ORGN 349 |
| Emilio M. Pérez and David A. Leigh. School of Chemistry, University of Edinburgh, The King's Buildings, West Mains Road, EH9 3JJ Edinburgh, United Kingdom |
| Although various methods for switching the positions of macrocycles in bistable rotaxane-based molecular shuttles have been developed, exploiting such movements to trigger property changes has thus far received little attention. Here we describe two of the first examples of property changes achieved through controlled translational motion in a rotaxane; novel types of fluorescence (Z/E-1) and CD switches in which light-induced translation of the macrocycle along the thread switches ‘on’ and ‘off’ different types of optical response. Indeed, our work suggests that when considering the architecture of a [2]rotaxane-based molecular shuttle, it should be feasible to switch ‘on’ and ‘off’ any distance-dependent molecular property! We also report the chance discovery of the first tristable molecular shuttle; a remarkable entropy-driven system where, starting with the ring on the central station, it can be made to move in one direction by irradiation with light and in the other simply by raising the temperature. Together these results significantly extend the prospects for designing practical molecular machines.
|
|
Materials, Devices, and Switches
1:00 PM-5:00 PM, Tuesday, August 24, 2004 Pennsylvania Convention Center -- 201B, Oral
Division of Organic Chemistry |
