1
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Marlton SJP, Liu C, Watkins P, Bieske EJ. Gas-phase electronic spectra of HC 2n+1H + ( n = 2-6) chains. Phys Chem Chem Phys 2024; 26:12306-12315. [PMID: 38623876 DOI: 10.1039/d4cp00625a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Highly unsaturated carbon chains are generated in combustion processes and electrical discharges, and are confirmed constituents of the interstellar medium. In hydrogen-rich environments smaller carbon clusters tend to exist as linear chains, capped on each end by hydrogen atoms. Although the HC2nH+ polyacetylene chains have been extensively characterized spectroscopically, the corresponding odd HC2n+1H+ chains have received far less attention. Here we use two-colour resonance enhanced photodissociation spectroscopy to measure electronic spectra for HC2n+1H+ (n = 2-6) chains contained in a cryogenically cooled quadrupole ion trap. The HC2n+1H+ chains are formed either top-down by ionizing and fragmenting pyrene molecules using pulsed 266 nm radiation, or bottom-up by reacting cyclic carbon cluster cations with acetylene. Ion mobility measurements confirm that the HC2n+1H+ species are linear, consistent with predictions from electronic structure calculations. The HC2n+1H+ electronic spectra exhibit three band systems in the visible/near infrared spectral range, which each shifts progressively to longer wavelength by ≈90 nm with the addition of each additional CC subunit. The strongest visible HC11H+ band has a wavelength (λ = 545.1 nm) and width (1.5 nm) that match the strong λ 5450 diffuse interstellar band (DIB). However, other weaker HC11H+ bands do not correspond to catalogued DIBs, casting doubt on the role of HC11H+ as a carrier for the λ 5450 DIB. There are no identifiable correspondences between catalogued DIBs and bands for the other HC2n+1H+ chains, allowing upper limits to be established for their column densities in diffuse interstellar clouds.
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Affiliation(s)
- Samuel J P Marlton
- School of Chemistry, University of Melbourne, Parkville 3010, Australia.
| | - Chang Liu
- School of Chemistry, University of Melbourne, Parkville 3010, Australia.
| | - Patrick Watkins
- School of Chemistry, University of Melbourne, Parkville 3010, Australia.
| | - Evan J Bieske
- School of Chemistry, University of Melbourne, Parkville 3010, Australia.
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2
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Marlton SJP, Liu C, Bieske EJ. Bond dissociation energy of FeCr+ determined through threshold photodissociation in a cryogenic ion trap. J Chem Phys 2024; 160:034301. [PMID: 38226822 DOI: 10.1063/5.0188157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 12/20/2023] [Indexed: 01/17/2024] Open
Abstract
The bond dissociation energy of FeCr+ is measured using resonance enhanced photodissociation spectroscopy in a cryogenic ion trap. The onset for FeCr+ → Fe + Cr+ photodissociation occurs well above the lowest Cr+(6S, 3d5) + Fe(5D, 3d64s2) dissociation limit. In contrast, the higher energy FeCr+ → Fe+ + Cr photodissociation process exhibits an abrupt onset at the energy of the Cr(7S, 3d54s1) + Fe+(6D, 3d64s1) limit, enabling accurate dissociation energies to be extracted: D(Fe-Cr+) = 1.655 ± 0.006 eV and D(Fe+-Cr) = 2.791 ± 0.006 eV. The measured D(Fe-Cr+) bond energy is 10%-20% larger than predictions from accompanying CAM (Coulomb Attenuated Method)-B3LYP and NEVPT2 and coupled cluster singles, doubles, and perturbative triples electronic structure calculations, which give D(Fe-Cr+) = 1.48, 1.40, and 1.35 eV, respectively. The study emphasizes that an abrupt increase in the photodissociation yield at threshold requires that the molecule possesses a dense manifold of optically accessible, coupled electronic states adjacent to the dissociation asymptote. This condition is not met for the lowest Cr+(6S, 3d5) + Fe(5D, 3d64s2) dissociation limit of FeCr+ but is satisfied for the higher energy Cr(7S, 3d54s1) + Fe+(6D, 3d64s1) dissociation limit.
