1
|
Clarke CJ, Verlet JRR. Dynamics of Anions: From Bound to Unbound States and Everything In Between. Annu Rev Phys Chem 2024; 75:89-110. [PMID: 38277700 DOI: 10.1146/annurev-physchem-090722-125031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2024]
Abstract
Gas-phase anions present an ideal playground for the exploration of excited-state dynamics. They offer control in terms of the mass, extent of solvation, internal temperature, and conformation. The application of a range of ion sources has opened the field to a vast array of anionic systems whose dynamics are important in areas ranging from biology to star formation. Here, we review recent experimental developments in the field of anion photodynamics, demonstrating the detailed insight into photodynamical and electron-capture processes that can be uncovered. We consider the electronic and nuclear ultrafast dynamics of electronically bound excited states along entire reaction coordinates; electronically unbound states showing that photochemical concepts, such as chromophores and Kasha's rule, are transferable to electron-driven chemistry; and nonvalence states that straddle the interface between bound and unbound states. Finally, we consider likely developments that are sure to keep the field of anion dynamics buoyant and impactful.
Collapse
Affiliation(s)
- Connor J Clarke
- Department of Chemistry, Durham University, Durham, United Kingdom;
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham, United Kingdom;
| |
Collapse
|
2
|
Abma G, Parkes MA, Razmus WO, Zhang Y, Wyatt AS, Springate E, Chapman RT, Horke DA, Minns RS. Direct Observation of a Roaming Intermediate and Its Dynamics. J Am Chem Soc 2024; 146:12595-12600. [PMID: 38682306 PMCID: PMC11082896 DOI: 10.1021/jacs.4c01543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 05/01/2024]
Abstract
Chemical reactions are often characterized by their transition state, which defines the critical geometry the molecule must pass through to move from reactants to products. Roaming provides an alternative picture, where in a dissociation reaction, the bond breaking is frustrated and a loosely bound intermediate is formed. Following bond breaking, the two partners are seen to roam around each other at distances of several Ångstroms, forming a loosely bound, and structurally ill-defined, intermediate that can subsequently lead to reactive or unreactive collisions. Here, we present a direct and time-resolved experimental measurement of roaming. By measuring the photoelectron spectrum of UV-excited acetaldehyde with a femtosecond extreme ultraviolet pulse, we captured spectral signatures of all of the key reactive structures, including that of the roaming intermediate. This provided a direct experimental measurement of the roaming process and allowed us to identify the time scales by which the roaming intermediate is formed and removed and the electronic potential surfaces upon which roaming proceeds.
Collapse
Affiliation(s)
- Grite
L. Abma
- Institute
for Molecules and Materials, Radboud University, Heijendaalseweg 135, Nijmegen 6525 AJ, The Netherlands
| | - Michael A. Parkes
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
| | - Weronika O. Razmus
- School
of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K.
| | - Yu Zhang
- Central
Laser Facility, STFC Rutherford Appleton
Laboratory, Didcot, Oxfordshire OX11 0QX, U.K.
| | - Adam S. Wyatt
- Central
Laser Facility, STFC Rutherford Appleton
Laboratory, Didcot, Oxfordshire OX11 0QX, U.K.
| | - Emma Springate
- Central
Laser Facility, STFC Rutherford Appleton
Laboratory, Didcot, Oxfordshire OX11 0QX, U.K.
| | - Richard T. Chapman
- Central
Laser Facility, STFC Rutherford Appleton
Laboratory, Didcot, Oxfordshire OX11 0QX, U.K.
| | - Daniel A. Horke
- Institute
for Molecules and Materials, Radboud University, Heijendaalseweg 135, Nijmegen 6525 AJ, The Netherlands
| | - Russell S. Minns
- School
of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K.
| |
Collapse
|
3
|
Zhao L, Geng X, Han G, Guo Y, Liu R, Chen J. Revealing the excited-state dynamics of cytidine and the role of excited-state proton transfer process. Phys Chem Chem Phys 2023; 25:32002-32009. [PMID: 37975722 DOI: 10.1039/d3cp03683a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The high photostability of DNAs and RNAs is inextricably related to the photochemical and photophysical properties of their building blocks, nucleobases and nucleosides, which can dissipate the absorbed UV light energy in a harmless manner. The deactivation mechanism of the nucleosides, especially the decay pathways of cytidine (Cyd), has been a matter of intense debate. In the current study, we employ high-level electronic structure calculations combined with excited state non-adiabatic dynamic simulations to provide a clear picture of the excited state deactivation of Cyd in both gas phase and aqueous solution. In both environments, a barrierless decay path driven by the ring-puckering motion and a relaxation channel with a small energy barrier driven by the elongation motion of CO bond are assigned to <200 fs and sub-picosecond decay time component, respectively. The presence of ribose group has a subtle effect on the dynamic behavior of Cyd in gas phase as the ribose-to-base hydrogen/proton transfer process is energetically inaccessible with a sizable energy barrier of about 1.4 eV. However, this energy barrier is significantly reduced in water, especially when an explicit water molecule is present. Therefore, we argue that the long-lived decay channel found in aqueous solution could be assigned to the Cyd-water intermolecular hydrogen/proton transfer process. The present study postulates a novel scenario toward deep understanding the intrinsic photostability of DNAs and RNAs and provides solid evidence to disclose the long history debate of cytidine excited-state decay mechanism, especially for the assignment of experimentally observed time components.
Collapse
Affiliation(s)
- Li Zhao
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China.
| | - Xuehui Geng
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China.
| | - Guoxia Han
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China.
| | - Yahui Guo
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China.
| | - Runze Liu
- Institute of Molecular Sciences and Engineering, Shandong University, Qingdao 266235, P. R. China
| | - Junsheng Chen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 KøbenhavnØ, Denmark.
| |
Collapse
|
4
|
Chien TE, Hohmann L, Harding DJ. Near-ambient pressure velocity map imaging. J Chem Phys 2022; 157:034201. [DOI: 10.1063/5.0098495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We present a new velocity map imaging instrument for studying molecular beam surface scattering in a near-ambient pressure (NAP-VMI) environment. The instrument offers the possibility to study chemical reaction dynamics and kinetics where higher pressures are either desired or unavoidable, adding a new tool to help close the “pressure gap” between surface science and applied catalysis. NAP-VMI conditions are created by two sets of ion optics that guide ions through an aperture and map their velocities. The aperture separates the high pressure ionization region and maintains the necessary vacuum in the detector region. The performance of the NAP-VMI is demonstrated with results from N2O photodissociation and N2 scattering from a Pd(110) surface, which are compared under vacuum and at near-ambient pressure (1 × 10−3 mbar). NAP-VMI has the potential to be applied to, and useful for, a broader range of experiments, including photoelectron spectroscopy and scattering with liquid microjets.
