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text Dlott, Dana D. Miers, Jeffrey Britt 2011-05-07T13:11:54Z 2011-05-07T13:11:54Z 10000-01-01 1992 Picosecond flash photolysis is used to study the recombination of carbon monoxide to protoheme in glycerol:water over ten decades in time (1 ps to 10 ms). The rebinding consists of an initial nonexponential geminate phase followed by a slower exponential bimolecular phase. The entire time course of this reaction between 260 and 300 K can be explained in a unified way using a simple, analytically tractable diffusion model involving just three parameters: the relative diffusion constant, the contact radius, and the intrinsic rate of reaction at contact. Fiber-optic pulse compression of the picosecond laser is used to increase the temporal resolution of the apparatus from 2 ps to 250 fs. The femtosecond pulses are subsequently used to observe back electron transfer in pyrylium borate ( (Py$\sp+$) (Ar$\sb4$B$\sp-$)) ion pairs in benzene. Substituent groups on the borate are varied in a systematic way to change the driving force, $\Delta{\rm G}\sb{\rm bet}$, of the back transfer reaction. Back transfer rates between 6.3 $\times$ 10$\sp{10}$ and 2.6 $\times$ 10$\sp{11}$ s$\sp{-1}$ are observed. Plots of k$\sb{\rm bet}$ vs. $\Delta{\rm G}\sb{\rm bet}$ show a Marcus inverted region. The forward and back rates are not equal because different molecular orbitals are involved depending on the direction of transfer. The research in this thesis was supported by the National Science Foundation through grants NSF DMR 87-21243 and NSF DMR 91-04130. Some of the equipment used in this work was partially supported by the US Army Research Office through grant DAALO3-90-G-0030. The author acknowledges support from a Molecular Biophysics Traineeship on Public Health Service Grant GM08276 and, during the preparation of this thesis, by the MFEL program through the Office of Naval Research contract N00014-91-C-0170. Made available in DSpace on 2011-05-07T13:11:54Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9236542.pdf: 4587669 bytes, checksum: 34c209193f76194fd0855fe5363d713f (MD5) Previous issue date: 1992 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:51:32Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:23:40-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI9236542 (UMI)AAI9236542 http://hdl.handle.net/2142/21549 eng Copyright 1992 Miers, Jeffrey Britt Chemistry, Physical Biophysics, General Ultrafast studies of diffusion and electron transfer Chemistry Chemistry University of Illinois at Urbana-Champaign Dissertation Ph.D.