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 January 7, 2005 | public
Journal Article

Electron Tunneling Through Organic Molecules in Frozen Glasses

Abstract

Reaction rates extracted from measurements of donor luminescence quenching by randomly dispersed electron acceptors reveal an exponential decay constant of 1.23 per angstrom for electron tunneling through a frozen toluene glass (with a barrier to tunneling of 1.4 electron volts). The decay constant is 1.62 per angstrom (the barrier, 2.6 electron volts) in a frozen 2-methyl-tetrahydrofuran glass. Comparison to decay constants for tunneling across covalently linked xylyl (0.76 per angstrom) and alkyl (1.0 per angstrom) bridges leads to the conclusion that tunneling between solvent molecules separated by ∼2 angstroms (van der Waals contact) is 20 to 50 times slower than tunneling through a comparable length of a covalently bonded bridge. Our results provide experimental confirmation that covalently bonded pathways can facilitate electron flow through folded polypeptide structures.

Additional Information

© 2005 American Association for the Advancement of Science. 9 August 2004; Accepted 23 November 2004. We thank J. Kim, J. Lee, and J. Magyar for several helpful discussions. Supported by BP, the NSF (grant no. CHE-0078809), and the Arnold and Mabel Beckman Foundation. O.S.W. acknowledges a postdoctoral fellowship from the Swiss National Science Foundation and B.S.L., a graduate fellowship from the Parsons Foundation.

Additional details

Created:
August 19, 2023
Modified:
October 18, 2023