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Affiliation(s)
- Samuel J P Marlton
- School of Chemistry, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Chang Liu
- School of Chemistry, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Melbourne, Victoria 3010, Australia
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3
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Catani KJ, Bartlett NI, Scholz MS, Muller G, Taylor PR, Bieske EJ. Charge transfer transitions of the O2+-Ar and O2+-N2 complexes. J Chem Phys 2023; 159:024308. [PMID: 37439469 DOI: 10.1063/5.0152570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/26/2023] [Indexed: 07/14/2023] Open
Abstract
Electronic transitions are observed for the O2+-Ar and O2+-N2 complexes over the 225-350 nm range. The transitions are not associated with recognized electronic band systems of the respective atomic and diatomic constituents (Ar+, Ar, O2+, O2, N2+, and N2) but rather are due to charge transfer transitions. Onsets of the O2+-Ar and O2+-N2 band systems occur at 3.68 and 3.62 eV, respectively, corresponding to the difference in the ionization potentials of Ar and O2 (3.69 eV), and N2 and of O2 (3.51 eV), suggesting the band systems arise from intramolecular charge transfer transitions to states correlating with O2(X3Σg-) + Ar+ (2Pu) and O2(X3Σg-) + N2+(X2Σg+) limits, respectively. The dominant vibronic progressions have ωe values of 1565 cm-1 for O2+-Ar and 1532 cm-1 for O2+-N2, reasonably close to the value for the neutral O2 molecule in its X3Σg- state (1580 cm-1). Higher energy band systems for O2+-Ar and O2+-N2 are assigned to transitions to states correlating with the O2 (a1Δg) + Ar+ (2Pu) and O2 (a1Δg) + N2+(X2Σg+) limits, respectively.
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Affiliation(s)
- Katherine J Catani
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | | | - Michael S Scholz
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Giel Muller
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Peter R Taylor
- Health Science Platform, Tianjin University, A203, Bldg. 24, 92 Weijin Rd., Nankai Dist., Tianjin 300072, China
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
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4
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Marlton SJP, Liu C, Watkins P, Buntine JT, Bieske EJ. Bond dissociation energies for Fe2+, Fe2O+, and Fe2O2+ clusters determined through threshold photodissociation in a cryogenic ion trap. J Chem Phys 2023; 159:024302. [PMID: 37428057 DOI: 10.1063/5.0155548] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 06/15/2023] [Indexed: 07/11/2023] Open
Abstract
Understanding and controlling the chemical behavior of iron and iron oxide clusters requires accurate thermochemical data, which, because of the complex electronic structure of transition metal clusters, can be difficult to calculate reliably. Here, dissociation energies for Fe2+, Fe2O+, and Fe2O2+ are measured using resonance enhanced photodissociation of clusters contained in a cryogenically cooled ion trap. The photodissociation action spectrum of each species exhibits an abrupt onset for the production of Fe+ photofragments from which bond dissociation energies are deduced for Fe2+ (2.529 ± 0.006 eV), Fe2O+ (3.503 ± 0.006 eV), and Fe2O2+ (4.104 ± 0.006 eV). Using previously measured ionization potentials and electron affinities for Fe and Fe2, bond dissociation energies are determined for Fe2 (0.93 ± 0.01 eV) and Fe2- (1.68 ± 0.01 eV). Measured dissociation energies are used to derive heats of formation ΔfH0(Fe2+) = 1344 ± 2 kJ/mol, ΔfH0(Fe2) = 737 ± 2 kJ/mol, ΔfH0(Fe2-) = 649 ± 2 kJ/mol, ΔfH0(Fe2O+) = 1094 ± 2 kJ/mol, and ΔfH0(Fe2O2+) = 853 ± 21 kJ/mol. The Fe2O2+ ions studied here are determined to have a ring structure based on drift tube ion mobility measurements prior to their confinement in the cryogenic ion trap. The photodissociation measurements significantly improve the accuracy of basic thermochemical data for these small, fundamental iron and iron oxide clusters.
