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Professor Jan Verlet's Outputs (116)

The valence electron affinity of uracil determined by anion cluster photoelectron spectroscopy (2024)
Journal Article
Clarke, C. J., Burrow, E. M., & Verlet, J. R. R. (2024). The valence electron affinity of uracil determined by anion cluster photoelectron spectroscopy . Physical Chemistry Chemical Physics, 26(29), 20037-20045. https://doi.org/10.1039/d4cp02146k

The unoccupied π* orbitals of the nucleobases are considered to play important roles in low-energy electron attachment to DNA, inducing damage. While the lowest anionic valence state is vertically unbound in all neutral nucleobases, it remains unclea... Read More about The valence electron affinity of uracil determined by anion cluster photoelectron spectroscopy .

Effect of N Atom Substitution on Electronic Resonances: A 2D Photoelectron Spectroscopic and Computational Study of Anthracene, Acridine, and Phenazine Anions (2024)
Journal Article
Slimak, S., Lietard, A., Jordan, K. D., & Verlet, J. R. R. (2024). Effect of N Atom Substitution on Electronic Resonances: A 2D Photoelectron Spectroscopic and Computational Study of Anthracene, Acridine, and Phenazine Anions. The Journal of Physical Chemistry A, 128(27), 5321-5330. https://doi.org/10.1021/acs.jpca.4c02756

The accommodation of an excess electron by polycyclic aromatic hydrocarbons (PAHs) has important chemical and technological implications ranging from molecular electronics to charge balance in interstellar molecular clouds. Here, we use two-dimension... Read More about Effect of N Atom Substitution on Electronic Resonances: A 2D Photoelectron Spectroscopic and Computational Study of Anthracene, Acridine, and Phenazine Anions.

Photoelectron spectroscopy of the deprotonated tryptophan anion: the contribution of deprotomers to its photodetachment channels (2024)
Journal Article
Gibbard, J. A., Kellow, C. S., & Verlet, J. R. R. (2024). Photoelectron spectroscopy of the deprotonated tryptophan anion: the contribution of deprotomers to its photodetachment channels. Physical Chemistry Chemical Physics, 26(15), 12053-12059. https://doi.org/10.1039/d4cp00309h

Photoelectron spectroscopy and electronic structure calculations are used to investigate the electronic structure of the deprotonated anionic form of the aromatic amino acid tryptophan, and its chromophore, indole. The photoelectron spectra of trypto... Read More about Photoelectron spectroscopy of the deprotonated tryptophan anion: the contribution of deprotomers to its photodetachment channels.

Spectroscopy and dynamics of the hydrated electron at the water/air interface (2024)
Journal Article
Jordan, C. J. C., Coons, M. P., Herbert, J. M., & Verlet, J. R. R. (2024). Spectroscopy and dynamics of the hydrated electron at the water/air interface. Nature Communications, 15(1), Article 182. https://doi.org/10.1038/s41467-023-44441-2

The hydrated electron, e–(aq), has attracted much attention as a central species in radiation chemistry. However, much less is known about e–(aq) at the water/air surface, despite its fundamental role in electron transfer processes at interfaces. Usi... Read More about Spectroscopy and dynamics of the hydrated electron at the water/air interface.

Photodissociation of permanganate (MnO 4 − ) produces the manganese dioxide anion (MnO 2 − ) in an excited triplet state (2023)
Journal Article
Gibbard, J. A., Reppel, J., & Verlet, J. R. R. (2023). Photodissociation of permanganate (MnO 4 − ) produces the manganese dioxide anion (MnO 2 − ) in an excited triplet state. Physical Chemistry Chemical Physics, 25(48), 32939-32947. https://doi.org/10.1039/d3cp04576e

Photoelectron imaging, electron action spectroscopy and electronic structure calculations are used to probe the structure and dynamics of MnO4−. Following excitation to the first bright absorption band of MnO4− (11T2), photodetachment, via ground sta... Read More about Photodissociation of permanganate (MnO 4 − ) produces the manganese dioxide anion (MnO 2 − ) in an excited triplet state.

Electron impact resonances of uracil in an aqueous environment from anion photoelectron imaging (2023)
Journal Article
Cooper, G. A., Clarke, C. J., & Verlet, J. R. R. (2023). Electron impact resonances of uracil in an aqueous environment from anion photoelectron imaging. Journal of Physics B: Atomic, Molecular and Optical Physics, 56(18), Article 185102. https://doi.org/10.1088/1361-6455/acf353

The effect that solvation has on electron attachment to uracil, U, was studied by probing the electronic resonances of the uracil radical anion, U−, in gas-phase water clusters, U−(H2O)n, using photoelectron imaging across a range of photon energies.... Read More about Electron impact resonances of uracil in an aqueous environment from anion photoelectron imaging.

Unraveling the decarboxylation dynamics of the fluorescein dianion with fragment action spectroscopy (2023)
Journal Article
Gibbard, J., & Verlet, J. (2023). Unraveling the decarboxylation dynamics of the fluorescein dianion with fragment action spectroscopy. The Journal of Chemical Physics, 158(15), Article 154306. https://doi.org/10.1063/5.0144851

The decarboxylation dynamics of the doubly deprotonated fluorescein dianion, Fl2−, are investigated by recording fragment action spectra for the anion, Fl−, and its decarboxylated analog, Fl–CO2−, using a new reflectron secondary mass spectrometer. T... Read More about Unraveling the decarboxylation dynamics of the fluorescein dianion with fragment action spectroscopy.

Low-Energy Shape Resonances of a Nucleobase in Water (2022)
Journal Article
Cooper, G. A., Clarke, C. J., & Verlet, J. R. (2022). Low-Energy Shape Resonances of a Nucleobase in Water. Journal of the American Chemical Society, 145(2), 1319-1326. https://doi.org/10.1021/jacs.2c11440

When high-energy radiation passes through aqueous material, low-energy electrons are produced which cause DNA damage. Electronic states of anionic nucleobases have been suggested as an entrance channel to capture the electron. However, identifying th... Read More about Low-Energy Shape Resonances of a Nucleobase in Water.

Allophycocyanin A is a carbon dioxide receptor in the cyanobacterial phycobilisome (2022)
Journal Article
Guillen-Garcia, A., Gibson, S., Jordan, C., Ramaswamy, V., Linthwaite, V., Bromley, E., …Cann, M. (2022). Allophycocyanin A is a carbon dioxide receptor in the cyanobacterial phycobilisome. Nature Communications, 13, Article 5289. https://doi.org/10.1038/s41467-022-32925-6

Light harvesting is fundamental for production of ATP and reducing equivalents for CO2 fixation during photosynthesis. However, electronic energy transfer (EET) through a photosystem can harm the photosynthetic apparatus when not balanced with CO2. H... Read More about Allophycocyanin A is a carbon dioxide receptor in the cyanobacterial phycobilisome.

Kasha’s Rule and Koopmans’ Correlations for Electron Tunnelling through Repulsive Coulomb Barriers in a Polyanion (2022)
Journal Article
Gibbard, J. A., & Verlet, J. R. (2022). Kasha’s Rule and Koopmans’ Correlations for Electron Tunnelling through Repulsive Coulomb Barriers in a Polyanion. Journal of Physical Chemistry Letters, 13(33), 7797-7801. https://doi.org/10.1021/acs.jpclett.2c02145

The long-range electronic structure of polyanions is defined by the repulsive Coulomb barrier (RCB). Excited states can decay by resonant electron tunnelling through RCBs, but such decay has not been observed for electronically excited states other t... Read More about Kasha’s Rule and Koopmans’ Correlations for Electron Tunnelling through Repulsive Coulomb Barriers in a Polyanion.

Resonances in nitrobenzene probed by the electron attachment to neutral and by the photodetachment from anion (2022)
Journal Article
Ranković, M., Nag, P., Anstöter, C. S., Mensa-Bonsu, G., Kumar T.P., R., Verlet, J. R., & Fedor, J. (2022). Resonances in nitrobenzene probed by the electron attachment to neutral and by the photodetachment from anion. The Journal of Chemical Physics, 157(6), Article 064302. https://doi.org/10.1063/5.0101358

We probe resonances (transient anions) in nitrobenzene with the focus on the electron emission from these. Experimentally, we populate resonances in two ways: either by the impact of free electrons on the neutral molecule or by the photoexcitation of... Read More about Resonances in nitrobenzene probed by the electron attachment to neutral and by the photodetachment from anion.

