1
|
Liu K, Zhang J, Shi Q, Ding L, Liu T, Fang Y. Precise Manipulation of Excited-State Intramolecular Proton Transfer via Incorporating Charge Transfer toward High-Performance Film-Based Fluorescence Sensing. J Am Chem Soc 2023; 145:7408-7415. [PMID: 36930832 DOI: 10.1021/jacs.2c13843] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Abstract
Excited-state intramolecular proton transfer (ESIPT) has been widely employed for the design of a variety of functionality-led molecular systems. However, precise manipulation of the excited-state reaction is challenging. Herein, we report a new tactic for tuning ESIPT via incorporating an excited-state intramolecular charge transfer (ESICT) process. Specifically, three o-carborane derivatives, NaCBO, PaCBO, and PyCBO, were designed, where the 2-(2'-hydroxyphenyl)-benzothiazole is a typical ESIPT unit functioning as an electron acceptor, and the electron-donating units are naphthyl-(Na), phenanthrenyl-(Pa), and pyrenyl-(Py), respectively. The architectures of the molecules are featured with a face-to-face alignment of the two units. Spectroscopy and theoretical calculation studies revealed that the electron-donating capacity of the donors and solvent polarity continuously modulate the ESIPT/ESICT energetics and dynamics, resulting in distinct emissions. Moreover, the molecules depicted not only highly porous structures but also very different fluorescent colors in the solid state, enabling highly selective film-based fluorescence sensing of mustard gas simulant, 2-chloroethyl ethyl sulfide, with a detection limit of 50 ppb and a response time of 5 s. This work thus provides a reliable strategy for the creation of high-performance sensing fluorophores via ESIPT manipulation.
Collapse
Affiliation(s)
- Ke Liu
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Shaanxi, Xi'an 710062, China
| | - Jing Zhang
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Shaanxi, Xi'an 710062, China
| | - Qiyuan Shi
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Shaanxi, Xi'an 710062, China
| | - Liping Ding
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Shaanxi, Xi'an 710062, China
| | - Taihong Liu
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Shaanxi, Xi'an 710062, China
| | - Yu Fang
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Shaanxi, Xi'an 710062, China
| |
Collapse
|
2
|
Demchenko AP. Proton transfer reactions: from photochemistry to biochemistry and bioenergetics. BBA ADVANCES 2023. [DOI: 10.1016/j.bbadva.2023.100085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023] Open
|
3
|
Rimgard BP, Tao Z, Parada GA, Cotter LF, Hammes-Schiffer S, Mayer JM, Hammarström L. Proton-coupled energy transfer in molecular triads. Science 2022; 377:742-747. [PMID: 35862490 PMCID: PMC9597948 DOI: 10.1126/science.abq5173] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We experimentally discovered and theoretically analyzed a photochemical mechanism, which we term proton-coupled energy transfer (PCEnT). A series of anthracene-phenol-pyridine triads formed a local excited anthracene state after light excitation at a wavelength of ~400 nanometers (nm), which led to fluorescence around 550 nm from the phenol-pyridine unit. Direct excitation of phenol-pyridine would have required ~330-nm light, but the coupled proton transfer within the phenol-pyridine unit lowered its excited-state energy so that it could accept excitation energy from anthracene. Singlet-singlet energy transfer thus occurred despite the lack of spectral overlap between the anthracene fluorescence and the phenol-pyridine absorption. Moreover, theoretical calculations indicated negligible charge transfer between the anthracene and phenol-pyridine units. We construe PCEnT as an elementary reaction of possible relevance to biological systems and future photonic devices.
