Double Molecular Photoswitch Driven by Light and Collisions

Bull, James N., Scholz, Michael S., Carrascosa, Eduardo, Da Silva, Gabriel and Bieske, Evan J. (2018) Double Molecular Photoswitch Driven by Light and Collisions. Physical Review Letters, 120 (22). ISSN 0031-9007

Full text not available from this repository. (Request a copy)


The shapes of many molecules can be transformed by light or heat. Here we investigate collision- and photon-induced interconversions of EE, EZ, and ZZ isomers of the isolated Congo red (CR) dianion, a double molecular switch containing two NN azo groups, each of which can have the E or Z configuration. We find that collisional activation of CR dianions drives a one-way ZZ→EZ→EE cascade towards the lowest-energy isomer, whereas the absorption of a single photon over the 270-600 nm range can switch either azo group from E to Z or Z to E, driving the CR dianion to lower- or higher-energy forms. The experimental results, which are interpreted with the aid of calculated statistical isomerization rates, indicate that photoisomerization of CR in the gas phase involves a passage through conical intersection seams linking the excited and ground state potential energy surfaces rather than through isomerization on the ground state potential energy surface following internal conversion.

Item Type: Article
Uncontrolled Keywords: physics and astronomy(all) ,/dk/atira/pure/subjectarea/asjc/3100
Faculty \ School: Faculty of Science > School of Chemistry
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 28 Feb 2019 16:30
Last Modified: 18 Sep 2020 00:20
DOI: 10.1103/PhysRevLett.120.223002

Actions (login required)

View Item View Item