Operation Mechanism of a Molecular Machine Revealed Using Time-Resolved Vibrational Spectroscopy

Matthijs R. Panman, Pavol Bodis, Daniel J. Shaw, Bert H. Bakker, Arthur C. Newton, Euan R. Kay, Albert M. Brouwer, Wybren Jan Buma, David A. Leigh, Sander Woutersen

Research output: Contribution to journalArticlepeer-review

Abstract

Rotaxanes comprise macrocycles that can shuttle between docking stations along an axle. We explored the nanosecond shuttling mechanism by reversing the relative binding affinities of two stations through ultraviolet-induced transient reduction. We monitored the ensuing changes in the CO-stretching bands of the two stations and the shuttling macrocycle by means of an infrared probing pulse. Because hydrogen-bond scission and formation at the initial and final stations led to well-resolved changes in the respective CO-stretch frequencies, the departure and arrival of the macrocycle could be observed separately. We found that the shuttling involves two steps: thermally driven escape from the initial station, followed by rapid motion along the track ending either at the initial or final station. By varying the track's length, we found that the rapid motion approximates a biased one-dimensional random walk. However, surprisingly, the direction of the overall motion is opposite that of the bias.

Original languageEnglish
Pages (from-to)1255-1258
Number of pages4
JournalScience
Volume328
Issue number5983
DOIs
Publication statusPublished - 4 Jun 2010

Fingerprint

Dive into the research topics of 'Operation Mechanism of a Molecular Machine Revealed Using Time-Resolved Vibrational Spectroscopy'. Together they form a unique fingerprint.

Cite this