Photooxidation of the Phenolate Anion is Accelerated at the Water/Air Interface (2022)
Journal Article
Jordan, C. J., Lowe, E. A., & Verlet, J. R. (2022). Photooxidation of the Phenolate Anion is Accelerated at the Water/Air Interface. Journal of the American Chemical Society, 144(31), 14012-14015. https://doi.org/10.1021/jacs.2c04935

Molecular photodynamics can be dramatically affected at the water/air interface. Probing such dynamics is challenging, with product formation often probed indirectly through its interaction with interfacial water molecules using time-resolved and pha... Read More about Photooxidation of the Phenolate Anion is Accelerated at the Water/Air Interface.

Photoelectron Imaging Study of the Diplatinum Iodide Dianions [Pt2I6]2– and [Pt2I8]2– (2022)
Journal Article
Gibbard, J. A., & Verlet, J. R. (2022). Photoelectron Imaging Study of the Diplatinum Iodide Dianions [Pt2I6]2– and [Pt2I8]2–. The Journal of Physical Chemistry A, 126(22), https://doi.org/10.1021/acs.jpca.2c02008

Photoelectron spectroscopy has been used to study the electronic structure, photodetachment, and photodissociation of the stable diplatinum iodide dianions [Pt2I6]2– and [Pt2I8]2–. Photoelectron spectra over a range of photon energies show the charac... Read More about Photoelectron Imaging Study of the Diplatinum Iodide Dianions [Pt2I6]2– and [Pt2I8]2–.

Effect of Microhydration on the Temporary Anion States of Pyrene (2022)
Journal Article
Lietard, A., & Verlet, J. R. (2022). Effect of Microhydration on the Temporary Anion States of Pyrene. Journal of Physical Chemistry Letters, 13(16), 3529-3533. https://doi.org/10.1021/acs.jpclett.2c00523

The influence of incremental hydration (≤4) on the electronic resonances of the pyrene anion is studied using two-dimensional photoelectron spectroscopy. The photoexcitation energies of the resonances do not change; therefore, from the anion’s perspe... Read More about Effect of Microhydration on the Temporary Anion States of Pyrene.

Photoelectron imaging of PtI2− and its PtI− photodissociation product (2022)
Journal Article
Gibbard, J. A., & Verlet, J. R. (2022). Photoelectron imaging of PtI2− and its PtI− photodissociation product. The Journal of Chemical Physics, 156(13), https://doi.org/10.1063/5.0085610

The photoelectron imaging of PtI2− is presented over photon energies ranging from hν = 3.2 to 4.5 eV. The electron affinity of PtI2 is found to be 3.4 ± 0.1 eV, and the photoelectron spectrum contains three distinct peaks corresponding to three low-l... Read More about Photoelectron imaging of PtI2− and its PtI− photodissociation product.

Photochemistry of the pyruvate anion produces CO2, CO, CH3–, CH3, and a low energy electron (2022)
Journal Article
Clarke, C. J., Gibbard, J. A., Hutton, L., Verlet, J. R., & Curchod, B. F. (2022). Photochemistry of the pyruvate anion produces CO2, CO, CH3–, CH3, and a low energy electron. Nature Communications, 13(1), Article 937. https://doi.org/10.1038/s41467-022-28582-4

The photochemistry of pyruvic acid has attracted much scientific interest because it is believed to play critical roles in atmospheric chemistry. However, under most atmospherically relevant conditions, pyruvic acid deprotonates to form its conjugate... Read More about Photochemistry of the pyruvate anion produces CO2, CO, CH3–, CH3, and a low energy electron.

A Hückel Model for the Excited-State Dynamics of a Protein Chromophore Developed Using Photoelectron Imaging (2022)
Journal Article
Anstöter, C. S., & Verlet, J. R. (2022). A Hückel Model for the Excited-State Dynamics of a Protein Chromophore Developed Using Photoelectron Imaging. Accounts of Chemical Research, 55(9), 1205-1213. https://doi.org/10.1021/acs.accounts.1c00780

Chemistry can be described as the movement of nuclei within molecules and the concomitant instantaneous change in electronic structure. This idea underpins the central chemical concepts of potential energy surfaces and reaction coordinates. To experi... Read More about A Hückel Model for the Excited-State Dynamics of a Protein Chromophore Developed Using Photoelectron Imaging.

Photo-isomerization of the isolated photoactive yellow protein chromophore: what comes before the primary step? (2021)
Journal Article
Anstöter, C. S., Curchod, B. F., & Verlet, J. R. (2022). Photo-isomerization of the isolated photoactive yellow protein chromophore: what comes before the primary step?. Physical Chemistry Chemical Physics, 24(3), 1305-1309. https://doi.org/10.1039/d1cp05259d

Photoactive proteins typically rely on structural changes in a small chromophore to initiate a biological response. While these changes often involve isomerization as the “primary step”, preceding this is an ultrafast relaxation of the molecular fram... Read More about Photo-isomerization of the isolated photoactive yellow protein chromophore: what comes before the primary step?.

Nonadiabatic Dynamics between Valence, Nonvalence, and Continuum Electronic States in a Heteropolycyclic Aromatic Hydrocarbon (2021)
Journal Article
Bull, J. N., Anstöter, C. S., Stockett, M. H., Clarke, C. J., Gibbard, J. A., Bieske, E. J., & Verlet, J. R. (2021). Nonadiabatic Dynamics between Valence, Nonvalence, and Continuum Electronic States in a Heteropolycyclic Aromatic Hydrocarbon. Journal of Physical Chemistry Letters, 12(49), 11811-11816. https://doi.org/10.1021/acs.jpclett.1c03532

Internal conversion between valence-localized and dipole-bound states is thought to be a ubiquitous process in polar molecular anions, yet there is limited direct evidence. Here, photodetachment action spectroscopy and time-resolved photoelectron ima... Read More about Nonadiabatic Dynamics between Valence, Nonvalence, and Continuum Electronic States in a Heteropolycyclic Aromatic Hydrocarbon.

A Combined Spectrophotometer and Fluorometer to Demonstrate the Principles of Absorption Spectroscopy (2021)
Journal Article
Lietard, A., Screen, M. A., Flindt, D. L., Jordan, C. J., Robson, J. M., & Verlet, J. R. (2021). A Combined Spectrophotometer and Fluorometer to Demonstrate the Principles of Absorption Spectroscopy. Journal of Chemical Education, 98(12), 3871-3877. https://doi.org/10.1021/acs.jchemed.1c00742

A dual-function student-crafted instrument is described as part of a laboratory activity aimed to teach both the principles and practical aspects of absorption spectroscopy to secondary and introductory undergraduate students. Using minimal changes i... Read More about A Combined Spectrophotometer and Fluorometer to Demonstrate the Principles of Absorption Spectroscopy.

Time-resolved electronic sum-frequency generation spectroscopy with fluorescence suppression using optical Kerr gating (2021)
Journal Article
Jordan, C. J., & Verlet, J. R. (2021). Time-resolved electronic sum-frequency generation spectroscopy with fluorescence suppression using optical Kerr gating. The Journal of Chemical Physics, 155(16), https://doi.org/10.1063/5.0065460

Excited state dynamics of molecules at interfaces can be studied using second-order non-linear spectroscopic methods such as time-resolved electronic sum-frequency generation (SFG). However, as such measurements inherently generate very small signals... Read More about Time-resolved electronic sum-frequency generation spectroscopy with fluorescence suppression using optical Kerr gating.

Photoelectron spectroscopy of the protoporphyrin IX dianion (2021)
Journal Article
Gibbard, J. A., Clarke, C. J., & Verlet, J. R. (2021). Photoelectron spectroscopy of the protoporphyrin IX dianion. Physical Chemistry Chemical Physics, 23(34), https://doi.org/10.1039/d1cp03075b

Two-dimensional photoelectron spectroscopy using nanosecond and femtosecond lasers has been used to study the protopophyrin IX dianion at photon energies between 1.8–4.1 eV. The photoelectron spectra indicated the presence of two direct detachment ch... Read More about Photoelectron spectroscopy of the protoporphyrin IX dianion.

Temporary Anion Resonances of Pyrene: A 2D Photoelectron Imaging and Computational Study (2021)
Journal Article
Lietard, A., Verlet, J. R., Slimak, S., & Jordan, K. D. (2021). Temporary Anion Resonances of Pyrene: A 2D Photoelectron Imaging and Computational Study. The Journal of Physical Chemistry A, 125(32), 7004-7013. https://doi.org/10.1021/acs.jpca.1c05586

The low-energy electron-scattering resonances of pyrene were characterized using experimental and computational methods. Experimentally, a two-dimensional photoelectron imaging of the pyrene anion was used to probe the dynamics of resonances over the... Read More about Temporary Anion Resonances of Pyrene: A 2D Photoelectron Imaging and Computational Study.