Collapse
Affiliation(s)
| | - Zhen Tao
- Yale University, Department of Chemistry, New Haven, Connecticut 06520, USA
| | - Giovanny A. Parada
- Yale University, Department of Chemistry, New Haven, Connecticut 06520, USA
- The College of New Jersey, Department of Chemistry, Ewing, NJ 08628, USA
| | - Laura F. Cotter
- Yale University, Department of Chemistry, New Haven, Connecticut 06520, USA
| | | | - James M. Mayer
- Yale University, Department of Chemistry, New Haven, Connecticut 06520, USA
| | - Leif Hammarström
- Uppsala University, Department of Chemistry, Ångström laboratory, Uppsala, Box 523, SE75120, Sweden
| |
Collapse
|
4
|
Geeraerts Z, Stiller OR, Lukat-Rodgers GS, Rodgers KR. Roles of High-Valent Hemes and pH Dependence in Halite Decomposition Catalyzed by Chlorite Dismutase from Dechloromonas aromatica. ACS Catal 2022; 12:8641-8657. [DOI: 10.1021/acscatal.2c01428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zachary Geeraerts
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Olivia R. Stiller
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Gudrun S. Lukat-Rodgers
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Kenton R. Rodgers
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| |
Collapse
|
5
|
Chen L, Fournier JA. Probing Hydrogen-Bonding Interactions within Phenol-Benzimidazole Proton-Coupled Electron Transfer Model Complexes with Cryogenic Ion Vibrational Spectroscopy. J Phys Chem A 2021; 125:9288-9297. [PMID: 34652915 DOI: 10.1021/acs.jpca.1c05879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hydrogen-bonding interactions within a series of phenol-benzimidazole model proton-coupled electron transfer (PCET) dyad complexes are characterized using cryogenic ion vibrational spectroscopy. A highly red-shifted and surprisingly broad (>1000 cm-1) transition is observed in one of the models and assigned to the phenolic OH stretch strongly H-bonded to the N(3) benzimidazole atom. The breadth is attributed to a combination of anharmonic Fermi-resonance coupling between the OH stretch and background doorway states involving OH bending modes and strong coupling of the OH stretch frequency to structural deformations along the proton-transfer coordinate accessible at the vibrational zero-point level. The other models show unexpected protonation of the benzimidazole group upon electrospray ionization instead of at more basic remote amine/amide groups. This leads to the formation of HO-+HN(3) H-bond motifs that are much weaker than the OH-N(3) H-bond arrangement. H-bonding between the N(1)H+ benzimidazole group and the carbonyl on the tyrosine backbone is the stronger and preferred interaction in these complexes. The results show that conjugation effects, secondary H-bond interactions, and H-bond soft modes strongly influence the OH-N(3) interaction and highlight the importance of the direct monitoring of proton stretch transitions in characterizing the proton-transfer reaction coordinate in PCET systems.
Collapse
Affiliation(s)
- Liangyi Chen
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Joseph A Fournier
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| |
Collapse
|
6
|
Cotter L, Rimgard BP, Parada GA, Mayer JM, Hammarström L. Solvent and Temperature Effects on Photoinduced Proton-Coupled Electron Transfer in the Marcus Inverted Region. J Phys Chem A 2021; 125:7670-7684. [PMID: 34432465 PMCID: PMC8436208 DOI: 10.1021/acs.jpca.1c05764] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/09/2021] [Indexed: 11/29/2022]
Abstract
Concerted proton-coupled electron transfer (PCET) in the Marcus inverted region was recently demonstrated (Science 2019, 364, 471-475). Understanding the requirements for such reactivity is fundamentally important and holds promise as a design principle for solar energy conversion systems. Herein, we investigate the solvent polarity and temperature dependence of photoinduced proton-coupled charge separation (CS) and charge recombination (CR) in anthracene-phenol-pyridine triads: 1 (10-(4-hydroxy-3-(4-methylpyridin-2-yl)benzyl)anthracene-9-carbonitrile) and 2 (10-(4-hydroxy-3-(4-methoxypyridin-2-yl)benzyl)anthracene-9-carbonitrile). Both the CS and CR rate constants increased with increasing polarity in acetonitrile:n-butyronitrile mixtures. The kinetics were semi-quantitatively analyzed where changes in dielectric and refractive index, and thus consequently changes in driving force (-ΔG°) and reorganization energy (λ), were accounted for. The results were further validated by fitting the temperature dependence, from 180 to 298 K, in n-butyronitrile. The analyses support previous computational work where transitions to proton vibrational excited states dominate the CR reaction with a distinct activation free energy (ΔG*CR ∼ 140 meV). However, the solvent continuum model fails to accurately describe the changes in ΔG° and λ with temperature via changes in dielectric constant and refractive index. Satisfactory modeling was obtained using the results of a molecular solvent model [J. Phys. Chem. B 1999, 103, 9130-9140], which predicts that λ decreases with temperature, opposite to that of the continuum model. To further assess the solvent polarity control in the inverted region, the reactions were studied in toluene. Nonpolar solvents decrease both ΔG°CR and λ, slowing CR into the nanosecond time regime for 2 in toluene at 298 K. This demonstrates how PCET in the inverted region may be controlled to potentially use proton-coupled CS states for efficient solar fuel production and photoredox catalysis.
