Samir Farid

Samir Farid

Research Professor


Ph.D. 1967, Universität Göttingen

Photo-induced Electron Transfer Reactions

The scope of organic photochemistry has been significantly broadened through reactions that proceed via electron transfer. The dynamics of radical ion pairs (contact and solvent-separated) and the factors that control their radiative and nonradiative decay provided a framework to design efficient photoinduced electron transfer reactions. Investigating these reactions relied on the combined use of several transient and steady state kinetics. Current interest is on electron transfer reactions that take place only when coupled with a chemical transformation (e.g., bond cleavage, bond formation or proton transfer). Careful examination of several reactions revealed that these bond-coupled electron transfer reactions (uni-, bi-, and ter-molecular) are not uncommon. A second theme of the current research is on quantum amplification. Very high quantum yields were achieved in complex chain reactions involving free radicals that proceed via electron transfer, as well as those propagated via adiabatic reactions in the triplet state.

Selected Publications

Farid, S., Dinnocenzo, J. P., Merkel, P. B., Young, R. H., Shukla, D., Guirado, G.  "Reexamination of the Rehm-Weller Data Set Reveals Electron Transfer Quenching that Follows a Sandros-Boltzmann Dependence on Free Energy,"  J. Am. Chem. Soc.  201113311580-11587.
Farid, S., Dinnocenzo, J. P., Merkel, P. B., Young, R. H., Shukla, D.  "Bimolecular Electron Transfers that Follow a Sandros-Boltzmann Dependence on Free Energy,"  J. Am. Chem. Soc.  20111334791-4801.
Merkel, P.B., Luo, P., Dinnocenzo, J.P., and Farid, S.  "Accurate Oxidation Potentials of Benzene and Biphenyl Derivatives via Electron-Transfer Equilibria and Transient Kinetics,"  J. Org. Chem.  2009745163-5173.
Ferrar, L., Mis, M., Dinnocenzo, J.P., Farid, S., Merkel, P.B., Robello, D.R.   "Quantum Amplified Isomerization in Polymers Based on Triplet Chain Reactions,"  J. Org. Chem.  2008735683-5692.
Wang, Y., Haze, O., Dinnocenzo, J.P., Farid S., Farid, R.S., Gould, I.R.   "Bonded Exciplex. A New Concept in Photochemcial Reactions,"  J. Org. Chem.  2007726970-6981.
Gould, I.R., Farid S.  "Radiationless Decay in Exciplexes With Variable Charge-Transfer,"  J. Phys. Chem. B  2007116782-6787.
Gillmore, J.G., Neiser, J.D., McManus, K.A., Roh, Y., Dombrowski, G.W., Brown, T.G., Dinnocenzo, J.P., Farid, S., Robello, D.R.  "Quantum Amplified Isomerization: A New Concept for Polymeric Optical Materials,"  Macromolecules  2005387684-7694.
Shukla, D., Ahearn, W.G., Farid, S.  "Chain Amplification in Photoreactions of N-Alkoxypyridinium Salts with Alcohols: Mechanism and Kinetics,"  J. Org. Chem.  2005706809-6819.
Dombrowski, G.W., Dinnocenzo, J.P., Zielinski, P.A., Farid, S., Wosinska, Z., Gould, I.R.  "Efficient Unimolecular Deprotonation of Amine Radical Cations,"  J. Org. Chem.  2005703791-3800.
Gould, I.R, Lenhard, J.R., Farid, S.  "A Curve-Crossing Model for Oxidative Decarboxylation. Kinetics of Anilino Carboxylate Fragmentation,"  J. Phys. Chem. A  200410810949-10956.
Shukla, D, Young, R.H., Farid, S.  "Reducing Power of Photogenerated α-Hydroxy Radicals. Proton-Coupled Electron Transfer,"  J. Phys. Chem. A  200410810386-10394.
Wang, Y., Luttrull, D.K., Dinnocenzo, J.P., Goodman, J.L., Farid, S., Gould, I.R.  "Associative Return Electron Transfer. A Bond-Coupled Electron Transfer in the Photoreactions of Cyclopropylamines,"  Photochem. Photobiol. Sci.  200321169-1176.
Gould, I.R., Boiani, J.A., Gailard, E.B., Goodman, J.L., Farid, S.  "Intersystem Crossing in Charge-Transfer Excited States,"  J. Phys. Chem. A  20031073515-3524.
Gould, I.R., Shukla, D., Giesen D., Farid, S.  "Energetics of Electron-Transfer Reactions of Photoinitiated Polymerization: Dye-Sensitized Fragmentation of N-Alkoxypyridinium Salts,"  Helv. Chim. Acta  2001842796-2812.
Gould, I.R., Lenhard, J.R., Muenter, A.A., Godleski, S.A., Farid, S.  "Two-Electron Sensitization: A New Concept for Silver Halide Photography,"  J. Am. Chem. Soc.  200012211934-11943.
Dockery, K.P., Dinnocenzo, J.P., Farid, S., Goodman, J.L., Gould, I.R., Todd, W.P.  "Nucleophile-Assisted Cleavage of Benzyltrialkylsilane Cation Radicals,"  J. Am. Chem. Soc.  19971191876-1883.
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Professor Farid's Contact Information...

Office: Hutchison 220E
Phone: (585) 275-8398