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Affiliation(s)
- Samuel J P Marlton
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Chang Liu
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Patrick Watkins
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Jack T Buntine
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
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5
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Marlton SJP, Buntine JT, Watkins P, Liu C, Jacovella U, Carrascosa E, Bull JN, Bieske EJ. Probing Colossal Carbon Rings. J Phys Chem A 2023; 127:1168-1178. [PMID: 36703560 DOI: 10.1021/acs.jpca.2c07068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Carbon aggregates containing between 10 and 30 atoms preferentially arrange themselves as planar rings. To learn more about this exotic allotrope of carbon, electronic spectra are measured for even cyclo[n]carbon radical cations (C14+-C36+) using two-color photodissociation action spectroscopy. To eliminate spectral contributions from other isomers, the target cyclo[n]carbon radical cations are isomer-selected using a drift tube ion mobility spectrometer prior to spectroscopic interrogation. The electronic spectra exhibit sharp transitions spanning the visible and near-infrared spectral regions with the main absorption band shifting progressively to longer wavelength by ≈100 nm for every additional two carbon atoms. This behavior is rationalized with a Hückel theory model describing the energies of the in-plane and out-of-plane π orbitals. Photoexcitation of smaller carbon rings leads preferentially to neutral C3 and C5 loss, whereas rings larger than C24+ tend to also decompose into two smaller rings, which, when possible, have aromatic stability. Generally, the observed charged photofragments correspond to low energy fragment pairs, as predicted by density functional theory calculations (CAM-B3LYP-D3(BJ)/cc-pVDZ). Using action spectroscopy it is confirmed that C14+ and C18+ photofragments from C28+ rings have cyclic structures.
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Affiliation(s)
- Samuel J P Marlton
- School of Chemistry, The University of Melbourne, Victoria, Australia3010
| | - Jack T Buntine
- School of Chemistry, The University of Melbourne, Victoria, Australia3010
| | - Patrick Watkins
- School of Chemistry, The University of Melbourne, Victoria, Australia3010
| | - Chang Liu
- School of Chemistry, The University of Melbourne, Victoria, Australia3010
| | - Ugo Jacovella
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405Orsay, France
| | - Eduardo Carrascosa
- Bruker Daltonics GmbH & Co. KG, Fahrenheitstrasse 4, 28359Bremen, Germany
| | - James N Bull
- School of Chemistry, Norwich Research Park, University of East Anglia, NorwichNR4 7TJ, United Kingdom
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Victoria, Australia3010
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6
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Ashworth E, Coughlan NJA, Hopkins WS, Bieske EJ, Bull JN. Excited-State Barrier Controls E → Z Photoisomerization in p-Hydroxycinnamate Biochromophores. J Phys Chem Lett 2022; 13:9028-9034. [PMID: 36149746 PMCID: PMC9549896 DOI: 10.1021/acs.jpclett.2c02613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
Molecules based on the deprotonated p-hydroxycinnamate moiety are widespread in nature, including serving as UV filters in the leaves of plants and as the biochromophore in photoactive yellow protein. The photophysical behavior of these chromophores is centered around a rapid E → Z photoisomerization by passage through a conical intersection seam. Here, we use photoisomerization and photodissociation action spectroscopies with deprotonated 4-hydroxybenzal acetone (pCK-) to characterize a wavelength-dependent bifurcation between electron autodetachment (spontaneous ejection of an electron from the S1 state because it is situated in the detachment continuum) and E → Z photoisomerization. While autodetachment occurs across the entire S1(ππ*) band (370-480 nm), E → Z photoisomerization occurs only over a blue portion of the band (370-430 nm). No E → Z photoisomerization is observed when the ketone functional group in pCK- is replaced with an ester or carboxylic acid. The wavelength-dependent bifurcation is consistent with potential energy surface calculations showing that a barrier separates the Franck-Condon region from the E → Z isomerizing conical intersection. The barrier height, which is substantially higher in the gas phase than in solution, depends on the functional group and governs whether E → Z photoisomerization occurs more rapidly than autodetachment.