Modeling the Photoelectron Angular Distributions of Molecular Anions: Roles of the Basis Set, Orbital Choice, and Geometry (2021)
Journal Article
Anstöter, C. S., & Verlet, J. R. (2021). Modeling the Photoelectron Angular Distributions of Molecular Anions: Roles of the Basis Set, Orbital Choice, and Geometry. The Journal of Physical Chemistry A, 125(22), 4888-4895. https://doi.org/10.1021/acs.jpca.1c03379

A study investigating the effect of the basis set, orbital choice, and geometry on the modeling of photoelectron angular distributions (PADs) of molecular anions is presented. Experimental and modeled PADs for a number of molecular anions, including... Read More about Modeling the Photoelectron Angular Distributions of Molecular Anions: Roles of the Basis Set, Orbital Choice, and Geometry.

Intramolecular Photo-Oxidation as a Potential Source to Probe Biological Electron Damage: A Carboxylated Adenosine Analogue as Case Study (2021)
Journal Article
Castellani, M. E., & Verlet, J. R. (2021). Intramolecular Photo-Oxidation as a Potential Source to Probe Biological Electron Damage: A Carboxylated Adenosine Analogue as Case Study. Molecules, 26(10), Article 2877. https://doi.org/10.3390/molecules26102877

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 transfe... Read More about Intramolecular Photo-Oxidation as a Potential Source to Probe Biological Electron Damage: A Carboxylated Adenosine Analogue as Case Study.

The effect of solvation on electron capture revealed using anion two-dimensional photoelectron spectroscopy (2021)
Journal Article
Lietard, A., Mensa-Bonsu, G., & Verlet, J. R. (2021). The effect of solvation on electron capture revealed using anion two-dimensional photoelectron spectroscopy. Nature Chemistry, 13(8), 737-742. https://doi.org/10.1038/s41557-021-00687-1

The reaction of low-energy electrons with neutral molecules to form anions plays an important role in chemistry, being involved in, for example, various biological and astrochemical processes. However, key aspects of electron–molecule interactions, s... Read More about The effect of solvation on electron capture revealed using anion two-dimensional photoelectron spectroscopy.

Ultrafast Dynamics of the Isolated Adenosine-5′-triphosphate Dianion Probed by Time-Resolved Photoelectron Imaging (2021)
Journal Article
Castellani, M. E., Avagliano, D., & Verlet, J. R. (2021). Ultrafast Dynamics of the Isolated Adenosine-5′-triphosphate Dianion Probed by Time-Resolved Photoelectron Imaging. The Journal of Physical Chemistry A, 125(17), 3646-3652. https://doi.org/10.1021/acs.jpca.1c01646

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 spect... Read More about Ultrafast Dynamics of the Isolated Adenosine-5′-triphosphate Dianion Probed by Time-Resolved Photoelectron Imaging.

Autodetachment dynamics of 2-naphthoxide and implications for astrophysical anion abundance (2021)
Journal Article
Ashworth, E. K., Anstöter, C. S., Verlet, J. R., & Bull, J. N. (2021). Autodetachment dynamics of 2-naphthoxide and implications for astrophysical anion abundance. Physical Chemistry Chemical Physics, 23(10), 5817-5823. https://doi.org/10.1039/d1cp00261a

Astrochemical modelling has proposed that 10% or more of interstellar carbon could be tied up as polycyclic aromatic hydrocarbon (PAH) molecules. Developing reliable models of the interstellar carbon lifecycle requires calibration data obtained throu... Read More about Autodetachment dynamics of 2-naphthoxide and implications for astrophysical anion abundance.

Photoelectron imaging of the SO3 anion: vibrational resolution in photoelectron angular distributions* (2020)
Journal Article
Anstöter, C. S., & Verlet, J. R. (2021). Photoelectron imaging of the SO3 anion: vibrational resolution in photoelectron angular distributions*. Molecular Physics, 119(1-2), Article e1821921. https://doi.org/10.1080/00268976.2020.1821921

The photoelectron imaging of the pyramidal sulphite radical monoanion is presented in the photon energy range spanning 3.10–4.45 eV. Two features are seen corresponding to formation of the ground electronic state of the neutral and to thermionic emis... Read More about Photoelectron imaging of the SO3 anion: vibrational resolution in photoelectron angular distributions*.

Site-Specific Photo-oxidation of the Isolated Adenosine-5′-triphosphate Dianion Determined by Photoelectron Imaging (2020)
Journal Article
Castellani, M. E., Avagliano, D., González, L., & Verlet, J. R. (2020). Site-Specific Photo-oxidation of the Isolated Adenosine-5′-triphosphate Dianion Determined by Photoelectron Imaging. Journal of Physical Chemistry Letters, 11(19), 8195-8201. https://doi.org/10.1021/acs.jpclett.0c02089

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... Read More about Site-Specific Photo-oxidation of the Isolated Adenosine-5′-triphosphate Dianion Determined by Photoelectron Imaging.

Gas-phase Synthesis and Characterisation of the Methyl-2,2-dicyanoacetate Anion Using Photoelectron Imaging and Dipole-bound State Autodetachment (2020)
Journal Article
Anstöter, C. S., & Verlet, J. R. (2020). Gas-phase Synthesis and Characterisation of the Methyl-2,2-dicyanoacetate Anion Using Photoelectron Imaging and Dipole-bound State Autodetachment. Journal of Physical Chemistry Letters, 11(15), 6456-6462. https://doi.org/10.1021/acs.jpclett.0c02036

The methyl-2,2-dicyanoacetate anion is synthesised in an electrospray ionisation source through a gas-phase reaction involving tetracyanoethylene and methanol. Photoelectron imaging is used to determine the isomeric form of the product. The photoelec... Read More about Gas-phase Synthesis and Characterisation of the Methyl-2,2-dicyanoacetate Anion Using Photoelectron Imaging and Dipole-bound State Autodetachment.

Geometric and electronic structure probed along the isomerisation coordinate of a photoactive yellow protein chromophore (2020)
Journal Article
Anstöter, C. S., Curchod, B. F., & Verlet, J. R. (2020). Geometric and electronic structure probed along the isomerisation coordinate of a photoactive yellow protein chromophore. Nature Communications, 11(1), Article 2827. https://doi.org/10.1038/s41467-020-16667-x

Understanding the connection between the motion of the nuclei in a molecule and the rearrangement of its electrons lies at the heart of chemistry. While many experimental methods have been developed to probe either the electronic or the nuclear struc... Read More about Geometric and electronic structure probed along the isomerisation coordinate of a photoactive yellow protein chromophore.

Mode-Specific Vibrational Autodetachment Following Excitation of Electronic Resonances by Electrons and Photons (2020)
Journal Article
Anstöter, C. S., Mensa-Bonsu, G., Nag, P., Ranković, M., Kumar T. P., R., Boichenko, A. N., …Verlet, J. R. (2020). Mode-Specific Vibrational Autodetachment Following Excitation of Electronic Resonances by Electrons and Photons. Physical Review Letters, 124(20), Article 203401. https://doi.org/10.1103/physrevlett.124.203401

Electronic resonances commonly decay via internal conversion to vibrationally hot anions and subsequent statistical electron emission. We observed vibrational structure in such an emission from the nitrobenzene anion, in both the 2D electron energy l... Read More about Mode-Specific Vibrational Autodetachment Following Excitation of Electronic Resonances by Electrons and Photons.

Low energy electron impact resonances of anthracene probed by 2D photoelectron imaging of its radical anion (2020)
Journal Article
Mensa-Bonsu, G., Lietard, A., Tozer, D. J., & Verlet, J. R. (2020). Low energy electron impact resonances of anthracene probed by 2D photoelectron imaging of its radical anion. The Journal of Chemical Physics, 152(17), Article 174303. https://doi.org/10.1063/5.0007470

Electron-molecule resonances of anthracene were probed by 2D photoelectron imaging of the corresponding radical anion up to 3.7 eV in the continuum. A number of resonances were observed in both the photoelectron spectra and angular distributions, and... Read More about Low energy electron impact resonances of anthracene probed by 2D photoelectron imaging of its radical anion.