Collapse
Affiliation(s)
- Tzu-En Chien
- Department of Chemical Engineering, KTH Royal Institute of Technology, Stockholm 100 44, Sweden
| | - Lea Hohmann
- Department of Chemical Engineering, KTH Royal Institute of Technology, Stockholm 100 44, Sweden
| | - Dan J. Harding
- Department of Chemical Engineering, KTH Royal Institute of Technology, Stockholm 100 44, Sweden
| |
Collapse
|
5
|
Makurat S, Yuan Q, Czub J, Chomicz-Mańka L, Cao W, Wang XB, Rak J. Guanosine Dianions Hydrated by One to Four Water Molecules. J Phys Chem Lett 2022; 13:3230-3236. [PMID: 35380844 PMCID: PMC9014458 DOI: 10.1021/acs.jpclett.2c00512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 03/29/2022] [Indexed: 06/14/2023]
Abstract
Intermolecular interactions such as those present in molecule···water complexes may profoundly influence the physicochemical properties of molecules. Here, we carried out an experimental-computational study on doubly deprotonated guanosine monophosphate···water clusters, [dGMP - 2H]2-·nH2O (n = 1-4), using a combination of negative anion photoelectron spectroscopy (NIPES) with molecular dynamics (MD) and quantum chemical (QM) calculations. Successive addition of water molecules to [dGMP - 2H]2- increases the experimental adiabatic detachment (ADE) and vertical detachment energy (VDE) by 0.5-0.1 eV, depending on the cluster size. In order to choose the representative conformations, we combined MD simulations with a clustering procedure to identify low energy geometries for which ADEs and VDEs were computed at the CAM-B3LYP/6-31++G(d,p) level. Our results demonstrate that the assumed approach leads to sound geometries and energetics of the studied microsolvates since the calculated ADEs and VDEs are in pretty good agreement with the experimental characteristics. The evolution of hydrogen bonding with cluster size indicates the possibility of the occurrence of proton transfer for clusters comprising a larger number of water molecules.
Collapse
Affiliation(s)
- Samanta Makurat
- Faculty
of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Qinqin Yuan
- Physical
Sciences Division, Pacific Northwest National
Laboratory, Richland, Washington 99352, United States
- Department
of Chemistry, Anhui University, Hefei, Anhui 230601, China
| | - Jacek Czub
- Department
of Physical Chemistry, Gdańsk University
of Technology, Narutowicza
11/12, Gdańsk 80-233, Poland
- BioTechMed
Center, Gdańsk University of Technology, Narutowicza 11/12, Gdańsk 80-233, Poland
| | - Lidia Chomicz-Mańka
- Faculty
of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Wenjin Cao
- Physical
Sciences Division, Pacific Northwest National
Laboratory, Richland, Washington 99352, United States
| | - Xue-Bin Wang
- Physical
Sciences Division, Pacific Northwest National
Laboratory, Richland, Washington 99352, United States
| | - Janusz Rak
- Faculty
of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| |
Collapse
|
6
|
Yuan Q, Chomicz-Mańka L, Makurat S, Cao W, Rak J, Wang XB. Photoelectron Spectroscopy and Theoretical Investigations of Gaseous Doubly Deprotonated 2'-Deoxynucleoside 5'-Monophosphate Dianions. J Phys Chem Lett 2021; 12:9463-9469. [PMID: 34558897 DOI: 10.1021/acs.jpclett.1c02678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A better understanding of the mechanism of oxidative DNA damage requires obtaining a molecular level description of nucleotides in various charge states. Herein, we report a systematic photoelectron spectroscopy and theoretical investigation of the electronic and geometric structures of four doubly deprotonated 2'-deoxynucleoside 5'-monophosphate dianions, the smallest quintessential DNA building block. These dianions are intrinsically stable with their adiabatic/vertical detachment energies (ADE/VDE) ranging from 0.85/1.07 (A) and 1.05/1.30 (G) to 1.20/1.50 (C) and 1.80/2.10 eV (T). The repulsive Coulomb barrier against electron detachment is 2.0 eV for purines and 2.5 eV for pyrimidines. Dianions are deprotonated at the phosphate group and the amino group of a nucleobase. The π-type HOMO orbital resides on the nucleobase moiety for each dianion. This spatial distribution of HOMO suggests that the most loosely bound electron is detached along the direction perpendicular to the nucleobase. When combined with the previous results, this work makes complete the depiction of basic building blocks of DNA at the molecular level.
Collapse
Affiliation(s)
- Qinqin Yuan
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Lidia Chomicz-Mańka
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Samanta Makurat
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Wenjin Cao
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Janusz Rak
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, Gdańsk 80-308, Poland
| | - Xue-Bin Wang
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| |
Collapse
|
7
|
Castellani ME, Verlet JRR. Intramolecular Photo-Oxidation as a Potential Source to Probe Biological Electron Damage: A Carboxylated Adenosine Analogue as Case Study. Molecules 2021; 26:2877. [PMID: 34067988 PMCID: PMC8152231 DOI: 10.3390/molecules26102877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/05/2021] [Accepted: 05/10/2021] [Indexed: 11/16/2022] Open
Abstract
A carboxylated adenosine analog (C-Ado-) has been synthesized and probed via time-resolved photoelectron spectroscopy in order to induce intra-molecular charge transfer from the carboxylic acid moiety to the nucleobase. Intra-molecular charge transfer can be exploited as starting point to probe low-energy electron (LEE) damage in DNA and its derivatives. Time-dependent density functional theory (TD-DFT) calculations at the B3LYP-6311G level of theory have been performed to verify that the highest occupied molecular orbital (HOMO) was located on carboxylic acid and that the lowest occupied molecular orbital (LUMO) was on the nucleobase. Hence, the carboxylic acid could work as electron source, whilst the nucleobase could serve the purpose of electron acceptor. The dynamics following excitation at 4.66 eV (266 nm) were probed using time-resolved photoelectron spectroscopy using probes at 1.55 eV (800 nm) and 3.10 eV (400 nm). The data show rapid decay of the excited state population and, based on the similarity of the overall dynamics to deoxy-adenosine monophosphate (dAMP-), it appears that the dominant decay mechanism is internal conversion following 1ππ* excitation of the nucleobase, rather than charge-transfer from the carboxylic acid to the nucleobase.
Collapse
|
8
|
Castellani ME, Avagliano D, Verlet JRR. Ultrafast Dynamics of the Isolated Adenosine-5'-triphosphate Dianion Probed by Time-Resolved Photoelectron Imaging. J Phys Chem A 2021; 125:3646-3652. [PMID: 33882670 DOI: 10.1021/acs.jpca.1c01646] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The excited state dynamics of the doubly deprotonated dianion of adenosine-5'-triphosphate, [ATP-H2]2-, has been spectroscopically explored by time-resolved photoelectron spectroscopy following excitation at 4.66 eV. Time-resolved photoelectron spectra show that two competing processes occur for the initially populated 1ππ* state. The first is rapid electron emission by tunneling through a repulsive Coulomb barrier as the 1ππ* state is a resonance. The second is nuclear motion on the 1ππ* state surface leading to an intermediate that no longer tunnels and subsequently decays by internal conversion to the ground electronic state. The spectral signatures of the features are similar to those observed for other adenine-derivatives, suggesting that this nucleobase is quite insensitive to the nearby negative charges localized on the phosphates, except of course for the appearance of the additional electron tunneling channel, which is open in the dianion.
Collapse
Affiliation(s)
| | - Davide Avagliano
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Strasse 17 1090 Vienna, Austria
| | - Jan R R Verlet
- Department of Chemistry, Durham University, DH1 3LE Durham, U.K
| |
Collapse
|
9
|
Castellani ME, Avagliano D, González L, Verlet JRR. Site-Specific Photo-oxidation of the Isolated Adenosine-5'-triphosphate Dianion Determined by Photoelectron Imaging. J Phys Chem Lett 2020; 11:8195-8201. [PMID: 32886886 DOI: 10.1021/acs.jpclett.0c02089] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Photoelectron imaging of the isolated adenosine-5'-triphosphate dianion excited to the 1ππ* states reveals that electron emission is predominantly parallel to the polarization axis of the light and arises from subpicosecond electron tunneling through the repulsive Coulomb barrier (RCB). The computed RCB shows that the most probable electron emission site is on the amino group of adenine. This is consistent with the photoelectron imaging: excitation to the 1ππ* states leads to an aligned ensemble distributed predominantly parallel to the long axis of adenine; the subsequent electron tunneling site is along this axis; and the negatively charged phosphate groups guide the outgoing electron mostly along this axis at long range. Imaging of electron tunneling from polyanions combined with computational chemistry may offer a general route for probing the intrinsic photo-oxidation site and dynamics as well as the overall structure of complex isolated species.