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Affiliation(s)
- Eleanor
K. Ashworth
- School
of Chemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Neville J. A. Coughlan
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- WaterMine
Innovation, Inc., Waterloo, Ontario N0B 2T0, Canada
| | - W. Scott Hopkins
- Department
of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- WaterMine
Innovation, Inc., Waterloo, Ontario N0B 2T0, Canada
| | - Evan J. Bieske
- School
of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
| | - James N. Bull
- School
of Chemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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7
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Marlton SJP, Buntine JT, Liu C, Watkins P, Jacovella U, Carrascosa E, Bull JN, Bieske EJ. Disentangling Electronic Spectra of Linear and Cyclic Hydrogenated Carbon Cluster Cations, C 2n+1H + ( n = 3–10). J Phys Chem A 2022; 126:6678-6685. [DOI: 10.1021/acs.jpca.2c05051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Samuel J. P. Marlton
- School of Chemistry, The University of Melbourne, 3010 Parkville, Victoria, Australia
| | - Jack T. Buntine
- School of Chemistry, The University of Melbourne, 3010 Parkville, Victoria, Australia
| | - Chang Liu
- School of Chemistry, The University of Melbourne, 3010 Parkville, Victoria, Australia
| | - Patrick Watkins
- School of Chemistry, The University of Melbourne, 3010 Parkville, Victoria, Australia
| | - Ugo Jacovella
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
| | - Eduardo Carrascosa
- Bruker Daltonics GmbH & Co. KG, Fahrenheitstrasse 4, 28359 Bremen, Germany
| | - James N. Bull
- School of Chemistry, University of East Anglia, Norwich Research Park, NR4 7TJ Norwich, U.K
| | - Evan J. Bieske
- School of Chemistry, The University of Melbourne, 3010 Parkville, Victoria, Australia
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8
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Buntine JT, Carrascosa E, Bull JN, Muller G, Jacovella U, Glasson CR, Vamvounis G, Bieske EJ. Photo-induced 6π-electrocyclisation and cycloreversion of isolated dithienylethene anions. Phys Chem Chem Phys 2022; 24:16628-16636. [PMID: 35766319 DOI: 10.1039/d2cp01240e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The diarylethene chromophore is commonly used in light-triggered molecular switches. The chromophore undergoes reversible 6π-electrocyclisation (ring closing) and cycloreversion (ring opening) reactions upon exposure to UV and visible light, respectively, providing bidirectional photoswitching. Here, we investigate the gas-phase photoisomerisation of meta- (m) and para- (p) substituted dithienylethene carboxylate anions (DTE-) using tandem ion mobility mass spectrometry coupled with laser excitation. The ring-closed forms of p-DTE- and m-DTE- are found to undergo cycloreversion in the gas phase with maximum responses associated with bands in the visible (λmax ≈ 600 nm) and the ultraviolet (λmax ≈ 360 nm). The ring-open p-DTE- isomer undergoes 6π-electrocyclisation in the ultraviolet region at wavelengths shorter than 350 nm, whereas no evidence is found for the corresponding electrocyclisation of ring-open m-DTE-, a situation attributed to the fact that the antiparallel geometry required for electrocyclisation of m-DTE- is energetically disfavoured. This highlights the influence of the carboxylate substitution position on the photochemical properties of DTE molecules. We find no evidence for the formation in the gas phase of the undesirable cyclic byproduct, which causes fatigue of DTE photoswitches in solution.
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Affiliation(s)
- Jack T Buntine
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Eduardo Carrascosa
- Bruker Daltonics GmbH & Co. KG, Fahrenheitstrasse 4, 28359 Bremen, Germany
| | - James N Bull
- School of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, UK
| | - Giel Muller
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Ugo Jacovella
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - Christopher R Glasson
- Environmental Research Institute, School of Science, University of Waikato, Tauranga, 3110, New Zealand
| | - George Vamvounis
- College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia.