Spectroscopic characterisation of radical polyinterhalogen molecules (2020)
Journal Article
Gregory, J., Verlet, J. R., & Bull, J. N. (2020). Spectroscopic characterisation of radical polyinterhalogen molecules. Physical Chemistry Chemical Physics, 22(16), 8284-8288. https://doi.org/10.1039/d0cp01311k

Spectroscopic characterisations of the radical polyinterhalogen molecules IF2 and I2F are reported using anion photoelectron spectroscopy. The corresponding parent anions, IF2− and I2F−, are common products formed in hard Ar–CF3I plasmas and are rele... Read More about Spectroscopic characterisation of radical polyinterhalogen molecules.

Role of Nonvalence States in the Ultrafast Dynamics of Isolated Anions (2020)
Journal Article
Verlet, J. R., Anstöter, C. S., Bull, J. N., & Rogers, J. P. (2020). Role of Nonvalence States in the Ultrafast Dynamics of Isolated Anions. The Journal of Physical Chemistry A, 124(18), 3507-3519. https://doi.org/10.1021/acs.jpca.0c01260

Nonvalence states of neutral molecules (Rydberg states) play important roles in nonadiabatic dynamics of excited states. In anions, such nonadiabatic transitions between nonvalence and valence states have been much less explored even though they are... Read More about Role of Nonvalence States in the Ultrafast Dynamics of Isolated Anions.

Fingerprinting the Excited State Dynamics in Methyl Ester and Methyl Ether Anions of Deprotonated para-Coumaric Acid (2020)
Journal Article
Bull, J. N., Anstöter, C. S., & Verlet, J. R. (2020). Fingerprinting the Excited State Dynamics in Methyl Ester and Methyl Ether Anions of Deprotonated para-Coumaric Acid. The Journal of Physical Chemistry A, 124(11), 2140-2151. https://doi.org/10.1021/acs.jpca.9b11993

Chromophores based on the para-hydroxycinnamate moiety are widespread in the natural world, including as the photoswitching unit in photoactive yellow protein and as a sunscreen in the leaves of plants. Here, photodetachment action spectroscopy combi... Read More about Fingerprinting the Excited State Dynamics in Methyl Ester and Methyl Ether Anions of Deprotonated para-Coumaric Acid.

Probing the Microsolvation Environment of the Green Fluorescent Protein Chromophore In Vacuo (2020)
Journal Article
Zagorec-Marks, W., Foreman, M. M., Verlet, J. R., & Weber, J. M. (2020). Probing the Microsolvation Environment of the Green Fluorescent Protein Chromophore In Vacuo. Journal of Physical Chemistry Letters, 11(5), 1940-1946. https://doi.org/10.1021/acs.jpclett.0c00105

We present vibrational and electronic photodissociation spectra of a model chromophore of the green fluorescent protein in complexes with up to two water molecules, prepared in a cryogenic ion trap at 160–180 K. We find the band origin of the singly... Read More about Probing the Microsolvation Environment of the Green Fluorescent Protein Chromophore In Vacuo.

Ultrafast valence to non-valence excited state dynamics in a common anionic chromophore (2019)
Journal Article
Bull, J. N., Anstöter, C. S., & Verlet, J. R. (2019). Ultrafast valence to non-valence excited state dynamics in a common anionic chromophore. Nature Communications, 10(1), Article 5820. https://doi.org/10.1038/s41467-019-13819-6

Non-valence states in neutral molecules (Rydberg states) have well-established roles and importance in photochemistry, however, considerably less is known about the role of non-valence states in photo-induced processes in anions. Here, femtosecond ti... Read More about Ultrafast valence to non-valence excited state dynamics in a common anionic chromophore.

Photoelectron spectroscopy of para-benzoquinone cluster anions (2019)
Journal Article
Mensa-Bonsu, G., Wilson, M. R., Tozer, D. J., & Verlet, J. R. (2019). Photoelectron spectroscopy of para-benzoquinone cluster anions. The Journal of Chemical Physics, 151(20), Article 204302. https://doi.org/10.1063/1.5132391

The photoelectron spectra of para-benzoquinone radical cluster anions, (pBQ)n− (n = 2–4), taken at hv = 4.00 eV are presented and compared with the photoelectron spectrum of the monomer (n = 1). For all clusters, a direct detachment peak can be ident... Read More about Photoelectron spectroscopy of para-benzoquinone cluster anions.

Cryogenic Ion Spectroscopy of the Green Fluorescent Protein Chromophore in Vacuo (2019)
Journal Article
Zagorec-Marks, W., Foreman, M. M., Verlet, J. R., & Weber, J. M. (2019). Cryogenic Ion Spectroscopy of the Green Fluorescent Protein Chromophore in Vacuo. Journal of Physical Chemistry Letters, 10(24), 7817-7822. https://doi.org/10.1021/acs.jpclett.9b02916

We present the spectrum of the S1 ← S0 transition of an anionic model for the chromophore of the green fluorescent protein in vacuo at cryogenic temperatures, showing previously unresolved vibrational features, and resolving the band origin at 20850... Read More about Cryogenic Ion Spectroscopy of the Green Fluorescent Protein Chromophore in Vacuo.

Spectroscopic Determination of an Anion-π Bond Strength (2019)
Journal Article
Anstöter, C. S., Rogers, J. P., & Verlet, J. R. (2019). Spectroscopic Determination of an Anion-π Bond Strength. Journal of the American Chemical Society, 141(15), 6132-6135. https://doi.org/10.1021/jacs.9b01345

The anion-π bond has emerged as an important non-valence interaction in supramolecular and biological structure. Although recognized as a strong non-covalent interaction, driven by electrostatic charge-quadrupole moment and correlation interactions,... Read More about Spectroscopic Determination of an Anion-π Bond Strength.

Selectivity in Electron Attachment to Water Clusters (2019)
Journal Article
Lietard, A., & Verlet, J. R. (2019). Selectivity in Electron Attachment to Water Clusters. Journal of Physical Chemistry Letters, 10(6), 1180-1184. https://doi.org/10.1021/acs.jpclett.9b00275

Electron attachment onto water clusters to form water cluster anions is studied by varying the point of electron attachment along a molecular beam axis and probing the produced cluster anions using photoelectron spectroscopy. The results show that th... Read More about Selectivity in Electron Attachment to Water Clusters.

On the Mechanism of Phenolate Photo-Oxidation in Aqueous Solution (2019)
Journal Article
Tyson, A. L., & Verlet, J. R. (2019). On the Mechanism of Phenolate Photo-Oxidation in Aqueous Solution. Journal of Physical Chemistry B (Soft Condensed Matter and Biophysical Chemistry), 123(10), 2373-2379. https://doi.org/10.1021/acs.jpcb.8b11766

The photo-oxidation dynamics following ultraviolet (257 nm) excitation of the phenolate anion in aqueous solution is studied using broadband (550–950 nm) transient absorption spectroscopy. A clear signature from electron ejection is observed on a sub... Read More about On the Mechanism of Phenolate Photo-Oxidation in Aqueous Solution.

Photoelectron Spectroscopy of the Hexafluorobenzene Cluster Anions: (C₆F₆)<sub>n</sub><sup>−</sup> (n = 1 – 5) and I<sup>−</sup>(C₆F₆) (2019)
Journal Article
Rogers, J. P., Anstöter, C. S., Bull, J. N., Curchod, B. F., & Verlet, J. R. (2019). Photoelectron Spectroscopy of the Hexafluorobenzene Cluster Anions: (C₆F₆)n− (n = 1 – 5) and I−(C₆F₆). The Journal of Physical Chemistry A, 123(8), 1602-1612. https://doi.org/10.1021/acs.jpca.8b11627

Frequency-resolved (2D) photoelectron (PE) spectra of the anionic clusters (C6F6)n–, for n = 1–5, and time-resolved PE spectra of I–C6F6 are presented using a newly built instrument and supported by electronic structure calculations. From the 2D PE s... Read More about Photoelectron Spectroscopy of the Hexafluorobenzene Cluster Anions: (C₆F₆)<sub>n</sub><sup>−</sup> (n = 1 – 5) and I<sup>−</sup>(C₆F₆).