Collapse
Affiliation(s)
- Laura
F. Cotter
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | | | - Giovanny A. Parada
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - James M. Mayer
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Leif Hammarström
- Department
of Chemistry − Ångström Laboratory, Uppsala University, Box 523, SE75120 Uppsala, Sweden
| |
Collapse
|
7
|
Natali M, Amati A, Demitri N, Iengo E. Photoinduced Electron vs. Concerted Proton Electron Transfer Pathways in Sn IV (l-Tryptophanato) 2 Porphyrin Conjugates. Chemistry 2021; 27:7872-7881. [PMID: 33780047 PMCID: PMC8252543 DOI: 10.1002/chem.202005487] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Indexed: 01/01/2023]
Abstract
Aromatic amino acids such as l‐tyrosine and l‐tryptophan are deployed in natural systems to mediate electron transfer (ET) reactions. While tyrosine oxidation is always coupled to deprotonation (proton‐coupled electron‐transfer, PCET), both ET‐only and PCET pathways can occur in the case of the tryptophan residue. In the present work, two novel conjugates 1 and 2, based on a SnIV tetraphenylporphyrin and SnIV octaethylporphyrin, respectively, as the chromophore/electron acceptor and l‐tryptophan as electron/proton donor, have been prepared and thoroughly characterized by a combination of different techniques including single crystal X‐ray analysis. The photophysical investigation of 1 and 2 in CH2Cl2 in the presence of pyrrolidine as a base shows that different quenching mechanisms are operating upon visible‐light excitation of the porphyrin component, namely photoinduced electron transfer and concerted proton electron transfer (CPET), depending on the chromophore identity and spin multiplicity of the excited state. The results are compared with those previously described for metal‐mediated analogues featuring SnIV porphyrin chromophores and l‐tyrosine as the redox active amino acid and well illustrate the peculiar role of l‐tryptophan with respect to PCET.