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9
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Buntine JT, Carrascosa E, Bull JN, Jacovella U, Cotter MI, Watkins P, Liu C, Scholz MS, Adamson BD, Marlton SJP, Bieske EJ. An ion mobility mass spectrometer coupled with a cryogenic ion trap for recording electronic spectra of charged, isomer-selected clusters. Rev Sci Instrum 2022; 93:043201. [PMID: 35489918 DOI: 10.1063/5.0085680] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Infrared and electronic spectra are indispensable for understanding the structural and energetic properties of charged molecules and clusters in the gas phase. However, the presence of isomers can potentially complicate the interpretation of spectra, even if the target molecules or clusters are mass-selected beforehand. Here, we describe an instrument for spectroscopically characterizing charged molecular clusters that have been selected according to both their isomeric form and their mass-to-charge ratio. Cluster ions generated by laser ablation of a solid sample are selected according to their collision cross sections with helium buffer gas using a drift tube ion mobility spectrometer and their mass-to-charge ratio using a quadrupole mass filter. The mobility- and mass-selected target ions are introduced into a cryogenically cooled, three-dimensional quadrupole ion trap where they are thermalized through inelastic collisions with an inert buffer gas (He or He/N2 mixture). Spectra of the molecular ions are obtained by tagging them with inert atoms or molecules (Ne and N2), which are dislodged following resonant excitation of an electronic transition, or by photodissociating the cluster itself following absorption of one or more photons. An electronic spectrum is generated by monitoring the charged photofragment yield as a function of wavelength. The capacity of the instrument is illustrated with the resonance-enhanced photodissociation action spectra of carbon clusters (Cn +) and polyacetylene cations (HC2nH+) that have been selected according to the mass-to-charge ratio and collision cross section with He buffer gas and of mass-selected Au2 + and Au2Ag+ clusters.
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Affiliation(s)
- Jack T Buntine
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Eduardo Carrascosa
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - James N Bull
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Ugo Jacovella
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Mariah I Cotter
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Patrick Watkins
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Chang Liu
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Michael S Scholz
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Brian D Adamson
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Samuel J P Marlton
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
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10
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Patra S, San Vicente Veliz JC, Koner D, Bieske EJ, Meuwly M. Photodissociation dynamics of N3+. J Chem Phys 2022; 156:124307. [DOI: 10.1063/5.0085081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The photodissociation dynamics of [Formula: see text] excited from its (linear) 3[Formula: see text]/(bent) 3A″ ground to the first excited singlet and triplet states is investigated. Three-dimensional potential energy surfaces for the 1A′, 1A″, and 3A′ electronic states, correlating with the 1Δg and 3Πu states in linear geometry, for [Formula: see text] are constructed using high-level electronic structure calculations and represented as reproducing kernels. The reference ab initio energies are calculated at the MRCI+Q/aug-cc-pVTZ level of theory. For following the photodissociation dynamics in the excited states, rotational and vibrational distributions P( v′) and P( j′) for the N2 product are determined from vertically excited ground state distributions. Due to the different shapes of the ground state 3A″ potential energy surface and the excited states, appreciable angular momentum j′ ∼ 60 is generated in diatomic fragments. The lifetimes in the excited states extend to at least 50 ps. Notably, results from sampling initial conditions from a thermal ensemble and from the Wigner distribution of the ground state wavefunction are comparable.
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Affiliation(s)
- Sarbani Patra
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | | | - Debasish Koner
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati, Karakambadi Road, Mangalam, Tirupati 517507, Andhra Pradesh, India
| | - Evan J. Bieske
- Department of Chemistry, University of Melbourne, Parkville 3010, Australia
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
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11
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McKinnon BI, Marlton SJP, Ucur B, Bieske EJ, Poad BLJ, Blanksby SJ, Trevitt AJ. Actinic Wavelength Action Spectroscopy of the IO - Reaction Intermediate. J Phys Chem Lett 2021; 12:11939-11944. [PMID: 34878800 DOI: 10.1021/acs.jpclett.1c03456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Iodinate anions are important in the chemistry of the atmosphere where they are implicated in ozone depletion and particle formation. The atmospheric chemistry of iodine is a complex overlay of neutral-neutral, ion-neutral, and photochemical processes, where many of the reactions and intermediates remain poorly characterized. This study targets the visible spectroscopy and photostability of the gas-phase hypoiodite anion (IO-), the initial product of the I- + O3 reaction, by mass spectrometry equipped with resonance-enhanced photodissociation and total ion-loss action spectroscopies. It is shown that IO- undergoes photodissociation to I- + O (3P) over 637-459 nm (15700-21800 cm-1) because of excitation to the bound first singlet excited state. Electron photodetachment competes with photodissociation above the electron detachment threshold of IO- at 521 nm (19200 cm-1) with peaks corresponding to resonant autodetachment involving the singlet excited state and the ground state of neutral IO possibly mediated by a dipole-bound state.
