Current theoretical challenges in proton-coupled electron transfer: Electron-proton nonadiabaticity, proton relays, and ultrafast dynamics

Proton-coupled electron transfer (PCET) reactions play an important role in a wide range of biological and chemical processes. The motions of the electrons, transferring protons, solute nuclei, and solvent nuclei occur on a wide range of time scales and are often strongly coupled. As a result, the theoretical description of these processes requires a combination of quantum and classical methods. This Perspective discusses three of the current theoretical challenges in the field of PCET. The first challenge is the calculation of electron–proton nonadiabatic effects, which are significant for these reactions because the hydrogen tunneling is often faster than the electronic transition. The second challenge is the modeling of electron transfer coupled to proton transport along hydrogen-bonded networks. The third challenge is the simulation of the ultrafast dynamics of nonequilibrium photoinduced PCET reactions in solution. Insights provided by theoretical studies may assist in the design of more effective ca...

[1]  R. Morris Bullock,et al.  Molecular Electrocatalysts for the Oxidation of Hydrogen and the Production of Hydrogen – The Role of Pendant Amines as Proton Relays , 2011 .

[2]  James M Mayer,et al.  Proton-coupled electron transfer: a reaction chemist's view. , 2004, Annual review of physical chemistry.

[3]  H. Gray,et al.  Proton-coupled electron flow in protein redox machines. , 2010, Chemical reviews.

[4]  D. Nocera,et al.  Proton-coupled electron transfer of tyrosine oxidation: buffer dependence and parallel mechanisms. , 2007, Journal of the American Chemical Society.

[5]  T. Meyer,et al.  Integrating proton coupled electron transfer (PCET) and excited states , 2010 .

[6]  D. Truhlar,et al.  A unified perspective on the hydrogen atom transfer and proton-coupled electron transfer mechanisms in terms of topographic features of the ground and excited potential energy surfaces as exemplified by the reaction between phenol and radicals. , 2008, Journal of the American Chemical Society.

[7]  Michelle C. Y. Chang,et al.  Radical initiation in the class I ribonucleotide reductase: long-range proton-coupled electron transfer? , 2003, Chemical reviews.

[8]  M. Newton,et al.  Calculation of electronic coupling matrix elements for ground and excited state electron transfer reactions: Comparison of the generalized Mulliken-Hush and block diagonalization methods , 1997 .

[9]  G. Voth,et al.  A Centroid Molecular Dynamics Approach for Nonadiabatic Dynamical Processes in Condensed Phases: the Spin-Boson Case† , 2002 .

[10]  Sharon Hammes-Schiffer,et al.  Calculation of vibronic couplings for phenoxyl/phenol and benzyl/toluene self-exchange reactions: implications for proton-coupled electron transfer mechanisms. , 2006, Journal of the American Chemical Society.

[11]  S. P. Webb,et al.  Multiconfigurational nuclear-electronic orbital approach: Incorporation of nuclear quantum effects in electronic structure calculations , 2002 .

[12]  C. Costentin.  Electrochemical approach to the mechanistic study of proton-coupled electron transfer. , 2008, Chemical reviews.

[13]  L. Cederbaum,et al.  Approximately diabatic states from block diagonalization of the electronic Hamiltonian , 1988 .

[14]  S. Hammes-Schiffer,et al.  Development of electron-proton density functionals for multicomponent density functional theory. , 2008, Physical review letters.

[15]  Sharon Hammes-Schiffer,et al.  Theoretical analysis of proton relays in electrochemical proton-coupled electron transfer. , 2011, Journal of the American Chemical Society.

[16]  M. Baer.  Adiabatic and diabatic representations for atom-molecule collisions: Treatment of the collinear arrangement , 1975 .

[17]  Sharon Hammes-Schiffer,et al.  Proton-coupled electron transfer versus hydrogen atom transfer: generation of charge-localized diabatic states. , 2011, The journal of physical chemistry. A.

[18]  Ian R. Craig,et al.  Proton transfer in a polar solvent from ring polymer reaction rate theory. , 2008, The Journal of chemical physics.

[19]  A. Chakraborty,et al.  Inclusion of explicit electron-proton correlation in the nuclear-electronic orbital approach using Gaussian-type geminal functions. , 2008, The Journal of chemical physics.

[20]  R. Cukier.  Proton-Coupled Electron Transfer Reactions: Evaluation of Rate Constants , 1996 .

[21]  C. Crespo-Hernández,et al.  Deuterium isotope effect on excited-state dynamics in an alternating GC oligonucleotide. , 2009, Journal of the American Chemical Society.

[22]  T. Meyer,et al.  Proton-coupled electron transfer. , 2007, Chemical reviews.

[23]  Jinlong Yang,et al.  Ultrafast Interfacial Proton-Coupled Electron Transfer , 2006, Science.

[24]  Javier J. Concepcion,et al.  Concerted electron-proton transfer in the optical excitation of hydrogen-bonded dyes , 2011, Proceedings of the National Academy of Sciences.

[25]  M. Blomberg,et al.  Quantum chemical studies of proton-coupled electron transfer in metalloenzymes. , 2010, Chemical reviews.

[26]  L. Cederbaum,et al.  Adiabatic and quasidiabatic states in a Gauge theoretical framework , 2007 .

[27]  A. Stuchebrukhov,et al.  Concerted electron and proton transfer: Transition from nonadiabatic to adiabatic proton tunneling , 2000 .

[28]  S. Hammes-Schiffer,et al.  Theory of coupled electron and proton transfer reactions. , 2010, Chemical reviews.

[29]  M. Baer.  Electronic non-adiabatic transitions derivation of the general adiabatic-diabatic transformation matrix , 1980 .

[30]  A. Soudackov,et al.  Isotope Effects on the Nonequilibrium Dynamics of Ultrafast Photoinduced Proton-Coupled Electron Transfer Reactions in Solution. , 2011, The journal of physical chemistry letters.

[31]  R I Cukier,et al.  Proton-coupled electron transfer. , 1998, Annual review of physical chemistry.

[32]  A. Chakraborty,et al.  Explicit dynamical electron-proton correlation in the nuclear-electronic orbital framework. , 2006, The journal of physical chemistry. A.

[33]  J. Savéant,et al.  Inserting a hydrogen-bond relay between proton exchanging sites in proton-coupled electron transfers. , 2010, Angewandte Chemie.

[34]  Bertrand Lavédrine,et al.  Cover Picture: The Nature of the Extraordinary Finish of Stradivari’s Instruments (Angew. Chem. Int. Ed. 1/2010) , 2010 .

[35]  H. Gray,et al.  Hydrogen evolution catalyzed by cobaloximes. , 2009, Accounts of chemical research.

[36]  Sharon Hammes-Schiffer,et al.  Proton-coupled electron transfer in solution, proteins, and electrochemistry. , 2008, The journal of physical chemistry. B.

[37]  V. Batista,et al.  Quantum mechanics/molecular mechanics structural models of the oxygen-evolving complex of photosystem II. , 2007, Current opinion in structural biology.

[38]  A. Soudackov,et al.  Role of solvent dynamics in ultrafast photoinduced proton-coupled electron transfer reactions in solution. , 2010, The journal of physical chemistry. B.

[39]  Weston Thatcher Borden,et al.  Proton-coupled electron transfer versus hydrogen atom transfer in benzyl/toluene, methoxyl/methanol, and phenoxyl/phenol self-exchange reactions. , 2002, Journal of the American Chemical Society.