Collapse
Affiliation(s)
- Mirco Natali
- Department of Chemical, Pharmaceutical and Agricultural Sciences (DOCPAS), University of Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy.,Centro Interuniversitario per la Conversione Chimica dell'Energia Solare (SolarChem), sez. di Ferrara, Via L. Borsari 46, 44121, Ferrara, Italy
| | - Agnese Amati
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127, Trieste, Italy.,Current address: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Nicola Demitri
- Electra-Sincrotrone Trieste, S.S. 14 Km 163.5 in Area Science Park, 34149 Basovizza, Trieste, Italy
| | - Elisabetta Iengo
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127, Trieste, Italy
| |
Collapse
|
8
|
Yang JY, Kerr TA, Wang XS, Barlow JM. Reducing CO2 to HCO2– at Mild Potentials: Lessons from Formate Dehydrogenase. J Am Chem Soc 2020; 142:19438-19445. [DOI: 10.1021/jacs.0c07965] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Jenny Y. Yang
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Tyler A. Kerr
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Xinran S. Wang
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Jeffrey M. Barlow
- Department of Chemistry, University of California, Irvine, California 92697, United States
| |
Collapse
|
9
|
Liu ZY, Hu JW, Huang TH, Chen KY, Chou PT. Excited-state intramolecular proton transfer in the kinetic-control regime. Phys Chem Chem Phys 2020; 22:22271-22278. [PMID: 33001109 DOI: 10.1039/d0cp03408h] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A new series of molecules bearing a 2,11-dihydro-1H-cyclopenta[de]indeno[1,2-b]quinoline (CPIQ) chromophore with the N-HN type of intramolecular hydrogen bond are strategically designed and synthesized, among which CPIQ-OH, CPIQ-NHAc and CPIQ-NHTs in solution exhibit a single emission band with an anomalously large Stokes shift, whereas CPIQ-NH2 and CPIQ-NHMe show apparent dual-emission property. This, in combination with time-resolved spectroscopy and the computational approach, leads us to conclude that CPIQ-OH, CPIQ-NHAc and CPIQ-NHTs undergo ultrafast, highly exergonic excited-state intramolecular proton transfer (ESIPT), while a finite rate of ESIPT is observed for CPIQ-NH2 and CPIQ-NHMe with a time constant of 117 ps and 39 ps, respectively, in acetonitrile at room-temperature. Further temperature-dependent studies deduce an appreciable ESIPT barrier for CPIQ-NH2 and CPIQ-NHMe. Different from most of the barrier associated ESIPT molecules that are commonly in the thermodynamic-control regime, i.e. found in the thermal pre-equilibrium between excited normal and proton-transfer tautomer states, CPIQ-NH2 and CPIQ-NHMe cases are in the kinetic-control regime where ESIPT is irreversible with a significant barrier. The barrier is able to be tuned by the electronic properties of the -R group in the NR-H proton donor site, resulting in ratiometric fluorescence for normal versus tautomer emission.
Collapse
Affiliation(s)
- Zong-Ying Liu
- Department of Chemistry, National Taiwan University, Taipei, 10617 Taiwan, Republic of China.
| | | | | | | | | |
Collapse
|
10
|
Sayfutyarova ER, Hammes-Schiffer S. Excited State Molecular Dynamics of Photoinduced Proton-Coupled Electron Transfer in Anthracene-Phenol-Pyridine Triads. J Phys Chem Lett 2020; 11:7109-7115. [PMID: 32787327 DOI: 10.1021/acs.jpclett.0c02012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Photoinduced proton-coupled electron transfer (PCET) in anthracene-phenol-pyridine triads exhibits inverted region behavior, where the more thermodynamically favorable process is slower. The long-lived transient charge-separated state (CSS) associated with electron transfer from phenol to anthracene and inverted region behavior were only observed experimentally for certain triads. Herein, excited state molecular dynamics simulations were performed on four different triads to simulate the nonequilibrium dynamics following photoexcitation to the locally excited state (LES) of anthracene. These simulations identified two distinct PCET pathways: the triads exhibiting inverted region behavior transitioned from the LES to the CSS, whereas the other triads transitioned to a local electron-proton transfer (LEPT) state within phenol and pyridine. The simulations suggest that PCET to the LEPT state is slower than PCET to the CSS and provides an alternative relaxation pathway. The mechanistic pathways, as well as the time scales of the electron and proton transfers, can be controlled by tuning the substituents.