Collapse
Affiliation(s)
| | - Davide Avagliano
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna, Austria
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| |
Collapse
|
10
|
Abiola TT, Whittock AL, Stavros VG. Unravelling the Photoprotective Mechanisms of Nature-Inspired Ultraviolet Filters Using Ultrafast Spectroscopy. Molecules 2020; 25:E3945. [PMID: 32872380 PMCID: PMC7504748 DOI: 10.3390/molecules25173945] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 02/07/2023] Open
Abstract
There are several drawbacks with the current commercially available ultraviolet (UV) filters used in sunscreen formulations, namely deleterious human and ecotoxic effects. As a result of the drawbacks, a current research interest is in identifying and designing new UV filters. One approach that has been explored in recent years is to use nature as inspiration, which is the focus of this review. Both plants and microorganisms have adapted to synthesize their own photoprotective molecules to guard their DNA from potentially harmful UV radiation. The relaxation mechanism of a molecule after it has been photoexcited can be unravelled by several techniques, the ones of most interest for this review being ultrafast spectroscopy and computational methods. Within the literature, both techniques have been implemented on plant-, and microbial-inspired UV filters to better understand their photoprotective roles in nature. This review aims to explore these findings for both families of nature-inspired UV filters in the hope of guiding the future design of sunscreens.
Collapse
Affiliation(s)
- Temitope T. Abiola
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK; (T.T.A.); (A.L.W.)
| | - Abigail L. Whittock
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK; (T.T.A.); (A.L.W.)
- AS CDT, Senate House, University of Warwick, Coventry CV4 7AL, UK
| | - Vasilios G. Stavros
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK; (T.T.A.); (A.L.W.)
| |
Collapse
|
11
|
Bouakil M, Chirot F, Girod M, Dugourd P, MacAleese L. Secondary structure effects on internal proton transfer in poly-peptides. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:024302. [PMID: 32232075 PMCID: PMC7100371 DOI: 10.1063/4.0000003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 02/21/2020] [Indexed: 12/21/2022]
Abstract
A pump-probe approach was designed to determine the internal proton transfer (PT) rate in a series of poly-peptide radical cations containing both histidine and tryptophan. The proton transfer is driven by the gas-phase basicity difference between residues. The fragmentation scheme indicates that the gas-phase basicity of histidine is lower than that of radical tryptophan so that histidine is always pulling the proton away from tryptophan. However, the proton transfer requires the two basic sites to be in close proximity, which is rate limited by the peptide conformational dynamics. PT rate measurements were used to probe and explore the peptide conformational dynamics in several poly-glycines/prolines/alanines. For small and unstructured peptides, the PT rate decreases with the size, as expected from a statistical point of view in a flat conformational space. Conversely, if structured conformations are accessible, the structural flexibility of the peptide is decreased. This slows down the occurrence of conformations favorable to proton transfer. A dramatic decrease in the PT rates was observed for peptides HAnW, when n changes from 5 to 6. This is attributed to the onset of a stable helix for n = 6. No such discontinuity is observed for poly-glycines or poly-prolines. In HAnW, the gas-phase basicity and helix propensity compete for the position of the charge. Interestingly, in this competition between PT and helix formation in HA6W, the energy gain associated with helix formation is large enough to slow down the PT beyond experimental time but does not ultimately prevail over the proton preference for histidine.
Collapse
Affiliation(s)
- M Bouakil
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Lyon, France
| | - F Chirot
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut des Sciences Analytiques, F-69622 Lyon, France
| | - M Girod
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut des Sciences Analytiques, F-69622 Lyon, France
| | - P Dugourd
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Lyon, France
| | - L MacAleese
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Lyon, France
| |
Collapse
|
12
|
Pepino AJ, Segarra-Martí J, Nenov A, Rivalta I, Improta R, Garavelli M. UV-induced long-lived decays in solvated pyrimidine nucleosides resolved at the MS-CASPT2/MM level. Phys Chem Chem Phys 2018; 20:6877-6890. [PMID: 29459916 DOI: 10.1039/c7cp08235e] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The most relevant 'dark' electronic excited states in DNA/RNA pyrimidine nucleosides are mapped in water employing hybrid MS-CASPT2/MM optimisations with explicit solvation and including the sugar. Conical intersections (CIs) between initially accessed bright 1ππ* and the lowest energy dark 1nπ* excited states, involving the lone pair localised on the oxygen and/or nitrogen atoms are characterised. They are found in the vicinities of the Franck-Condon (FC) region and are shown to facilitate non-adiabatic population transfer. The excited state population of the 1nOπ* state, localised in the carbonyl moiety on all pyrimidine nucleosides, is predicted to rapidly evolve to its minimum, displaying non-negligible potential energy barriers along its non-radiative decay, and accounting for the ps signal registered in pump-probe experiments as well as for an efficient population of the triplet state. Cytidine displays an additional 1nNπ* state localised in the N3 atom and that leads to its excited state minimum displaying large potential energy barriers in the pathway connecting to the CI with the ground state. Sugar-to-base hydrogen/proton transfer processes are assessed in solution for the first time, displaying a sizable barrier along its decay and thus being competitive with other slow decay channels in the ps and ns timescales. A unified deactivation scheme for the long-lived channels of pyrimidine nucleosides is delivered, where the 1nOπ* state is found to mediate the long-lived decay in the singlet manifold and act as the doorway for triplet population and thus accounting for the recorded phosphorescence and, more generally, for the transient/photoelectron spectral signals registered up to the ns timescale.
Collapse
Affiliation(s)
- Ana Julieta Pepino
- Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy.
| | | | | | | | | | | |
Collapse
|
13
|
Conti I, Garavelli M. Evolution of the Excitonic State of DNA Stacked Thymines: Intrabase ππ* → S 0 Decay Paths Account for Ultrafast (Subpicosecond) and Longer (>100 ps) Deactivations. J Phys Chem Lett 2018; 9:2373-2379. [PMID: 29668287 DOI: 10.1021/acs.jpclett.8b00698] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Monomer-like ring puckering decay paths for two stacked quantum mechanical thymines inside a solvated DNA duplex described at the molecular mechanics level are mapped using a hybrid CASPT2//CASSCF/MM protocol that accounts for steric, electronic and electrostatic interactions within the nucleobases native environment. Asymmetric stacking between nucleobases open ups different intrabase ππ* decay paths accounting for distinctive excited state lifetimes, spanning the subps to subns time window.
