Research Overview

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 novel types of exciplexes, such as vibrationally structured emissions, multiple exciplexes in highly polar media, and most recently on cationic – or charge shift – exciplexes.

Research Interests

• Photo-induced Electron Transfer Reactions

Selected Publications

• Dinnocenzo, J. P.; Merkel, P. B.; Farid, S. “Cationic (Charge Shift) Exciplexes,” J. Phys. Chem. A, 2017, 121, 7903–7909.
• Dinnocenzo, J. P.; Feinberg, A. M.; Farid, S. “Multiple Intermolecular Exciplexes in Highly Polar Solvents,” J. Phys. Chem. A, 2017, 121, 3662–3670.
• Young, R. H.; Feinberg, A. M.; Dinnocenzo, J. P.; Farid, S. “Transition from Charge-Transfer to Largely Locally Excited Exciplexes, from Structureless to Vibrationally Structured Emissions,” Photochem. Photobiol., 2015, 91,624–636.
• Luo, P.; Feinberg, A. M.; Guirado, G.; Farid, S.; Dinnocenzo, J. P. “Accurate Oxidation Potentials of 40 Benzene and Biphenyl Derivatives with Heteroatom Substituents,” J. Org. Chem., 2014, 79, 9297–9304.
• Shukla, D.; Adiga, S. P.; Ahearn, W. G.; Dinnocenzo, J. P.; Farid, S. “Chain-Amplified Photochemical Fragmentation of N-Alkoxypyridinium Salts: Proposed Reaction of Alkoxy Radicals with Pyridine Bases To Give Pyridinyl Radicals,” J. Org. Chem., 2013, 78, 1955–1964.
• Luo, P.; Dinnocenzo, J. P.; Merkel, P. B.; Young, R. H.; Farid, S.  “Bimolecular Electron Transfers That Deviate from the Sandros–Boltzmann Dependence on Free Energy:  Steric Effect,” J. Org. Chem., 2012, 77, 1632-1639.
• 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.2011, 133, 11580-11587.
• 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.2011, 133, 4791-4801.
• 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.2009, 74, 5163-5173.
• 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.2008, 73, 5683-5692.
• 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.2007, 72, 6970-6981.
• Gould, I.R., Farid S. "Radiationless Decay in Exciplexes With Variable Charge-Transfer," J. Phys. Chem. B2007, 11, 6782-6787.
• 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," Macromolecules2005, 38, 7684-7694.
• Shukla, D., Ahearn, W.G., Farid, S. "Chain Amplification in Photoreactions of N-Alkoxypyridinium Salts with Alcohols: Mechanism and Kinetics," J. Org. Chem.2005, 70, 6809-6819.
• 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.2005, 70, 3791-3800.
• Gould, I.R, Lenhard, J.R., Farid, S. "A Curve-Crossing Model for Oxidative Decarboxylation. Kinetics of Anilino Carboxylate Fragmentation," J. Phys. Chem. A2004, 108, 10949-10956.
• Shukla, D, Young, R.H., Farid, S. "Reducing Power of Photogenerated α-Hydroxy Radicals. Proton-Coupled Electron Transfer," J. Phys. Chem. A2004, 108, 10386-10394.
• 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.2003, 2, 1169-1176.
• Gould, I.R., Boiani, J.A., Gailard, E.B., Goodman, J.L., Farid, S. "Intersystem Crossing in Charge-Transfer Excited States," J. Phys. Chem. A2003, 107, 3515-3524.
• 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. Acta2001, 84, 2796-2812.
• 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.2000, 122, 11934-11943.
• 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.1997, 119, 1876-1883.