Collapse
Affiliation(s)
- Elvira R Sayfutyarova
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| |
Collapse
|
11
|
Koronkiewicz B, Swierk J, Regan K, Mayer JM. Shallow Distance Dependence for Proton-Coupled Tyrosine Oxidation in Oligoproline Peptides. J Am Chem Soc 2020; 142:12106-12118. [PMID: 32510937 PMCID: PMC7545454 DOI: 10.1021/jacs.0c01429] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We have explored the kinetic effect of increasing electron transfer (ET) distance in a biomimetic, proton-coupled electron-transfer (PCET) system. Biological ET often occurs simultaneously with proton transfer (PT) in order to avoid the high-energy, charged intermediates resulting from the stepwise transfer of protons and electrons. These concerted proton-electron-transfer (CPET) reactions are implicated in numerous biological ET pathways. In many cases, PT is coupled to long-range ET. While many studies have shown that the rate of ET is sensitive to the distance between the electron donor and acceptor, extensions to biological CPET reactions are sparse. The possibility of a unique ET distance dependence for CPET reactions deserves further exploration, as this could have implications for how we understand biological ET. We therefore explored the ET distance dependence for the CPET oxidation of tyrosine in a model system. We prepared a series of metallopeptides with a tyrosine separated from a Ru(bpy)32+ complex by an oligoproline bridge of increasing length. Rate constants for intramolecular tyrosine oxidation were measured using the flash-quench transient absorption technique in aqueous solutions. The rate constants for tyrosine oxidation decreased by 125-fold with three added proline residues between tyrosine and the oxidant. By comparison, related intramolecular ET rate constants in very similar constructs were reported to decrease by 4-5 orders of magnitude over the same number of prolines. The observed shallow distance dependence for tyrosine oxidation is proposed to originate in part from the requirement for stronger oxidants, leading to a smaller hole-transfer effective tunneling barrier height. The shallow distance dependence observed here and extensions to distance-dependent CPET reactions have potential implications for long-range charge transfers.
Collapse
Affiliation(s)
- Brian Koronkiewicz
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - John Swierk
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Kevin Regan
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - James M Mayer
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| |
Collapse
|
12
|
Swords WB, Meyer GJ, Hammarström L. Excited-state proton-coupled electron transfer within ion pairs. Chem Sci 2020; 11:3460-3473. [PMID: 34109019 PMCID: PMC8152629 DOI: 10.1039/c9sc04941j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The use of light to drive proton-coupled electron transfer (PCET) reactions has received growing interest, with recent focus on the direct use of excited states in PCET reactions (ES-PCET). Electrostatic ion pairs provide a scaffold to reduce reaction orders and have facilitated many discoveries in electron-transfer chemistry. Their use, however, has not translated to PCET. Herein, we show that ion pairs, formed solely through electrostatic interactions, provide a general, facile means to study an ES-PCET mechanism. These ion pairs formed readily between salicylate anions and tetracationic ruthenium complexes in acetonitrile solution. Upon light excitation, quenching of the ruthenium excited state occurred through ES-PCET oxidation of salicylate within the ion pair. Transient absorption spectroscopy identified the reduced ruthenium complex and oxidized salicylate radical as the primary photoproducts of this reaction. The reduced reaction order due to ion pairing allowed the first-order PCET rate constants to be directly measured through nanosecond photoluminescence spectroscopy. These PCET rate constants saturated at larger driving forces consistent with approaching the Marcus barrierless region. Surprisingly, a proton-transfer tautomer of salicylate, with the proton localized on the carboxylate functional group, was present in acetonitrile. A pre-equilibrium model based on this tautomerization provided non-adiabatic electron-transfer rate constants that were well described by Marcus theory. Electrostatic ion pairs were critical to our ability to investigate this PCET mechanism without the need to covalently link the donor and acceptor or introduce specific hydrogen bonding sites that could compete in alternate PCET pathways.