Collapse
Affiliation(s)
- Irene Conti
- Dipartimento di Chimica Industriale "Toso Montanari" , Università di Bologna , Viale del Risorgimento 4 , I-40136 Bologna , Italy
| | - Marco Garavelli
- Dipartimento di Chimica Industriale "Toso Montanari" , Università di Bologna , Viale del Risorgimento 4 , I-40136 Bologna , Italy
| |
Collapse
|
14
|
Roy A, Seidel R, Kumar G, Bradforth SE. Exploring Redox Properties of Aromatic Amino Acids in Water: Contrasting Single Photon vs Resonant Multiphoton Ionization in Aqueous Solutions. J Phys Chem B 2018. [DOI: 10.1021/acs.jpcb.7b11762] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anirban Roy
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Robert Seidel
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Gaurav Kumar
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Stephen E. Bradforth
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| |
Collapse
|
15
|
Baker LA, Marchetti B, Karsili TNV, Stavros VG, Ashfold MNR. Photoprotection: extending lessons learned from studying natural sunscreens to the design of artificial sunscreen constituents. Chem Soc Rev 2018; 46:3770-3791. [PMID: 28580469 DOI: 10.1039/c7cs00102a] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Evolution has ensured that plants and animals have developed effective protection mechanisms against the potentially harmful effects of incident ultraviolet radiation (UVR). Tanning is one such mechanism in humans, but tanning only occurs post-exposure to UVR. Hence, there is ever growing use of commercial sunscreens to pre-empt overexposure to UVR. Key requirements for any chemical filter molecule used in such a photoprotective capacity include a large absorption cross-section in the UV-A and UV-B spectral regions and the availability of one or more mechanisms whereby the absorbed photon energy can be dissipated without loss of the molecular integrity of the chemical filter. Here we summarise recent experimental (mostly ultrafast pump-probe spectroscopy studies) and computational progress towards unravelling various excited state decay mechanisms that afford the necessary photostability in chemical filters found in nature and those used in commercial sunscreens. We also outline ways in which a better understanding of the photophysics and photochemistry of sunscreen molecules selected by nature could aid the design of new and improved commercial sunscreen formulations.
Collapse
Affiliation(s)
- Lewis A Baker
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
| | - Barbara Marchetti
- Department of Chemistry, University of Pennsylvania, Philadelphia, USA
| | | | - Vasilios G Stavros
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK.
| | - Michael N R Ashfold
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
| |
Collapse
|
16
|
Kowalewski M, Fingerhut BP, Dorfman KE, Bennett K, Mukamel S. Simulating Coherent Multidimensional Spectroscopy of Nonadiabatic Molecular Processes: From the Infrared to the X-ray Regime. Chem Rev 2017; 117:12165-12226. [DOI: 10.1021/acs.chemrev.7b00081] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Markus Kowalewski
- Department
of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697-2025, United States
| | - Benjamin P. Fingerhut
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - Konstantin E. Dorfman
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Kochise Bennett
- Department
of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697-2025, United States
| | - Shaul Mukamel
- Department
of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697-2025, United States
| |
Collapse
|
17
|
Ashwood B, Ortiz-Rodríguez LA, Crespo-Hernández CE. Excited-State Dynamics in O 6-Methylguanosine: Impact of O 6-Methylation on the Relaxation Mechanism of Guanine Monomers. J Phys Chem Lett 2017; 8:4380-4385. [PMID: 28850232 DOI: 10.1021/acs.jpclett.7b02090] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Absorption of ultraviolet radiation by DNA bases results in ultrafast internal conversion to the ground state, which minimizes photodamage. However, exogenous and endogenous alkylating agents present in the cellular environment can methylate the nucleobases in DNA. In particular, methylation of guanosine at the O6 position in DNA leads to the formation of the O6-methylguanosine adduct, which may alter the photostability of DNA. This contribution demonstrates that O6-methylation of guanosine red shifts its ground-state absorption spectrum and slows down the rate of internal conversion to the ground state by ∼40-fold in aqueous solution. The 40-fold decrease in the rate of excited-state decay increases the probability of photodamage within cellular DNA. It is proposed that the longer decay lifetime corresponds to relaxation of the excited-state population in O6-methylguanosine along a C6-puckered reaction coordinate in the 1ππ*(La) potential energy surface that runs parallel to an ultrafast internal conversion pathway along a C2-puckered coordinate.
Collapse
Affiliation(s)
- Brennan Ashwood
- Department of Chemistry and Center for Chemical Dynamics, Case Western Reserve University , Cleveland, Ohio 44106, United States
| | - Luis A Ortiz-Rodríguez
- Department of Chemistry and Center for Chemical Dynamics, Case Western Reserve University , Cleveland, Ohio 44106, United States
| | - Carlos E Crespo-Hernández
- Department of Chemistry and Center for Chemical Dynamics, Case Western Reserve University , Cleveland, Ohio 44106, United States
| |
Collapse
|
18
|
Staniforth M, Quan WD, Karsili TNV, Baker LA, O’Reilly RK, Stavros VG. First Step toward a Universal Fluorescent Probe: Unravelling the Photodynamics of an Amino–Maleimide Fluorophore. J Phys Chem A 2017; 121:6357-6365. [DOI: 10.1021/acs.jpca.7b04702] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Michael Staniforth
- Department
of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - Wen-Dong Quan
- Department
of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
- Molecular
Organization and Assembly of Cells Doctoral Training Centre, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - Tolga N. V. Karsili
- Department
of Chemistry, Technische Universität München, Lichtenbergstrasse
4, 85747 Garching, Germany
| | - Lewis A. Baker
- Department
of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
- Molecular
Organization and Assembly of Cells Doctoral Training Centre, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - Rachel K. O’Reilly
- Department
of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - Vasilios G. Stavros
- Department
of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| |
Collapse
|
19
|
Martínez-Fernández L, Pepino AJ, Segarra-Martí J, Jovaišaitė J, Vaya I, Nenov A, Markovitsi D, Gustavsson T, Banyasz A, Garavelli M, Improta R. Photophysics of Deoxycytidine and 5-Methyldeoxycytidine in Solution: A Comprehensive Picture by Quantum Mechanical Calculations and Femtosecond Fluorescence Spectroscopy. J Am Chem Soc 2017; 139:7780-7791. [DOI: 10.1021/jacs.7b01145] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- L. Martínez-Fernández
- Istituto di Biostrutture e Bioimmagini,
CNR, Via Mezzocannone 16, I-80134 Napoli, Italy
| | - A. J. Pepino
- Dipartimento di Chimica Industriale “T. Montanari”, Università di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - J. Segarra-Martí
- Laboratoire de Chimie UMR 5182, Univ Lyon, ENS de Lyon, CNRS, Université Lyon 1, F-69342 Lyon, France
| | - J. Jovaišaitė
- LIDYL, CEA, CNRS, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - I. Vaya
- LIDYL, CEA, CNRS, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - A. Nenov
- Dipartimento di Chimica Industriale “T. Montanari”, Università di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - D. Markovitsi
- LIDYL, CEA, CNRS, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - T. Gustavsson
- LIDYL, CEA, CNRS, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - A. Banyasz
- LIDYL, CEA, CNRS, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - M. Garavelli
- Dipartimento di Chimica Industriale “T. Montanari”, Università di Bologna, Viale Risorgimento 4, I-40136 Bologna, Italy
| | - R. Improta
- Istituto di Biostrutture e Bioimmagini,
CNR, Via Mezzocannone 16, I-80134 Napoli, Italy
- LIDYL, CEA, CNRS, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| |
Collapse
|
20
|
Cercola R, Matthews E, Dessent CEH. Photoexcitation of Adenosine 5'-Triphosphate Anions in Vacuo: Probing the Influence of Charge State on the UV Photophysics of Adenine. J Phys Chem B 2017; 121:5553-5561. [PMID: 28521097 DOI: 10.1021/acs.jpcb.7b03435] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report the first UV laser photodissociation spectra (4.0-5.8 eV) of gas-phase deprotonated adenosine 5'-triphosphate, diphosphate and monophosphate anions. The photodepletion spectra of these anions display strong absorption bands across the region of 4.6-5.2 eV, consistent with excitation of a primarily adenine-centered π-π* transition. The spectra appear insensitive to the charge of the species (i.e., the spectrum of [ATP-2H]2- closely resembles that of [ATP-H]-), while the spectral profile is affected to a greater extent by the variation of the molecular structure, i.e. the [AMP-H]- and [ADP-H]- photodepletion spectra display similar profiles while the [ATP-H]- spectrum is distinctive. The photodepletion cross-section also decreases for the ATP anions compared to both the AMP and ADP anions, reflecting a high intrinsic photostability of ATP versus both AMP and ADP. A range of photofragments are produced across the 4.0-5.8 eV spectral range for all of the ATP analogues studied. These fragments are primarily associated with fragmentation on the ground-state electronic surface, indicative of a statistical decay process where ultrafast decay is followed by ergodic dissociation. However, while the photofragments observed following photoexcitation of the monoanionic species, [AMP-H]- to [ADP-H]- to [ATP-H]- are entirely consistent with statistical decay, an additional group of photofragments are observed for the dianionic species, [ADP-2H]2- and [ATP-2H]2-, that we associate with electron detachment, and subsequent fragmentation of the resulting electron-detached photofragment. TDDFT calculations are presented to support the interpretation of the experimental data, and confirm that the electronic structure of the adenine moiety is relatively unperturbed by varying the overall charge.