Photoelectron spectroscopic study of I−·ICF3: a frontside attack SN2 pre-reaction complex (2018)
Journal Article
Mensa-Bonsu, G., Tozer, D. J., & Verlet, J. R. (2019). Photoelectron spectroscopic study of I−·ICF3: a frontside attack SN2 pre-reaction complex. Physical Chemistry Chemical Physics, 21(26), 13977-13985. https://doi.org/10.1039/c8cp06593d

Photodetachment and 2D photoelectron spectra of the mass-selected I−·CF3I complex are presented together with electronic structure calculations. Calculations show that the I− is located at the iodine side of CF3I. Vertical and adiabatic detachment en... Read More about Photoelectron spectroscopic study of I−·ICF3: a frontside attack SN2 pre-reaction complex.

Time-resolved second harmonic generation with single-shot phase sensitivity (2018)
Journal Article
Tyson, A. L., Woods, D. A., & Verlet, J. R. (2018). Time-resolved second harmonic generation with single-shot phase sensitivity. The Journal of Chemical Physics, 149(20), Article 204201. https://doi.org/10.1063/1.5061817

A time-resolved, phase-sensitive second harmonic generation (SHG) method to probe the excited state dynamics of interfacial species is presented. It is based on an interference measurement between the SHG from a sample and a local oscillator generate... Read More about Time-resolved second harmonic generation with single-shot phase sensitivity.

Electronic structure of the para-dinitrobenzene radical anion: a combined 2D photoelectron imaging and computational study (2018)
Journal Article
Anstöter, C. S., Gartmann, T. E., Stanley, L. H., Bochenkova, A. V., & Verlet, J. R. (2018). Electronic structure of the para-dinitrobenzene radical anion: a combined 2D photoelectron imaging and computational study. Physical Chemistry Chemical Physics, 20(37), 24019-24026. https://doi.org/10.1039/c8cp04877k

The para-dinitrobenzene radical anion has been studied by 2D photoelectron imaging within the energy range of 2.5 eV above the detachment threshold. Supporting electronic structure calculations at the XMCQDPT2 level of the excited states and resonanc... Read More about Electronic structure of the para-dinitrobenzene radical anion: a combined 2D photoelectron imaging and computational study.

Evidence of Electron Capture of an Outgoing Photoelectron Wave by a Nonvalence State in (C6F6)n– (2018)
Journal Article
Rogers, J. P., Anstöter, C. S., & Verlet, J. R. (2018). Evidence of Electron Capture of an Outgoing Photoelectron Wave by a Nonvalence State in (C6F6)n–. Journal of Physical Chemistry Letters, 9, 2504-2509. https://doi.org/10.1021/acs.jpclett.8b00739

Frequency-resolved photoelectron spectra are presented for (C6F6)n– with n = 1–5 that show that C6F6– is solvated by neutral C6F6 molecules. Direct photodetachment channels of C6F6– are observed for all n, leaving the neutral in the S0 ground state o... Read More about Evidence of Electron Capture of an Outgoing Photoelectron Wave by a Nonvalence State in (C6F6)n–.

Ultrafast dynamics of low-energy electron attachment via a non-valence correlation-bound state (2018)
Journal Article
Rogers, J. P., Anstöter, C. S., & Verlet, J. R. (2018). Ultrafast dynamics of low-energy electron attachment via a non-valence correlation-bound state. Nature Chemistry, 10, 341-346. https://doi.org/10.1038/nchem.2912

The primary electron-attachment process in electron-driven chemistry represents one of the most fundamental chemical transformations with wide-ranging importance in science and technology. However, the mechanistic detail of the seemingly simple react... Read More about Ultrafast dynamics of low-energy electron attachment via a non-valence correlation-bound state.

Chromophores of chromophores: a bottom-up Hückel picture of the excited states of photoactive proteins (2017)
Journal Article
Anstöter, C. S., Dean, C. R., & Verlet, J. R. (2017). Chromophores of chromophores: a bottom-up Hückel picture of the excited states of photoactive proteins. Physical Chemistry Chemical Physics, 19(44), 29772-29779. https://doi.org/10.1039/c7cp05766k

Many photoactive proteins contain chromophores based on para-substituted phenolate anions which are an essential component of their electronic structure. Here, we present a reductionist approach to gain fundamental insight into the evolution of elect... Read More about Chromophores of chromophores: a bottom-up Hückel picture of the excited states of photoactive proteins.

Dynamics of π*-resonances in anionic clusters of para-toluquinone (2017)
Journal Article
Bull, J. N., & Verlet, J. R. (2017). Dynamics of π*-resonances in anionic clusters of para-toluquinone. Physical Chemistry Chemical Physics, 19(39), 26589-26595. https://doi.org/10.1039/c7cp03628k

Frequency-resolved photoelectron spectroscopy applied to mass-selected cluster anions is an insightful approach to characterise the dynamics of π*-resonances with microsolvation. Here, the technique is demonstrated with monomer, dimer and trimer radi... Read More about Dynamics of π*-resonances in anionic clusters of para-toluquinone.

Observation and ultrafast dynamics of a nonvalence correlation-bound state of an anion (2017)
Journal Article
Bull, J. N., & Verlet, J. R. (2017). Observation and ultrafast dynamics of a nonvalence correlation-bound state of an anion. Science Advances, 3(5), Article e1603106. https://doi.org/10.1126/sciadv.1603106

Nonvalence states of molecular anions play key roles in processes, such as electron mobility, in rare-gas liquids, radiation-induced damage to DNA, and the formation of anions in the interstellar medium. Recently, a class of nonvalence bound anion st... Read More about Observation and ultrafast dynamics of a nonvalence correlation-bound state of an anion.

Sensitivity of Photoelectron Angular Distributions to Molecular Conformations of Anions (2017)
Journal Article
Anstöter, C. S., Dean, C. R., & Verlet, J. R. (2017). Sensitivity of Photoelectron Angular Distributions to Molecular Conformations of Anions. Journal of Physical Chemistry Letters, 8(10), 2268-2273. https://doi.org/10.1021/acs.jpclett.7b00726

An anion photoelectron imaging study probing the sensitivity of the photoelectron angular distribution (PAD) to conformational changes is presented. The PADs of a series of para-substituted phenolate anions is compared with those calculated using the... Read More about Sensitivity of Photoelectron Angular Distributions to Molecular Conformations of Anions.

Resonances of the anthracenyl anion probed by frequency-resolved photoelectron imaging of collision-induced dissociated anthracene carboxylic acid (2017)
Journal Article
Stanley, L. H., Anstöter, C. S., & Verlet, J. R. (2017). Resonances of the anthracenyl anion probed by frequency-resolved photoelectron imaging of collision-induced dissociated anthracene carboxylic acid. Chemical Science, 8(4), 3054-3061. https://doi.org/10.1039/c6sc05405f

Resonances in polyaromatic hydrocarbon (PAH) anions are key intermediates in a number of processes such as electron transfer in organic electronics and electron attachment in the interstellar medium. Here we present a frequency- and angle-resolved ph... Read More about Resonances of the anthracenyl anion probed by frequency-resolved photoelectron imaging of collision-induced dissociated anthracene carboxylic acid.

Charged Particle Imaging of the Deprotonated Octatrienoic Acid Anion: Evidence for a Photoinduced Cyclization Reaction (2016)
Journal Article
West, C., Bull, J., & Verlet, J. (2016). Charged Particle Imaging of the Deprotonated Octatrienoic Acid Anion: Evidence for a Photoinduced Cyclization Reaction. Journal of Physical Chemistry Letters, 7(22), 4635-4640. https://doi.org/10.1021/acs.jpclett.6b02302

Photoelectron spectroscopy of the deprotonated octatrienoic acid anion, [C7H9–CO2]−, shows the formation of [C7H9]− and loss of H– at hν = 4.13 eV. Using velocity map imaging, the H– fragment was characterized to have a Boltzmann-like kinetic energy... Read More about Charged Particle Imaging of the Deprotonated Octatrienoic Acid Anion: Evidence for a Photoinduced Cyclization Reaction.

Charge Transfer to Solvent Dynamics at the Ambient Water/Air Interface (2016)
Journal Article
Nowakowski, P., Woods, D., & Verlet, J. (2016). Charge Transfer to Solvent Dynamics at the Ambient Water/Air Interface. Journal of Physical Chemistry Letters, 7(20), 4079-4085. https://doi.org/10.1021/acs.jpclett.6b01985

Electron-transfer reactions at ambient aqueous interfaces represent one of the most fundamental and ubiquitous chemical reactions. Here the dynamics of the charge transfer to solvent (CTTS) reaction from iodide was probed at the ambient water/air int... Read More about Charge Transfer to Solvent Dynamics at the Ambient Water/Air Interface.