Collapse
Affiliation(s)
- Wesley B Swords
- Department of Chemistry, Ångström Laboratories, Uppsala University Box 523 SE75120 Uppsala Sweden .,Department of Chemistry, University of North Carolina at Chapel Hill Chapel Hill 27599 USA
| | - Gerald J Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill Chapel Hill 27599 USA
| | - Leif Hammarström
- Department of Chemistry, Ångström Laboratories, Uppsala University Box 523 SE75120 Uppsala Sweden
| |
Collapse
|
13
|
Sayfutyarova ER, Hammes-Schiffer S. Substituent Effects on Photochemistry of Anthracene-Phenol-Pyridine Triads Revealed by Multireference Calculations. J Am Chem Soc 2019; 142:487-494. [PMID: 31846322 DOI: 10.1021/jacs.9b11425] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Inverted region behavior for concerted proton-coupled electron transfer (PCET) was recently demonstrated for biomimetic anthracene-phenol-pyridine molecular triads. Photoexcitation of the anthracene to a locally excited state (LES) is followed by concerted electron transfer from the phenol to the anthracene and proton transfer from the phenol to the pyridine, forming a relatively long-lived charge separated state (CSS). The long-lived CSS and the inverted region behavior associated with the decay from the CSS to the ground state through charge recombination were experimentally observed only for triads with certain substituents on the anthracene and the pyridine. To explain this distinction, we computed the proton potential energy curves in four substituted triads using the complete active space self-consistent-field method and multireference perturbation theory, including solvent effects with a dielectric continuum model. The calculations revealed a local electron-proton transfer (LEPT) state, in which both the electron and proton transfer from the phenol to the pyridine. When the LEPT state is lower in energy than the CSS, it may provide an alternative pathway for fast decay from the LES to the ground state and thereby preclude detection of the CSS and the inverted region behavior. These calculations predict that substituents stabilizing negative charge on the pyridine and destabilizing negative charge on the anthracene will favor the LEPT pathway, while substituents with the reverse effects will favor the CSS pathway, which could exhibit inverted region behavior. These insights about the stabilization of energy-storing charge-separated states have implications for designing and controlling PCET reactions in artificial photosynthetic systems and other energy conversion processes.
Collapse
Affiliation(s)
- Elvira R Sayfutyarova
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520 , United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520 , United States
| |
Collapse
|
14
|
Goldsmith ZK, Soudackov AV, Hammes-Schiffer S. Theoretical analysis of the inverted region in photoinduced proton-coupled electron transfer. Faraday Discuss 2019; 216:363-378. [PMID: 31017599 PMCID: PMC6620152 DOI: 10.1039/c8fd00240a] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Photoinduced proton-coupled electron transfer (PCET) plays a key role in a wide range of energy conversion processes, and understanding how to design systems to control the PCET rate constant is a significant challenge. Herein a theoretical formulation of PCET is utilized to identify the conditions under which photoinduced PCET may exhibit inverted region behavior. In the inverted region, the rate constant decreases as the driving force increases even though the reaction becomes more thermodynamically favorable. Photoinduced PCET will exhibit inverted region behavior when the following criteria are satisfied: (1) the overlap integrals corresponding to the ground reactant and the excited product proton vibrational wavefunctions become negligible for a low enough product vibronic state and (2) the reaction free energies associated with the lower excited product proton vibrational wavefunctions contributing significantly to the rate constant are negative with magnitudes greater than the reorganization energy. These criteria are typically not satisfied by harmonic or Morse potentials but are satisfied by more realistic asymmetric double well potentials because the proton vibrational states above the barrier correspond to more delocalized proton vibrational wavefunctions with nodal structures leading to destructive interference effects. Thus, this theoretical analysis predicts that inverted region behavior could be observed for systems with asymmetric double well potentials characteristic of hydrogen-bonded systems and that the hydrogen/deuterium kinetic isotope effect will approach unity and could even become inverse in this region due to the oscillatory nature of the highly excited vibrational wavefunctions. These insights may help guide the design of more effective energy conversion devices.
Collapse
Affiliation(s)
- Zachary K Goldsmith
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA.
| | - Alexander V Soudackov
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA.
| | - Sharon Hammes-Schiffer
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA.