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Affiliation(s)
- Benjamin I McKinnon
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Samuel J P Marlton
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Boris Ucur
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Berwyck L J Poad
- Central Analytical Research Facility, Queensland University of Technology, Brisbane 4001, Australia
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4001, Australia
| | - Stephen J Blanksby
- Central Analytical Research Facility, Queensland University of Technology, Brisbane 4001, Australia
- School of Chemistry and Physics, Queensland University of Technology, Brisbane 4001, Australia
| | - Adam J Trevitt
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales 2522, Australia
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12
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Bull JN, Anstöter CS, Stockett MH, Clarke CJ, Gibbard JA, Bieske EJ, Verlet JRR. Nonadiabatic Dynamics between Valence, Nonvalence, and Continuum Electronic States in a Heteropolycyclic Aromatic Hydrocarbon. J Phys Chem Lett 2021; 12:11811-11816. [PMID: 34870432 DOI: 10.1021/acs.jpclett.1c03532] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
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 imaging with a heteropolycyclic aromatic hydrocarbon (hetero-PAH) anion, deprotonated 1-pyrenol, is used to demonstrate a subpicosecond (τ1 = 160 ± 20 fs) valence to dipole-bound state internal conversion following excitation of the origin transition of the first valence-localized excited state. The internal conversion dynamics are evident in the photoelectron spectra and in the photoelectron angular distributions (β2 values) as the electronic character of the excited state population changes from valence to nonvalence. The dipole-bound state subsequently decays through mode-specific vibrational autodetachment with a lifetime τ2 = 11 ± 2 ps. These internal conversion and autodetachment dynamics are likely common in molecular anions but difficult to fingerprint due to the transient existence of the dipole-bound state. Potential implications of the present excited state dynamics for interstellar hetero-PAH anion formation are discussed.
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Affiliation(s)
- James N Bull
- School of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Cate S Anstöter
- Department of Chemistry, Temple University, 1901 N 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Mark H Stockett
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - Connor J Clarke
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Jemma A Gibbard
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Evan J Bieske
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
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13
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Buntine JT, Cotter MI, Jacovella U, Liu C, Watkins P, Carrascosa E, Bull JN, Weston L, Muller G, Scholz MS, Bieske EJ. Electronic spectra of positively charged carbon clusters-C 2n + (n = 6-14). J Chem Phys 2021; 155:214302. [PMID: 34879679 DOI: 10.1063/5.0070502] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Electronic spectra are measured for mass-selected C2n +(n = 6-14) clusters over the visible and near-infrared spectral range through resonance enhanced photodissociation of clusters tagged with N2 molecules in a cryogenic ion trap. The carbon cluster cations are generated through laser ablation of a graphite disk and can be selected according to their collision cross section with He buffer gas and their mass prior to being trapped and spectroscopically probed. The data suggest that the C2n +(n = 6-14) clusters have monocyclic structures with bicyclic structures becoming more prevalent for C22 + and larger clusters. The C2n + electronic spectra are dominated by an origin transition that shifts linearly to a longer wavelength with the number of carbon atoms and associated progressions involving excitation of ring deformation vibrational modes. Bands for C12 +, C16 +, C20 +, C24 +, and C28 + are relatively broad, possibly due to rapid non-radiative decay from the excited state, whereas bands for C14 +, C18 +, C22 +, and C26 + are narrower, consistent with slower non-radiative deactivation.