Plasma–liquid interactions: a review and roadmap (2016)
Journal Article
Bruggeman, P., Kushner, M., Locke, B., Gardeniers, J., Graham, W., Graves, D., …Zvereva, G. (2016). Plasma–liquid interactions: a review and roadmap. Plasma Sources Science and Technology, 25(5), Article 053002. https://doi.org/10.1088/0963-0252/25/5/053002

Plasma–liquid interactions represent a growing interdisciplinary area of research involving plasma science, fluid dynamics, heat and mass transfer, photolysis, multiphase chemistry and aerosol science. This review provides an assessment of the state-... Read More about Plasma–liquid interactions: a review and roadmap.

Ultrafast dynamics of temporary anions probed through the prism of photodetachment (2016)
Journal Article
Anstöter, C., Bull, J., & Verlet, J. (2016). Ultrafast dynamics of temporary anions probed through the prism of photodetachment. International Reviews in Physical Chemistry, 35(4), 509-538. https://doi.org/10.1080/0144235x.2016.1203522

The recently developed method of frequency-, angle-, and time-resolved photoelectron imaging (FAT-PI) applied to the study of the dynamics of resonances of open-shell anions is reviewed. The basic principles of the method and its experimental realisa... Read More about Ultrafast dynamics of temporary anions probed through the prism of photodetachment.

The Vitamin E Radical Probed by Anion Photoelectron Imaging (2016)
Journal Article
Anstöter, C., West, C., Bull, J., & Verlet, J. (2016). The Vitamin E Radical Probed by Anion Photoelectron Imaging. Journal of Physical Chemistry B (Soft Condensed Matter and Biophysical Chemistry), 120(29), 7108-7113. https://doi.org/10.1021/acs.jpcb.6b05271

The biological antioxidant activity of vitamin E has been related to the stability of the tocopheroxyl radical. Using anion photoelectron imaging and electronic structure calculations, the four tocopheroxyl components of vitamin E have been studied i... Read More about The Vitamin E Radical Probed by Anion Photoelectron Imaging.

Ultrafast dynamics of formation and autodetachment of a dipole-bound state in an open-shell π-stacked dimer anion (2016)
Journal Article
Bull, J., West, C., & Verlet, J. (2016). Ultrafast dynamics of formation and autodetachment of a dipole-bound state in an open-shell π-stacked dimer anion. Chemical Science, 7(8), 5352-5361. https://doi.org/10.1039/c6sc01062h

Isolated π-stacked dimer radical anions present the simplest model of an excess electron in a π-stacked environment. Here, frequency-, angle-, and time-resolved photoelectron imaging together with electronic structure calculations have been used to c... Read More about Ultrafast dynamics of formation and autodetachment of a dipole-bound state in an open-shell π-stacked dimer anion.

Gas-Phase Femtosecond Particle Spectroscopy: A Bottom-Up Approach to Nucleotide Dynamics (2016)
Journal Article
Stavros, V., & Verlet, J. (2016). Gas-Phase Femtosecond Particle Spectroscopy: A Bottom-Up Approach to Nucleotide Dynamics. Annual Review of Physical Chemistry, 67(1), 211-232. https://doi.org/10.1146/annurev-physchem-040215-112428

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... Read More about Gas-Phase Femtosecond Particle Spectroscopy: A Bottom-Up Approach to Nucleotide Dynamics.

Photoelectron imaging as a probe of the repulsive Coulomb barrier in the photodetachment of antimony tartrate dianions (2015)
Journal Article
West, C., Bull, J., Woods, D., & Verlet, J. (2016). Photoelectron imaging as a probe of the repulsive Coulomb barrier in the photodetachment of antimony tartrate dianions. Chemical Physics Letters, 645, 138-143. https://doi.org/10.1016/j.cplett.2015.12.041

A photoelectron imaging study of the text-book antimony tartrate dianion is presented. The vertical and adiabatic detachment energies are determined to be 2.5 ± 0.1 eV and 2.1 ± 0.2 eV, respectively. The photoelectron spectra exhibit a typical cut-of... Read More about Photoelectron imaging as a probe of the repulsive Coulomb barrier in the photodetachment of antimony tartrate dianions.

Internal conversion outcompetes autodetachment from resonances in the deprotonated tetracene anion continuum (2015)
Journal Article
Bull, J., West, C., & Verlet, J. (2015). Internal conversion outcompetes autodetachment from resonances in the deprotonated tetracene anion continuum. Physical Chemistry Chemical Physics, 17(48), 32464-32471. https://doi.org/10.1039/c5cp05388a

Photoelectron velocity-map imaging and electronic structure calculations have been used to study the temporary anion (resonance) dynamics of the closed-shell site-specific deprotonated tetracene anion (C18H11−) in the hv = 3.26 eV (380 nm) to 4.13 eV... Read More about Internal conversion outcompetes autodetachment from resonances in the deprotonated tetracene anion continuum.

Anion resonances and above-threshold dynamics of coenzyme Q0 (2015)
Journal Article
Bull, J., West, C., & Verlet, J. (2015). Anion resonances and above-threshold dynamics of coenzyme Q0. Physical Chemistry Chemical Physics, 17(24), 16125-16135. https://doi.org/10.1039/c5cp02145f

Temporary radical anions (resonances) of isolated co enzyme Q0 (CQ0) and their associated above-threshold dynamics have been studied using frequency-, angle-, and time-resolved photoelectron imaging (FAT-PI). Experimental energetics and dynamics are... Read More about Anion resonances and above-threshold dynamics of coenzyme Q0.

Excited State Dynamics of the Isolated Green Fluorescent Protein Chromophore Anion Following UV Excitation (2015)
Journal Article
West, C., Bull, J., Hudson, A., Cobb, S., & Verlet, J. (2015). Excited State Dynamics of the Isolated Green Fluorescent Protein Chromophore Anion Following UV Excitation. Journal of Physical Chemistry B (Soft Condensed Matter and Biophysical Chemistry), 119(10), 3982-3987. https://doi.org/10.1021/acs.jpcb.5b01432

A combined frequency-, angle-, and time-resolved photoelectron spectroscopy study is used to unravel the excited state dynamics following UV excitation of the isolated anionic chromophore of the green fluorescent protein (GFP). The optically bright S... Read More about Excited State Dynamics of the Isolated Green Fluorescent Protein Chromophore Anion Following UV Excitation.

Time-resolved phase-sensitive second harmonic generation spectroscopy (2015)
Journal Article
Nowakowski, P. J., Woods, D. A., Bain, C. D., & Verlet, J. R. (2015). Time-resolved phase-sensitive second harmonic generation spectroscopy. The Journal of Chemical Physics, 142(8), https://doi.org/10.1063/1.4909522

A methodology based on time-resolved, phase-sensitive second harmonic generation (SHG) for probing the excited state dynamics of species at interfaces is presented. It is based on an interference measurement between the SHG from the sample and a loca... Read More about Time-resolved phase-sensitive second harmonic generation spectroscopy.

Time-Resolved Photodetachment Anisotropy: Gas-Phase Rotational and Vibrational Dynamics of the Fluorescein Anion (2015)
Journal Article
Horke, D., Chatterley, A., Bull, J., & Verlet, J. (2015). Time-Resolved Photodetachment Anisotropy: Gas-Phase Rotational and Vibrational Dynamics of the Fluorescein Anion. Journal of Physical Chemistry Letters, 6(1), 189-194. https://doi.org/10.1021/jz5022526

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 rota... Read More about Time-Resolved Photodetachment Anisotropy: Gas-Phase Rotational and Vibrational Dynamics of the Fluorescein Anion.

On the formation of anions: frequency-, angle-, and time-resolved photoelectron imaging of the menadione radical anion (2014)
Journal Article
Bull, J. N., West, C. W., & Verlet, J. R. (2015). On the formation of anions: frequency-, angle-, and time-resolved photoelectron imaging of the menadione radical anion. Chemical Science, 6(2), 1578-1589. https://doi.org/10.1039/c4sc03491k

Frequency-, angle-, and time-resolved photoelectron imaging of gas-phase menadione (vitamin K3) radical anions was used to show that quasi-bound resonances of the anion can act as efficient doorway states to produce metastable ground electronic state... Read More about On the formation of anions: frequency-, angle-, and time-resolved photoelectron imaging of the menadione radical anion.