Collapse
Affiliation(s)
- Rosaria Cercola
- Department of Chemistry, University of York , Heslington, York, YO10 5DD, U.K
| | - Edward Matthews
- Department of Chemistry, University of York , Heslington, York, YO10 5DD, U.K
| | | |
Collapse
|
21
|
Baker LA, Clark SL, Habershon S, Stavros VG. Ultrafast Transient Absorption Spectroscopy of the Sunscreen Constituent Ethylhexyl Triazone. J Phys Chem Lett 2017; 8:2113-2118. [PMID: 28437110 DOI: 10.1021/acs.jpclett.7b00633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The ultrafast photoprotection mechanisms in operation in ethylhexyl triazone (EHT, octyl triazone), an approved ultraviolet-B (UV-B) chemical filter for commercial sunscreens, remain elusive, with a notable absence of ultrafast time-resolved measurements. These large organic molecules are of increasing interest as they are suspected to be less likely to penetrate the skin than some of the smaller approved filters, thereby reducing the possible adverse effects from sunscreen products. We apply femtosecond transient absorption spectroscopy with electronic structure calculations to unravel the complete photodeactivation mechanism that EHT undergoes after UV-B irradiation. We propose that this involves ultrafast internal conversion of the initially photoexcited n1ππ* state that couples to the ground state via a 11ππ*/S0 conical intersection, enabling multiple absorption and recovery cycles, as one would anticipate from a highly efficient filter. We also observe long-lived photoproducts which, based on previous studies along with present electronic structure calculations, we attribute to trapped excited populations in the S1 and T1 states.
Collapse
Affiliation(s)
- Lewis A Baker
- Department of Chemistry and ‡Centre for Scientific Computing, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - Sarah L Clark
- Department of Chemistry and ‡Centre for Scientific Computing, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - Scott Habershon
- Department of Chemistry and ‡Centre for Scientific Computing, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - Vasilios G Stavros
- Department of Chemistry and ‡Centre for Scientific Computing, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| |
Collapse
|
22
|
Pepino AJ, Segarra-Martí J, Nenov A, Improta R, Garavelli M. Resolving Ultrafast Photoinduced Deactivations in Water-Solvated Pyrimidine Nucleosides. J Phys Chem Lett 2017; 8:1777-1783. [PMID: 28346789 DOI: 10.1021/acs.jpclett.7b00316] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
For the first time, ultrafast deactivations of photoexcited water-solvated pyrimidine nucleosides are mapped employing hybrid QM(CASPT2)/MM(AMBER) optimizations that account for explicit solvation, sugar effects, and dynamically correlated potential energy surfaces. Low-energy S1/S0 ring-puckering and ring-opening conical intersections (CIs) are suggested to drive the ballistic coherent subpicosecond (<200 fs) decays observed in each pyrimidine, the energetics controlling this processes correlating with the lifetimes observed. A second bright 1π2π* state, promoting excited-state population branching and leading toward a third CI with the ground state, is proposed to be involved in the slower ultrafast decay component observed in Thd/Cyd. The transient spectroscopic signals of the competitive deactivation channels are computed for the first time. A general unified scheme for ultrafast deactivations, spanning the sub- to few-picosecond time domain, is eventually delivered, with computed data that matches the experiments and elucidates the intrinsic photoprotection mechanism in solvated pyrimidine nucleosides.
Collapse
Affiliation(s)
- Ana Julieta Pepino
- Dipartimento di Chimica Industriale "Toso Montanari" Viale del Risorgimento, 4, 40136 Bologna, Italy
| | - Javier Segarra-Martí
- Laboratoire de Chimie UMR 5182, Université Lyon, ENS de Lyon, CNRS, Université Lyon 1 , F-69342 Lyon, France
| | - Artur Nenov
- Dipartimento di Chimica Industriale "Toso Montanari" Viale del Risorgimento, 4, 40136 Bologna, Italy
| | - Roberto Improta
- Istituto di Biostrutture e Bioimmagini CNR , Via Mezzocannone 16, I-80134 Napoli, Italy
| | - Marco Garavelli
- Dipartimento di Chimica Industriale "Toso Montanari" Viale del Risorgimento, 4, 40136 Bologna, Italy
- Laboratoire de Chimie UMR 5182, Université Lyon, ENS de Lyon, CNRS, Université Lyon 1 , F-69342 Lyon, France
| |
Collapse
|
23
|
Segarra-Martí J, Francés-Monerris A, Roca-Sanjuán D, Merchán M. Assessment of the Potential Energy Hypersurfaces in Thymine within Multiconfigurational Theory: CASSCF vs. CASPT2. Molecules 2016; 21:molecules21121666. [PMID: 27918489 PMCID: PMC6274573 DOI: 10.3390/molecules21121666] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 11/30/2016] [Accepted: 12/01/2016] [Indexed: 11/16/2022] Open
Abstract
The present study provides new insights into the topography of the potential energy hypersurfaces (PEHs) of the thymine nucleobase in order to rationalize its main ultrafast photochemical decay paths by employing two methodologies based on the complete active space self-consistent field (CASSCF) and the complete active space second-order perturbation theory (CASPT2) methods: (i) CASSCF optimized structures and energies corrected with the CASPT2 method at the CASSCF geometries and (ii) CASPT2 optimized geometries and energies. A direct comparison between these strategies is drawn, yielding qualitatively similar results within a static framework. A number of analyses are performed to assess the accuracy of these different computational strategies under study based on a variety of numerical thresholds and optimization methods. Several basis sets and active spaces have also been calibrated to understand to what extent they can influence the resulting geometries and subsequent interpretation of the photochemical decay channels. The study shows small discrepancies between CASSCF and CASPT2 PEHs, displaying a shallow planar or twisted 1(ππ*) minimum, respectively, and thus featuring a qualitatively similar scenario for supporting the ultrafast bi-exponential deactivation registered in thymine upon UV-light exposure. A deeper knowledge of the PEHs at different levels of theory provides useful insight into its correct characterization and subsequent interpretation of the experimental observations. The discrepancies displayed by the different methods studied here are then discussed and framed within their potential consequences in on-the-fly non-adiabatic molecular dynamics simulations, where qualitatively diverse outcomes are expected.
Collapse
Affiliation(s)
- Javier Segarra-Martí
- Instituto de Ciencia Molecular, Universitat de València, P. O. Box 22085, ES-46071 Valencia, Spain.