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Affiliation(s)
- Jack T Buntine
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Mariah I Cotter
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Ugo Jacovella
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Chang Liu
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Patrick Watkins
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Eduardo Carrascosa
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - James N Bull
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Luke Weston
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Giel Muller
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Michael S Scholz
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
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14
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Carrascosa E, Bull JN, Martínez-Núñez E, Scholz MS, Buntine JT, Bieske EJ. Photoisomerization of Linear and Stacked Isomers of a Charged Styryl Dye: A Tandem Ion Mobility Study. J Am Soc Mass Spectrom 2021; 32:2842-2851. [PMID: 34787413 PMCID: PMC8640989 DOI: 10.1021/jasms.1c00264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/21/2021] [Accepted: 11/01/2021] [Indexed: 06/13/2023]
Abstract
The photoisomerization behavior of styryl 9M, a common dye used in material sciences, is investigated using tandem ion mobility spectrometry (IMS) coupled with laser spectroscopy. Styryl 9M has two alkene linkages, potentially allowing for four geometric isomers. IMS measurements demonstrate that at least three geometric isomers are generated using electrospray ionization with the most abundant forms assigned to a combination of EE (major) and ZE (minor) geometric isomers, which are difficult to distinguish using IMS as they have similar collision cross sections. Two additional but minor isomers are generated by collisional excitation of the electrosprayed styryl 9M ions and are assigned to the EZ and ZZ geometric isomers, with the latter predicted to have a π-stacked configuration. The isomer assignments are supported through calculations of equilibrium structures, collision cross sections, and statistical isomerization rates. Photoexcitation of selected isomers using an IMS-photo-IMS strategy shows that each geometric isomer photoisomerizes following absorption of near-infrared and visible light, with the EE isomer possessing a S1 ← S0 electronic transition with a band maximum near 680 nm and shorter wavelength S2 ← S0 electronic transition with a band maximum near 430 nm. The study demonstrates the utility of the IMS-photo-IMS strategy for providing fundamental gas-phase photochemical information on molecular systems with multiple isomerizable bonds.
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Affiliation(s)
- Eduardo Carrascosa
- School
of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - James N. Bull
- School
of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- School
of Chemistry, Norwich Research Park, University
of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Emilio Martínez-Núñez
- Departamento
de Química Física, Universidade
de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Michael S. Scholz
- School
of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Jack T. Buntine
- School
of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Evan J. Bieske
- School
of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
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15
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Abstract
Dye molecules based on the xanthene moiety are widely used as fluorescent probes in bioimaging and technological applications due to their large absorption cross-section for visible light and high fluorescence quantum yield. These applications require a clear understanding of the dye's inherent photophysics and the effect of a condensed-phase environment. Here, the gas-phase photophysics of the rose bengal doubly deprotonated dianion [RB - 2H]2-, deprotonated monoanion [RB - H]-, and doubly deprotonated radical anion [RB - 2H]•- is investigated using photodetachment, photoelectron, and dispersed fluorescence action spectroscopies, and tandem ion mobility spectrometry (IMS) coupled with laser excitation. For [RB - 2H]2-, photodetachment action spectroscopy reveals a clear band in the visible (450-580 nm) with vibronic structure. Electron affinity and repulsive Coulomb barrier (RCB) properties of the dianion are characterized using frequency-resolved photoelectron spectroscopy, revealing a decreased RCB compared with that of fluorescein dianions due to electron delocalization over halogen atoms. Monoanions [RB - H]- and [RB - 2H]•- differ in nominal mass by 1 Da but are difficult to study individually using action spectroscopies that isolate target ions using low-resolution mass spectrometry. This work shows that the two monoanions are readily distinguished and probed using the IMS-photo-IMS and photo-IMS-photo-IMS strategies, providing distinct but overlapping photodissociation action spectra in the visible spectral range. Gas-phase fluorescence was not detected from photoexcited [RB - 2H]2- due to rapid electron ejection. However, both [RB - H]- and [RB - 2H]•- show a weak fluorescence signal. The [RB - H]- action spectra show a large Stokes shift of ∼1700 cm-1, while the [RB - 2H]•- action spectra show no appreciable Stokes shift. This difference is explained by considering geometries of the ground and fluorescing states.
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Affiliation(s)
- Mark H Stockett
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Christina Kjær
- Department of Physics and Astronomy, Aarhus University, Aarhus 8000, Denmark
| | - Steven Daly
- Université Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumiére Matiére UMR 5306, F-69100 Villeurbanne, France
| | - Evan J Bieske
- School of Chemistry, University of Melbourne, Parkville VIC 3010, Australia
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | | | - James N Bull
- School of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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16
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Abstract
The structure and properties of the tropylium cation (C7H7+) have enthralled chemists since the prediction by Hückel in 1931 of the remarkable stability for cyclic, aromatic molecules containing six π-electrons. However, probing and understanding the excited electronic states of the isolated tropylium cation have proved challenging, as the accessible electronic transitions are weak, and there are difficulties in creating appreciable populations of the tropylium cation in the gas phase. Here, we present the first gas-phase S1 ←S0 electronic spectrum of the tropylium cation, recorded by resonance-enhanced photodissociation of weakly bound tropylium-Ar complexes. We demonstrate that the intensity of the symmetry-forbidden S1 ←S0 transition arises from Herzberg-Teller vibronic coupling between the S1 and S2 electronic states mediated by vibrational modes of e2' and e3' symmetry. The main geometry change upon excitation involves elongation of the C-C bonds. Multiconfigurational ab initio calculations predict that the S1 excited state is affected by the dynamical Jahn-Teller effect, which should lead to the appearance of additional weak bands that may be apparent in higher-resolution electronic spectra.