Anion Resonances of para-Benzoquinone Probed by Frequency-Resolved Photoelectron Imaging (2014)
Journal Article
West, C., Bull, J., Antonkov, E., & Verlet, J. (2014). Anion Resonances of para-Benzoquinone Probed by Frequency-Resolved Photoelectron Imaging. The Journal of Physical Chemistry A, 118(48), 11346-11354. https://doi.org/10.1021/jp509102p

The resonant attachment of a free electron to a closed shell neutral molecule and the interplay between the following electron detachment and electronic relaxation channels represents a fundamental but common process throughout chemical and biochemic... Read More about Anion Resonances of para-Benzoquinone Probed by Frequency-Resolved Photoelectron Imaging.

Time-resolved photoelectron imaging of the isolated deprotonated nucleotides (2014)
Journal Article
Chatterley, A., West, C., Stavros, V., & Verlet, J. (2014). Time-resolved photoelectron imaging of the isolated deprotonated nucleotides. Chemical Science, 5(10), 3963-3975. https://doi.org/10.1039/c4sc01493f

Using time-resolved photoelectron spectroscopy, the excited state dynamics of gas-phase mass-selected nucleotide anions have been monitored following UV excitation at 4.66 eV. The spectra reveal that the dynamics of the 2′-deoxyguanosine 5′-monophosp... Read More about Time-resolved photoelectron imaging of the isolated deprotonated nucleotides.

Excited states of multiply-charged anions probed by photoelectron imaging: riding the repulsive Coulomb barrier (2014)
Journal Article
Verlet, J., Horke, D., & Chatterley, A. (2014). Excited states of multiply-charged anions probed by photoelectron imaging: riding the repulsive Coulomb barrier. Physical Chemistry Chemical Physics, 16(29), 15043-15052. https://doi.org/10.1039/c4cp01667j

Many properties of isolated multiply-charged anions (MCAs) are dictated by the strong intra-molecular Coulomb interactions that are present. The most striking property of MCAs is a long-range repulsive Coulomb barrier (RCB) that arises from the repul... Read More about Excited states of multiply-charged anions probed by photoelectron imaging: riding the repulsive Coulomb barrier.

Mapping the Ultrafast Dynamics of Adenine onto Its Nucleotide and Oligonucleotides by Time-Resolved Photoelectron Imaging (2014)
Journal Article
Chatterley, A., West, C., Roberts, G., Stavros, V., & Verlet, J. (2014). Mapping the Ultrafast Dynamics of Adenine onto Its Nucleotide and Oligonucleotides by Time-Resolved Photoelectron Imaging. Journal of Physical Chemistry Letters, 5(5), 843-848. https://doi.org/10.1021/jz500264c

The intrinsic photophysics of nucleobases and nucleotides following UV absorption presents a key reductionist step toward understanding the complex photodamage mechanisms occurring in DNA. The decay mechanism of adenine in particular has been the foc... Read More about Mapping the Ultrafast Dynamics of Adenine onto Its Nucleotide and Oligonucleotides by Time-Resolved Photoelectron Imaging.

Effects of resonant excitation, pulse duration and intensity on photoelectron imaging of a dianion (2014)
Journal Article
Chatterley, A., Horke, D., & Verlet, J. (2014). Effects of resonant excitation, pulse duration and intensity on photoelectron imaging of a dianion. Physical Chemistry Chemical Physics, 16(2), 489-496. https://doi.org/10.1039/c3cp53235f

The photoelectron imaging of the indigo carmine dianion is used to demonstrate the effects of resonance excitation, pulse duration and pulse intensity on the photoelectron spectra and angular distributions of a dianion. Excitation of the S1 state lea... Read More about Effects of resonant excitation, pulse duration and intensity on photoelectron imaging of a dianion.

Influence of the repulsive Coulomb barrier on photoelectron spectra and angular distributions in a resonantly excited dianion (2013)
Journal Article
Horke, D., Chatterley, A., & Verlet, J. (2013). Influence of the repulsive Coulomb barrier on photoelectron spectra and angular distributions in a resonantly excited dianion. The Journal of Chemical Physics, 139(8), Article 084302. https://doi.org/10.1063/1.4818597

A photoelectron imaging study of the gas-phase dianion of pyrromethene-556 is presented. The photoelectron spectra and angular distributions following resonant excitation of the S1 excited state with nanosecond and femtosecond laser pulses are compar... Read More about Influence of the repulsive Coulomb barrier on photoelectron spectra and angular distributions in a resonantly excited dianion.

Communication: Autodetachment versus internal conversion from the S1 state of the isolated GFP chromophore anion (2013)
Journal Article
West, C., Hudson, A., Cobb, S., & Verlet, J. (2013). Communication: Autodetachment versus internal conversion from the S1 state of the isolated GFP chromophore anion. The Journal of Chemical Physics, 139(7), https://doi.org/10.1063/1.4819078

The anionic form of p-hydroxybenzylidene-2,3-dimethylimidazolinone (HBDI) has been extensively employed as a model of the chromophore of the green fluorescence protein. The bright S1 excited state HBDI− has a measured lifetime of 1.4 ps in the gas-ph... Read More about Communication: Autodetachment versus internal conversion from the S1 state of the isolated GFP chromophore anion.

Ultrafast above-threshold dynamics of the radical anion of a prototypical quinone electron-acceptor (2013)
Journal Article
Horke, D., Li, Q., Blancafort, L., & Verlet, J. (2013). Ultrafast above-threshold dynamics of the radical anion of a prototypical quinone electron-acceptor. Nature Chemistry, 5(8), 711-717. https://doi.org/10.1038/nchem.1705

Quinones feature prominently as electron acceptors in nature. Their electron-transfer reactions are often highly exergonic, for which Marcus theory predicts reduced electron-transfer rates because of a free-energy barrier that occurs in the inverted... Read More about Ultrafast above-threshold dynamics of the radical anion of a prototypical quinone electron-acceptor.

Base-Specific Ionization of Deprotonated Nucleotides by Resonance Enhanced Two-Photon Detachment (2013)
Journal Article
Chatterley, A., Johns, A., Stavros, V., & Verlet, J. (2013). Base-Specific Ionization of Deprotonated Nucleotides by Resonance Enhanced Two-Photon Detachment. The Journal of Physical Chemistry A, 117(25), 5299-5305. https://doi.org/10.1021/jp4041315

The intrinsic ionization energy of a base in DNA plays a critical role in determining the energies at which damage mechanisms may emerge. Here, a two-photon resonance-enhanced ionization scheme is presented that utilizes the 1ππ* transition, localize... Read More about Base-Specific Ionization of Deprotonated Nucleotides by Resonance Enhanced Two-Photon Detachment.

Taking the green fluorescence out of the protein:dynamics of the isolated GFP chromophore anion (2013)
Journal Article
Mooney, C., Horke, D., Chatterley, A., Simperler, A., Fielding, H., & Verlet, J. (2013). Taking the green fluorescence out of the protein:dynamics of the isolated GFP chromophore anion. Chemical Science, 4(3), 921-927. https://doi.org/10.1039/c2sc21737f

The green fluorescent protein (GFP) is employed extensively as a marker in biology and the life sciences as a result of its spectacular fluorescence properties. Here, we employ femtosecond time-resolved photoelectron spectroscopy to investigate the u... Read More about Taking the green fluorescence out of the protein:dynamics of the isolated GFP chromophore anion.

On the intrinsic photophysics of indigo: a time-resolved photoelectron spectroscopy study of the indigo carmine dianion (2012)
Journal Article
Chatterley, A., Horke, D., & Verlet, J. (2012). On the intrinsic photophysics of indigo: a time-resolved photoelectron spectroscopy study of the indigo carmine dianion. Physical Chemistry Chemical Physics, 14(46), 16155-16161. https://doi.org/10.1039/c2cp43275g

The intrinsic photophysics of indigo has been studied using gas-phase time-resolved photoelectron imaging of the indigo carmine dianion (InC2−). The action spectrum reveals that the gas-phase absorption spectrum arising from the S1 ← S0 transition in... Read More about On the intrinsic photophysics of indigo: a time-resolved photoelectron spectroscopy study of the indigo carmine dianion.

Photoelectron spectroscopy of the model GFP chromophore anion (2012)
Journal Article
Horke, D., & Verlet, J. (2012). Photoelectron spectroscopy of the model GFP chromophore anion. Physical Chemistry Chemical Physics, 14(24), 8511-8515. https://doi.org/10.1039/c2cp40880e

A photoelectron spectroscopy study of the anionic model chromophore of the green fluorescent protein is presented. From the photoelectron spectra taken at 3.496 eV, 4.62 eV, and 6.15 eV the vertical and adiabatic detachment energies are determined to... Read More about Photoelectron spectroscopy of the model GFP chromophore anion.