- Present Address: Laboratoire de Chimie UMR 5182, École Normale Supérieure de Lyon, CNRS, Université de Lyon, 46 Allée d'Italie, F-69364 Lyon Cedex 07, France.
| | - Antonio Francés-Monerris
- Instituto de Ciencia Molecular, Universitat de València, P. O. Box 22085, ES-46071 Valencia, Spain.
| | - Daniel Roca-Sanjuán
- Instituto de Ciencia Molecular, Universitat de València, P. O. Box 22085, ES-46071 Valencia, Spain.
| | - Manuela Merchán
- Instituto de Ciencia Molecular, Universitat de València, P. O. Box 22085, ES-46071 Valencia, Spain.
| |
Collapse
|
24
|
Baker LA, Grosvenor LC, Ashfold MN, Stavros VG. Ultrafast photophysical studies of a multicomponent sunscreen: Oxybenzone–titanium dioxide mixtures. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.10.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
25
|
Quan WD, Pitto-Barry A, Baker LA, Stulz E, Napier R, O'Reilly RK, Stavros VG. Retaining individualities: the photodynamics of self-ordering porphyrin assemblies. Chem Commun (Camb) 2016; 52:1938-41. [PMID: 26680651 PMCID: PMC4720934 DOI: 10.1039/c5cc09095d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Retained photochemical properties – a simple porphyrin–polyDMA conjugate with the ability to self assemble into large (∼1 μm) vesicles in water. The photodynamics are remarkably preserved despite the extensive aggregation.
The retention of photochemical properties of individual chromophores is a key feature of biological light harvesting complexes. This is achieved despite extensive aggregation of the chromophores, which in synthetic chromophore assemblies often yields a change in spectral characteristics. As an alternative approach towards mimicking biological light harvesting complexes, we report the synthesis of porphyrin assemblies which retained the photochemical properties of the individual chromophore units despite their substantial aggregation. These new materials highlight a new bottom-up approach towards the design and understanding of more complex biomimetic and naturally occurring biological systems.
Collapse
Affiliation(s)
- Wen-Dong Quan
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK. and Molecular Organisation and Assembly of Cells Doctoral Training Center (MOAC DTC), University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Anaïs Pitto-Barry
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
| | - Lewis A Baker
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK. and Molecular Organisation and Assembly of Cells Doctoral Training Center (MOAC DTC), University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Eugen Stulz
- School of Chemistry & Institute for Life Sciences, University of Southampton, Highfield, Southampton, UK
| | - Richard Napier
- School of Life Science, University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Rachel K O'Reilly
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
| | - Vasilios G Stavros
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
| |
Collapse
|
26
|
Baker LA, Stavros VG. Observing and understanding the ultrafast photochemistry in small molecules: applications to sunscreens. Sci Prog 2016; 99:282-311. [PMID: 28742490 PMCID: PMC10365382 DOI: 10.3184/003685016x14684992086383] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In this review, we discuss the importance of biological and artificial photoprotection against overexposure to harmful ultraviolet radiation. Transient electronic and transient vibrational absorption spectroscopies are highlighted as important tools in understanding the energy transfer in small molecules, with a focus on the application to commercial sunscreens with representative examples given. Oxybenzone, a common ingredient in commercial sunscreens and sinapoyl malate, a biological sunscreen in plant leaves are presented as case studies.
Collapse
Affiliation(s)
- Lewis A. Baker
- University of Warwick, Mathematical Biology and Biophysical Chemistry at the University of Warwick Molecular Organisation and Assembly in Cells Doctoral Training Centre
| | - Vasilios G. Stavros
- University of Warwick, King's College London, University of California Berkeley
| |
Collapse
|
27
|
Anstöter CS, Bull JN, Verlet JR. Ultrafast dynamics of temporary anions probed through the prism of photodetachment. INT REV PHYS CHEM 2016. [DOI: 10.1080/0144235x.2016.1203522] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
28
|
Horbury MD, Baker LA, Quan WD, Greenough SE, Stavros VG. Photodynamics of potent antioxidants: ferulic and caffeic acids. Phys Chem Chem Phys 2016; 18:17691-7. [PMID: 27310931 DOI: 10.1039/c6cp01595f] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The dynamics of ferulic acid (3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid) and caffeic acid (3-(3,4-dihydroxyphenyl)-2-propenoic acid) in acetonitrile, dioxane and water at pH 2.2 following photoexcitation to the first excited singlet state are reported. These hydroxycinnamic acids display both strong ultraviolet absorption and potent antioxidant activity, making them promising sunscreen components. Ferulic and caffeic acids have previously been shown to undergo trans-cis photoisomerization via irradiation studies, yet time-resolved measurements were unable to observe formation of the cis-isomer. In the present study, we are able to observe the formation of the cis-isomer as well as provide timescales of relaxation following initial photoexcitation.
Collapse
Affiliation(s)
- Michael D Horbury
- Department of Chemistry, University of Warwick, Library Road, Coventry, CV4 7AL, UK.
| | | | | | | | | |
Collapse
|
29
|
Baker LA, Horbury MD, Stavros VG. Ultrafast photoprotective properties of the sunscreening agent octocrylene. OPTICS EXPRESS 2016; 24:10700-10709. [PMID: 27409891 DOI: 10.1364/oe.24.010700] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Today octocrylene is one of the most common molecules included in commercially available sunscreens. It provides broadband photoprotection for the skin from incident UV-A and UV-B radiation of the solar spectrum. In order to understand how octocrylene fulfils its role as a sunscreening agent, femtosecond pump-probe transient electronic UV-visible absorption spectroscopy is utilised to investigate the ultrafastnonradiative relaxation mechanism of octocrylene in cyclohexane or methanol after UV-B photoexcitation. The data presented clearly shows that UV-B photoexcited octocrylene exhibits ultrafast-nonradiative relaxation mechanisms to repopulate its initial ground state within a few picoseconds, which, at the very least, photophysically justifies its wide spread inclusion in commercial sunscreens.
Collapse
|
30
|
MacAleese L, Hermelin S, Hage KE, Chouzenoux P, Kulesza A, Antoine R, Bonacina L, Meuwly M, Wolf JP, Dugourd P. Sequential Proton Coupled Electron Transfer (PCET): Dynamics Observed over 8 Orders of Magnitude in Time. J Am Chem Soc 2016; 138:4401-7. [DOI: 10.1021/jacs.5b12587] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Luke MacAleese
- Institut
Lumière Matière, UMR5306 Université Claude Bernard
Lyon1-CNRS, Université de Lyon 69622 Villeurbanne
cedex, France
| | - Sylvain Hermelin
- Group
of Applied Physics (GAP) Biophotonics, Université de Genève, Chemin
de Pinchat 22, CH-1211 Geneva, Switzerland
| | - Krystel El Hage
- Department
of Chemistry, University of Basel, Klingelbergstr 80, CH-4056 Basel, Switzerland
| | - Pierre Chouzenoux
- Institut
Lumière Matière, UMR5306 Université Claude Bernard
Lyon1-CNRS, Université de Lyon 69622 Villeurbanne
cedex, France
| | - Alexander Kulesza
- Institut
Lumière Matière, UMR5306 Université Claude Bernard
Lyon1-CNRS, Université de Lyon 69622 Villeurbanne
cedex, France
| | - Rodolphe Antoine
- Institut
Lumière Matière, UMR5306 Université Claude Bernard
Lyon1-CNRS, Université de Lyon 69622 Villeurbanne
cedex, France
| | - Luigi Bonacina
- Group
of Applied Physics (GAP) Biophotonics, Université de Genève, Chemin
de Pinchat 22, CH-1211 Geneva, Switzerland
| | - Markus Meuwly
- Department
of Chemistry, University of Basel, Klingelbergstr 80, CH-4056 Basel, Switzerland
| | - Jean-Pierre Wolf
- Group
of Applied Physics (GAP) Biophotonics, Université de Genève, Chemin
de Pinchat 22, CH-1211 Geneva, Switzerland
| | - Philippe Dugourd
- Institut
Lumière Matière, UMR5306 Université Claude Bernard
Lyon1-CNRS, Université de Lyon 69622 Villeurbanne
cedex, France
| |
Collapse
|
31
|
Stavros VG, Verlet JRR. Gas-Phase Femtosecond Particle Spectroscopy: A Bottom-Up Approach to Nucleotide Dynamics. Annu Rev Phys Chem 2016; 67:211-32. [PMID: 26980306 DOI: 10.1146/annurev-physchem-040215-112428] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We summarize how gas-phase ultrafast charged-particle spectroscopy has been used to provide an understanding of the photophysics of DNA building blocks. We focus on adenine and discuss how, following UV excitation, specific interactions determine the fates of its excited states. The dynamics can be probed using a systematic bottom-up approach that provides control over these interactions and that allows ever-larger complexes to be studied. Starting from a chromophore in adenine, the excited state decay mechanisms of adenine and chemically substituted or clustered adenine are considered and then extended to adenosine mono-, di-, and trinucleotides. We show that the gas-phase approach can offer exquisite insight into the dynamics observed in aqueous solution, but we also highlight stark differences. An outlook is provided that discusses some of the most promising developments in this bottom-up approach.
