Probing the structure of a rotaxane with two-dimensional infrared spectroscopy
PNAS , Volume 102 p. 13378- 13382
Femtosecond 2D-IR spectroscopy has been used to study the structure of a rotaxane composed of a benzylic amide macrocycle that is mechanically interlocked onto a succinamide-based thread. Both the macrocycle and the thread contain carbonyl groups, and by determining the coupling between the stretching modes of these groups from the cross-peaks in the 2D-IR spectrum, the structure of the macrocycle-thread system has been probed. Our results demonstrate that 2D-IR spectroscopy can be used to observe structural changes in molecular devices on a picosecond time scale.