Velocity-map imaging at low extraction fields (2012)
Journal Article
Horke, D., Roberts, G., Lecointre, J., & Verlet, J. (2012). Velocity-map imaging at low extraction fields. Review of Scientific Instruments, 83(6), https://doi.org/10.1063/1.4724311

We present a velocity-map imaging (VMI) setup for photoelectron imaging that utilizes low electric extraction fields. This avoids any complications that could arise from electrostatic interactions between the extraction field and the molecular proper... Read More about Velocity-map imaging at low extraction fields.

Femtosecond Photoelectron Imaging of Aligned Polyanions: Probing Molecular Dynamics through the Electron−Anion Coulomb Repulsion (2012)
Journal Article
Horke, D., Chatterley, A., & Verlet, J. (2012). Femtosecond Photoelectron Imaging of Aligned Polyanions: Probing Molecular Dynamics through the Electron−Anion Coulomb Repulsion. Journal of Physical Chemistry Letters, 3(7), 834-838. https://doi.org/10.1021/jz3000933

The first time-resolved photoelectron imaging study of a polyanion is presented. Using the alignment induced through resonance excitation, the photoelectron angular distributions can be qualitatively understood in terms of the position of localized e... Read More about Femtosecond Photoelectron Imaging of Aligned Polyanions: Probing Molecular Dynamics through the Electron−Anion Coulomb Repulsion.

Effect of Internal Energy on the Repulsive Coulomb Barrier of Polyanions (2012)
Journal Article
Horke, D., Chatterley, A., & Verlet, J. (2012). Effect of Internal Energy on the Repulsive Coulomb Barrier of Polyanions. Physical Review Letters, 108(8), Article 083003. https://doi.org/10.1103/physrevlett.108.083003

The nature of the repulsive Coulomb barrier in isolated molecular polyanions is studied by means of the photodetachment dynamics of the S1 excited state of the fluorescein dianion which is bound solely by the repulsive Coulomb barrier. Photoelectron... Read More about Effect of Internal Energy on the Repulsive Coulomb Barrier of Polyanions.

Time-resolved photoelectron imaging of the chloranil radical anion: ultrafast relaxation of electronically excited electron acceptor states (2011)
Journal Article
Horke, D., & Verlet, J. (2011). Time-resolved photoelectron imaging of the chloranil radical anion: ultrafast relaxation of electronically excited electron acceptor states. Physical Chemistry Chemical Physics, 13(43), 19546-19552. https://doi.org/10.1039/c1cp22237f

The spectroscopy and dynamics of near-threshold excited states of the isolated chloranil radical anion are investigated using photoelectron imaging. The photoelectron images taken at 480 nm clearly indicate resonance-enhanced photodetachment via a bo... Read More about Time-resolved photoelectron imaging of the chloranil radical anion: ultrafast relaxation of electronically excited electron acceptor states.

Excited States in Electron-Transfer Reaction Products: Ultrafast Relaxation Dynamics of an Isolated Acceptor Radical Anion (2011)
Journal Article
Horke, D., Roberts, G., & Verlet, J. (2011). Excited States in Electron-Transfer Reaction Products: Ultrafast Relaxation Dynamics of an Isolated Acceptor Radical Anion. The Journal of Physical Chemistry A, 115(30), 8369-8374. https://doi.org/10.1021/jp2038202

The spectroscopy and ultrafast relaxation dynamics of excited states of the radical anion of a representative charge-transfer acceptor molecule, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, have been studied in the gas phase using time-resol... Read More about Excited States in Electron-Transfer Reaction Products: Ultrafast Relaxation Dynamics of an Isolated Acceptor Radical Anion.

Ultrafast Relaxation Dynamics Observed Through Time-Resolved Photoelectron Angular Distributions (2010)
Journal Article
Lecointre, J., Roberts, G., Horke, D., & Verlet, J. (2010). Ultrafast Relaxation Dynamics Observed Through Time-Resolved Photoelectron Angular Distributions. The Journal of Physical Chemistry A, 114(42), 11216-11224. https://doi.org/10.1021/jp1028855

Time-resolved photoelectron imaging of the 7,7,8,8-tetracyanoquinodimethane (TCNQ) radical anion is presented. Photoelectron angular distributions (PADs) are qualitatively analyzed in terms of the simple s-p model that is based on symmetry arguments.... Read More about Ultrafast Relaxation Dynamics Observed Through Time-Resolved Photoelectron Angular Distributions.

Spectroscopy and dynamics of the 7,7,8,8-tetracyanoquinodimethane radical anion (2010)
Journal Article
Roberts, G., Lecointre, J., Horke, D., & Verlet, J. .. (2010). Spectroscopy and dynamics of the 7,7,8,8-tetracyanoquinodimethane radical anion. Physical Chemistry Chemical Physics, 12(23), 6226-6232. https://doi.org/10.1039/c001438a

The photoelectron spectrum of the 7,7,8,8-tetracyanoquinodimethane (TCNQ) radical anion has been measured at 3.1 eV. Additionally, the ultrafast relaxation dynamics of the first excited state (12B3u) of TCNQ− have been studied using time-resolved pho... Read More about Spectroscopy and dynamics of the 7,7,8,8-tetracyanoquinodimethane radical anion.

Toward real-time charged-particle image reconstruction using polar onion-peeling (2009)
Journal Article
Roberts, G., Nixon, J., Lecointre, J., Wrede, E., & Verlet, J. (2009). Toward real-time charged-particle image reconstruction using polar onion-peeling. Review of Scientific Instruments, 80(5), Article 053104. https://doi.org/10.1063/1.3126527

A method to reconstruct full three-dimensional photofragment distributions from their two-dimensional (2D) projection onto a detection plane is presented, for processes in which the expanding Newton sphere has cylindrical symmetry around an axis para... Read More about Toward real-time charged-particle image reconstruction using polar onion-peeling.

Observation of large water-cluster anions with surface-bound excess electrons (2005)
Journal Article
Verlet, J., Bragg, A., Kammrath, A., Cheshnovsky, O., & Neumark, D. (2005). Observation of large water-cluster anions with surface-bound excess electrons. Science, 307(5706), 93-96. https://doi.org/10.1126/science.1106719

Anionic water clusters have long been studied to infer properties of the bulk hydrated electron. We used photoelectron imaging to characterize a class of (H2O)n– and (D2O)n– cluster anions (n 200 molecules) with vertical binding energies that are sig... Read More about Observation of large water-cluster anions with surface-bound excess electrons.

Hydrated electron dynamics: from clusters to bulk (2004)
Journal Article
Bragg, A., Verlet, J., Kammrath, A., Cheshnovsky, O., & Neumark, D. (2004). Hydrated electron dynamics: from clusters to bulk. Science, 306(5696), 669-671. https://doi.org/10.1126/science.1103527

The electronic relaxation dynamics of size-selected (H2O)n–/(D2O)n[25 n 50] clusters have been studied with time-resolved photoelectron imaging. The excess electron () was excited through the transition with an ultrafast laser pulse, with subsequent... Read More about Hydrated electron dynamics: from clusters to bulk.

Optical control of the rotational angular momentum of a molecular Rydberg wave packet (2003)
Journal Article
Minns, R., Patel, R., Verlet, J., & Fielding, H. (2003). Optical control of the rotational angular momentum of a molecular Rydberg wave packet. Physical Review Letters, 91(24), https://doi.org/10.1103/physrevlett.91.243601

An intuitive scheme for controlling the rotational quantum state of a Rydberg molecule is demonstrated experimentally. We determine the accumulated phase difference between the various components of a molecular electron wave packet, and then employ a... Read More about Optical control of the rotational angular momentum of a molecular Rydberg wave packet.

Controlling the angular momentum composition of a Rydberg electron wave packet (2002)
Journal Article
Verlet, J., Stavros, V., Minns, R., & Fielding, H. (2002). Controlling the angular momentum composition of a Rydberg electron wave packet. Physical Review Letters, 89(26), https://doi.org/10.1103/physrevlett.89.263004

Sequences of phase-locked laser pulses have been employed to control the orbital angular momentum character of an electron wave packet, which is initially created from a superposition of s and d Rydberg series. By an intelligent choice of phase, whic... Read More about Controlling the angular momentum composition of a Rydberg electron wave packet.