Collapse
Affiliation(s)
- Vasilios G Stavros
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom;
| | - Jan R R Verlet
- Department of Chemistry, University of Durham, Durham, DH1 3LE, United Kingdom;
| |
Collapse
|
32
|
Improta R, Santoro F, Blancafort L. Quantum Mechanical Studies on the Photophysics and the Photochemistry of Nucleic Acids and Nucleobases. Chem Rev 2016; 116:3540-93. [PMID: 26928320 DOI: 10.1021/acs.chemrev.5b00444] [Citation(s) in RCA: 338] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The photophysics and photochemistry of DNA is of great importance due to the potential damage of the genetic code by UV light. Quantum mechanical studies have played a key role in interpretating the results of modern time-resolved pump-probe spectroscopy, and in elucidating the main photoactivated reactive paths. This review provides a concise, complete picture of the computational studies carried out, approximately, in the past decade. We start with an overview of the photophysics of the nucleobases in the gas phase and in solution. We discuss the proposed mechanisms for ultrafast decay to the ground state, that involve conical intersections, consider the role of triplet states, and analyze how the solvent modulates the photophysics. Then we move to larger systems, from dinucleotides to single- and double-stranded oligonucleotides. We focus on the possible role of charge transfer and delocalized or excitonic states in the photophysics of these systems and discuss the main photochemical paths. We finish with an outlook on the current challenges in the field and future directions of research.
Collapse
Affiliation(s)
- Roberto Improta
- Istituto di Biostrutture Biommagini (IBB-CNR), CNR-Consiglio Nazionale delle Ricerche , Via Mezzocannone 16, I-80134, Napoli, Italy
| | - Fabrizio Santoro
- Area della Ricerca di Pisa, Istituto di Chimica dei Composti Organo Metallici (ICCOM-CNR), CNR-Consiglio Nazionale delle Ricerche , Via G. Moruzzi 1, I-56124 Pisa, Italy
| | - Lluís Blancafort
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, Campus de Montilivi , 17071 Girona, Spain
| |
Collapse
|
33
|
Baker LA, Horbury MD, Greenough SE, Allais F, Walsh PS, Habershon S, Stavros VG. Ultrafast Photoprotecting Sunscreens in Natural Plants. J Phys Chem Lett 2016; 7:56-61. [PMID: 26654715 DOI: 10.1021/acs.jpclett.5b02474] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We explore the ultrafast photoprotective properties of a series of sinapic acid derivatives in a range of solvents, utilizing femtosecond transient electronic absorption spectroscopy. We find that a primary relaxation mechanism displayed by the plant sunscreen sinapoyl malate and other related molecular species may be understood as a multistep process involving internal conversion of the initially photoexcited 1(1)ππ* state along a trans-cis photoisomerization coordinate, leading to the repopulation of the original trans ground-state isomer or the formation of a stable cis isomer.
Collapse
Affiliation(s)
| | | | | | - Florent Allais
- Chaire Agro-Biotechnologies Industrielles (ABI), AgroParisTech , F-51100 Reims, France
- UMR GMPA, AgroParisTech, INRA , F-78850 Thiverval-Grignon, France
- UMR IJPB, AgroParisTech, INRA , F-78026 Versailles, France
| | - Patrick S Walsh
- Department of Chemistry, Purdue University , West Lafayette, Indiana 47907-2084, United States
| | | | | |
Collapse
|
34
|
Matthews E, Sen A, Yoshikawa N, Bergström E, Dessent CEH. UV laser photoactivation of hexachloroplatinate bound to individual nucleobases in vacuo as molecular level probes of a model photopharmaceutical. Phys Chem Chem Phys 2016; 18:15143-52. [DOI: 10.1039/c6cp01676f] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
UV excitation of mass-selected hexachloroplatinate–nucleobase clusters provides detailed insight into the photophysics and photochemistry of a model DNA photopharmaceutical.
Collapse
Affiliation(s)
| | - Ananya Sen
- Department of Chemistry
- University of York
- York
- UK
| | | | | | | |
Collapse
|
35
|
Peperstraete Y, Staniforth M, Baker LA, Rodrigues NDN, Cole-Filipiak NC, Quan WD, Stavros VG. Bottom-up excited state dynamics of two cinnamate-based sunscreen filter molecules. Phys Chem Chem Phys 2016; 18:28140-28149. [DOI: 10.1039/c6cp05205c] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We have used time-resolved pump–probe spectroscopy to explore E-MMC's and E-EHMC's excited state dynamics upon UV-B photoexcitation.
Collapse
|
36
|
Altavilla SF, Segarra-Martí J, Nenov A, Conti I, Rivalta I, Garavelli M. Deciphering the photochemical mechanisms describing the UV-induced processes occurring in solvated guanine monophosphate. Front Chem 2015; 3:29. [PMID: 25941671 PMCID: PMC4403598 DOI: 10.3389/fchem.2015.00029] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 03/30/2015] [Indexed: 01/17/2023] Open
Abstract
The photophysics and photochemistry of water-solvated guanine monophosphate (GMP) are here characterized by means of a multireference quantum-chemical/molecular mechanics theoretical approach (CASPT2//CASSCF/AMBER) in order to elucidate the main photo-processes occurring upon UV-light irradiation. The effect of the solvent and of the phosphate group on the energetics and structural features of this system are evaluated for the first time employing high-level ab initio methods and thoroughly compared to those in vacuo previously reported in the literature and to the experimental evidence to assess to which extent they influence the photoinduced mechanisms. Solvated electronic excitation energies of solvated GMP at the Franck-Condon (FC) region show a red shift for the ππ(*) La and Lb states, whereas the energy of the oxygen lone-pair nπ(*) state is blue-shifted. The main photoinduced decay route is promoted through a ring-puckering motion along the bright lowest-lying La state toward a conical intersection (CI) with the ground state, involving a very shallow stationary point along the minimum energy pathway in contrast to the barrierless profile found in gas-phase, the point being placed at the end of the minimum energy path (MEP) thus endorsing its ultrafast deactivation in accordance with time-resolved transient and photoelectron spectroscopy experiments. The role of the nπ(*) state in the solvated system is severely diminished as the crossings with the initially populated La state and also with the Lb state are placed too high energetically to partake prominently in the deactivation photo-process. The proposed mechanism present in solvated and in vacuo DNA/RNA chromophores validates the intrinsic photostability mechanism through CI-mediated non-radiative processes accompanying the bright excited-state population toward the ground state and subsequent relaxation back to the FC region.