| |
Collapse
|
15
|
Parada GA, Goldsmith ZK, Kolmar S, Pettersson Rimgard B, Mercado BQ, Hammarström L, Hammes-Schiffer S, Mayer JM. Concerted proton-electron transfer reactions in the Marcus inverted region. Science 2019; 364:471-475. [PMID: 30975771 PMCID: PMC6681808 DOI: 10.1126/science.aaw4675] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/28/2019] [Indexed: 11/02/2022]
Abstract
Electron transfer reactions slow down when they become very thermodynamically favorable, a counterintuitive interplay of kinetics and thermodynamics termed the inverted region in Marcus theory. Here we report inverted region behavior for proton-coupled electron transfer (PCET). Photochemical studies of anthracene-phenol-pyridine triads give rate constants for PCET charge recombination that are slower for the more thermodynamically favorable reactions. Photoexcitation forms an anthracene excited state that undergoes PCET to create a charge-separated state. The rate constants for return charge recombination show an inverted dependence on the driving force upon changing pyridine substituents and the solvent. Calculations using vibronically nonadiabatic PCET theory yield rate constants for simultaneous tunneling of the electron and proton that account for the results.
Collapse
Affiliation(s)
| | | | - Scott Kolmar
- Department of Chemistry, Yale University, New Haven, CT, USA
| | | | | | - Leif Hammarström
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala, Sweden.
| | | | - James M Mayer
- Department of Chemistry, Yale University, New Haven, CT, USA.
| |
Collapse
|
16
|
Bae SH, Li XX, Seo MS, Lee YM, Fukuzumi S, Nam W. Tunneling Controls the Reaction Pathway in the Deformylation of Aldehydes by a Nonheme Iron(III)–Hydroperoxo Complex: Hydrogen Atom Abstraction versus Nucleophilic Addition. J Am Chem Soc 2019; 141:7675-7679. [DOI: 10.1021/jacs.9b02272] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Seong Hee Bae
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Xiao-Xi Li
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Mi Sook Seo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- Faculty of Science and Engineering, Meijo University, SENTAN, Japan Science and Technology Agency (JST), Nagoya, Aichi 468-8502, Japan
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences, Lanzhou 730000, China
| |
Collapse
|
17
|
Pannwitz A, Wenger OS. Proton-coupled multi-electron transfer and its relevance for artificial photosynthesis and photoredox catalysis. Chem Commun (Camb) 2019; 55:4004-4014. [DOI: 10.1039/c9cc00821g] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Photoinduced PCET meets catalysis, and the accumulation of multiple redox equivalents is of key importance.
Collapse
Affiliation(s)
- Andrea Pannwitz
- Department of Chemistry
- University of Basel
- 4056 Basel
- Switzerland
| | | |
Collapse
|
18
|
Pannwitz A, Wenger OS. Recent advances in bioinspired proton-coupled electron transfer. Dalton Trans 2019; 48:5861-5868. [DOI: 10.1039/c8dt04373f] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Fundamental aspects of PCET continue to attract attention. Understanding this reaction type is desirable for small-molecule activation and solar energy conversion.
Collapse
Affiliation(s)
- Andrea Pannwitz
- Department of Chemistry
- University of Basel
- 4056 Basel
- Switzerland
| | | |
Collapse
|
19
|
Odella E, Mora SJ, Wadsworth BL, Huynh MT, Goings JJ, Liddell PA, Groy TL, Gervaldo M, Sereno LE, Gust D, Moore TA, Moore GF, Hammes-Schiffer S, Moore AL. Controlling Proton-Coupled Electron Transfer in Bioinspired Artificial Photosynthetic Relays. J Am Chem Soc 2018; 140:15450-15460. [DOI: 10.1021/jacs.8b09724] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Emmanuel Odella
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, United States
| | - S. Jimena Mora
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, United States
| | - Brian L. Wadsworth
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, United States
| | - Mioy T. Huynh
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Joshua J. Goings
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Paul A. Liddell
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, United States
| | - Thomas L. Groy
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, United States
| | - Miguel Gervaldo
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Agencia Postal No. 3, 5800 Río Cuarto, Córdoba, Argentina
| | - Leónides E. Sereno
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Agencia Postal No. 3, 5800 Río Cuarto, Córdoba, Argentina
| | - Devens Gust
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, United States
| | - Thomas A. Moore
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, United States
| | - Gary F. Moore
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Ana L. Moore
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287-1604, United States
| |
Collapse
|