for cavitands and carcerandsThe Journal of Organic Chemistry, 1989