Charles B. Harris

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Biotechnology Directorate. We thank P. Skelton and J. B. Lester for assistance with, respectively, mass spectrometry and DNA sequencing; A. L. Cutter for authentic samples of triketide lactones; H. A. I. McArthur and J. Dirlam for helpful discussions; and D. Hopwood and C. Khosla for the kind provision of S. coelicolor CH999 and plasmid pRM5. We also wish(More)
Many properties of chemical reactions are determined by the transition state connecting reactant and product, yet it is difficult to directly obtain any information about these short-lived structures in liquids. We show that two-dimensional infrared (2D-IR) spectroscopy can provide direct information about transition states by tracking the transformation of(More)
Two-photon photoemission is a promising new technique that has been developed for the study of electron dynamics at interfaces. A femtosecond laser is used to both create an excited electronic distribution at the surface and eject the distribution for subsequent energy analysis. Time- and momentum-resolved two-photon photoemission spectra as a function of(More)
The dynamics of excited electrons in insulator quantum well states on a metal substrate were determined by femtosecond two-photon photoemission for the first time. Lifetimes are reported for the first three excited states for 1– 6 atomic layers of Xe on Ag(111). As the image states evolve into quantum well states with increasing coverage, the lifetimes(More)
Caught in the light: The fulvalene diruthenium complex shown on the left side of the picture captures sun light, causing initial Ru-Ru bond rupture to furnish a long-lived triplet biradical of syn configuration. This species requires thermal activation to reach a crossing point (middle) into the singlet manifold on route to its thermal storage isomer on the(More)
A delocalized electron at a metal-dielectric interface interacts with the adlayer and spatially localizes or self-traps on the femtosecond time scale into what is termed a small polaron. The dynamics can be studied by two-photon photoemission. Theoretical and experimental analyses reveal the interaction energy and the lattice vibrational mode that mediates(More)
Ultrafast two-photon photoemission has been used to study electron solvation at two-dimensional metal/polar-adsorbate interfaces. The molecular motion that causes the excess electron solvation is manifested as a dynamic shift in the electronic energy. Although the initially excited electron is delocalized in the plane of the interface, interactions with the(More)