Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 16, 2010 | public
Journal Article

Ultrafast excited-state dynamics of ferrocene-bridge-acceptor system

Abstract

We employed both femtosecond fluorescence up-conversion and transient absorption techniques with ~150 fs time resolution to study the excited-state deactivation process of an intra-molecular charge transfer model compound, 4-(ferrocen-1-yl)benzylidene-malononitrile (Fc-ph-DCV), which consists of ferrocene (Fc) unit as an electron donor, dicyanovinly (DCV) as an electron acceptor and phenyl (ph) ring as the central bridge. The results showed that after photoexcitation into the higher excited S_2 state, ultrafast internal conversion into S_1 takes place. The rate of S_2 → S_1 internal conversion is markedly faster (with a typical time of 120 fs ± 20 fs) than the diffusive solvation process. On the other hand, the lifetime of the relaxed S_1 state was strongly dependent on the solvent polarity, changing from 40 to 50 ps in acetonitrile to ~20 ps in cyclohexane. Time-resolved fluorescence data also showed subpicosecond transient component that is attributable to the spectral relaxation caused by solvation and/or vibrational relaxation in the S_1 state.

Additional Information

© 2010 Published by Elsevier B.V. Received 12 March 2010; accepted 21 April 2010. Available online 10 May 2010. We thank Professor Tahei Tahara and Dr. Satoshi Takeuchi for their assistance and useful discussions on the time-resolved experiments which have been done at RIKEN. We thank Japan Society for the Promotion of Science (JSPS) for providing a fellowship to Omar F. Mohammed. This work was also supported by chemistry department, Assiut University, Egypt.

Additional details

Created:
August 22, 2023
Modified:
October 20, 2023