Collapse
Affiliation(s)
| | | | - Artur Nenov
- Dipartimento di Chimica “G. Ciamician,” Università di BolognaBologna, Italy
| | - Irene Conti
- Dipartimento di Chimica “G. Ciamician,” Università di BolognaBologna, Italy
| | - Ivan Rivalta
- École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, UMR 5182, Université de LyonLyon, France
| | - Marco Garavelli
- Dipartimento di Chimica “G. Ciamician,” Università di BolognaBologna, Italy
- École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, UMR 5182, Université de LyonLyon, France
| |
Collapse
|
37
|
Baker LA, Horbury MD, Greenough SE, Coulter PM, Karsili TNV, Roberts GM, Orr-Ewing AJ, Ashfold MNR, Stavros VG. Probing the Ultrafast Energy Dissipation Mechanism of the Sunscreen Oxybenzone after UVA Irradiation. J Phys Chem Lett 2015; 6:1363-8. [PMID: 26263136 DOI: 10.1021/acs.jpclett.5b00417] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Oxybenzone is a common constituent of many commercially available sunscreens providing photoprotection from ultraviolet light incident on the skin. Femtosecond transient electronic and vibrational absorption spectroscopies have been used to investigate the nonradiative relaxation pathways of oxybenzone in cyclohexane and methanol after excitation in the UVA region. The present data suggest that the photoprotective properties of oxybenzone can be understood in terms of an initial ultrafast excited state enol → keto tautomerization, followed by efficient internal conversion and subsequent vibrational relaxation to the ground state (enol) tautomer.
Collapse
Affiliation(s)
- Lewis A Baker
- †Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - Michael D Horbury
- †Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - Simon E Greenough
- †Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - Philip M Coulter
- ‡School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | - Tolga N V Karsili
- ‡School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | - Gareth M Roberts
- ‡School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | - Andrew J Orr-Ewing
- ‡School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | - Michael N R Ashfold
- ‡School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, United Kingdom
| | - Vasilios G Stavros
- †Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| |
Collapse
|
38
|
Szabla R, Campos J, Šponer JE, Šponer J, Góra RW, Sutherland JD. Excited-state hydrogen atom abstraction initiates the photochemistry of β-2'-deoxycytidine. Chem Sci 2015; 6:2035-2043. [PMID: 27182431 PMCID: PMC4866440 DOI: 10.1039/c4sc03761h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 01/07/2015] [Indexed: 11/21/2022] Open
Abstract
Understanding the effects of ultraviolet radiation on nucleotides in solution is an important step towards a comprehensive description of the photochemistry of nucleic acids and their constituents. Apart from having implications for mutagenesis and DNA photoprotection mechanisms, the photochemistry of cytidines is a central element in UV-assisted syntheses of pyrimidine nucleotides under prebiotically plausible conditions. In this contribution, we present UV-irradiation experiments of β-2'-deoxycytidine in aqueous solution involving H-D exchange followed by NMR spectroscopic analysis of the photoproducts. We further elucidate the outcome of these experiments by means of high-level quantum chemical calculations. In particular, we show that prolonged UV-irradiation of cytidine may lead to H-C1' hydrogen atom abstraction by the carbonyl oxygen atom of cytosine. This process may enable photoanomerisation and nucleobase loss, two previously unexplained photoreactions observed in pyrimidine nucleotides.
Collapse
Affiliation(s)
- Rafał Szabla
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic.
| | - Jesús Campos
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK; Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK
| | - Judit E Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic. ; CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, CZ-62500 Brno, Czech Republic
| | - Jiřĺ Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 61265, Brno, Czech Republic. ; CEITEC - Central European Institute of Technology, Masaryk University, Campus Bohunice, Kamenice 5, CZ-62500 Brno, Czech Republic
| | - Robert W Góra
- Theoretical Chemistry Group, Institute of Physical and Theoretical Chemistry, Wroclaw University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wroclaw, Poland.
| | - John D Sutherland
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK.
| |
Collapse
|
39
|
Horke DA, Chatterley AS, Bull JN, Verlet JRR. Time-Resolved Photodetachment Anisotropy: Gas-Phase Rotational and Vibrational Dynamics of the Fluorescein Anion. J Phys Chem Lett 2015; 6:189-94. [PMID: 26263111 DOI: 10.1021/jz5022526] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The photoelectron signal of the singly deprotonated fluorescein anion is found to be highly dependent on the relative polarization between pump and probe pulses, and time-resolved photodetachment anisotropy (TR-PA) is developed as a probe of the rotational dynamics of the chromophore. The total photoelectron signal shows both rotational and vibrational wavepacket dynamics, and we demonstrate how TR-PA can readily disentangle these dynamical processes. TR-PA in fluorescein presents specific opportunities for its development as a probe for rotational dynamics in large biomolecules as fluorescein derivatives are commonly incorporated in complex biomolecules and have been used extensively in time-resolved fluorescence anisotropy measurements, to which TR-PA is a gas-phase analogue.
Collapse
Affiliation(s)
- Daniel A Horke
- †Center for Free-Electron Laser Science, DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Adam S Chatterley
- ‡Ultrafast X-ray Science Laboratory, Cyclotron Road, Berkeley, California 94720, United States
| | - James N Bull
- §Department of Chemistry, University of Durham, South Road, Durham DH1 3LE, United Kingdom
| | - Jan R R Verlet
- §Department of Chemistry, University of Durham, South Road, Durham DH1 3LE, United Kingdom
| |
Collapse
|
40
|
Baker LA, Horbury MD, Greenough SE, Ashfold MNR, Stavros VG. Broadband ultrafast photoprotection by oxybenzone across the UVB and UVC spectral regions. Photochem Photobiol Sci 2015; 14:1814-20. [DOI: 10.1039/c5pp00217f] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Recent studies have shed light on the energy dissipation mechanism of oxybenzone, a common ingredient in commercial sunscreens.
Collapse
|
41
|
Buchner F, Heggen B, Ritze HH, Thiel W, Lübcke A. Excited-state dynamics of guanosine in aqueous solution revealed by time-resolved photoelectron spectroscopy: experiment and theory. Phys Chem Chem Phys 2015; 17:31978-87. [DOI: 10.1039/c5cp04394h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Time-resolved photoelectron spectroscopy is performed on aqueous guanosine solution to study its excited-state relaxation dynamics.
Collapse
Affiliation(s)
- Franziska Buchner
- Max-Born-Institut für nichtlineare Optik und Kurzzeitspektroskopie
- 12489 Berlin
- Germany
| | - Berit Heggen
- Max-Planck-Institut für Kohlenforschung
- 45470 Mülheim/Ruhr
- Germany
| | - Hans-Hermann Ritze
- Max-Born-Institut für nichtlineare Optik und Kurzzeitspektroskopie
- 12489 Berlin
- Germany
| | - Walter Thiel
- Max-Planck-Institut für Kohlenforschung
- 45470 Mülheim/Ruhr
- Germany
| | - Andrea Lübcke
- Max-Born-Institut für nichtlineare Optik und Kurzzeitspektroskopie
- 12489 Berlin
- Germany
| |
Collapse
|