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Affiliation(s)
- Ugo Jacovella
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Michael S Scholz
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
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17
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Jacovella U, Carrascosa E, Buntine JT, Ree N, Mikkelsen KV, Jevric M, Moth-Poulsen K, Bieske EJ. Photo- and Collision-Induced Isomerization of a Charge-Tagged Norbornadiene-Quadricyclane System. J Phys Chem Lett 2020; 11:6045-6050. [PMID: 32539402 PMCID: PMC7416310 DOI: 10.1021/acs.jpclett.0c01198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 06/15/2020] [Indexed: 06/11/2023]
Abstract
Molecular photoswitches based on the norbornadiene-quadricylane (NBD-QC) couple have been proposed as key elements of molecular solar thermal energy storage schemes. To characterize the intrinsic properties of such systems, reversible isomerization of a charge-tagged NBD-QC carboxylate couple is investigated in a tandem ion mobility mass spectrometer, using light to induce intramolecular [2 + 2] cycloaddition of NBD carboxylate to form the QC carboxylate and driving the back reaction with molecular collisions. The NBD carboxylate photoisomerization action spectrum recorded by monitoring the QC carboxylate photoisomer extends from 290 to 360 nm with a maximum at 315 nm, and in the longer wavelength region resembles the NBD carboxylate absorption spectrum recorded in solution. Key structural and photochemical properties of the NBD-QC carboxylate system, including the gas-phase absorption spectrum and the energy storage capacity, are determined through computational studies using density functional theory.
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Affiliation(s)
- Ugo Jacovella
- School
of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Eduardo Carrascosa
- School
of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Jack T. Buntine
- School
of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Nicolai Ree
- Department
of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Kurt V. Mikkelsen
- Department
of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Martyn Jevric
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, 41296 Gothenburg, Sweden
| | - Kasper Moth-Poulsen
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, 41296 Gothenburg, Sweden
| | - Evan J. Bieske
- School
of Chemistry, The University of Melbourne, Victoria 3010, Australia
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18
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Koner D, Schwilk M, Patra S, Bieske EJ, Meuwly M. N3+: Full-dimensional ground state potential energy surface, vibrational energy levels, and dynamics. J Chem Phys 2020; 153:044302. [DOI: 10.1063/5.0011957] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Debasish Koner
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Max Schwilk
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Sarbani Patra
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Evan J. Bieske
- Department of Chemistry, University of Melbourne, Parkville 3010, Australia
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
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19
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Carrascosa E, Petermayer C, Scholz MS, Bull JN, Dube H, Bieske EJ. Reversible Photoswitching of Isolated Ionic Hemiindigos with Visible Light. Chemphyschem 2020; 21:680-685. [PMID: 31736199 PMCID: PMC7277040 DOI: 10.1002/cphc.201900963] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Indexed: 01/06/2023]
Abstract
Indigoid chromophores have emerged as versatile molecular photoswitches, offering efficient reversible photoisomerization upon exposure to visible light. Here we report synthesis of a new class of permanently charged hemiindigos (HIs) and characterization of photochemical properties in gas phase and solution. Gas-phase studies, which involve exposing mobility-selected ions in a tandem ion mobility mass spectrometer to tunable wavelength laser radiation, demonstrate that the isolated HI ions are photochromic and can be reversibly photoswitched between Z and E isomers. The Z and E isomers have distinct photoisomerization response spectra with maxima separated by 40-80 nm, consistent with theoretical predictions for their absorption spectra. Solvation of the HI molecules in acetonitrile displaces the absorption bands to lower energy. Together, gas-phase action spectroscopy and solution NMR and UV/Vis absorption spectroscopy represent a powerful approach for studying the intrinsic photochemical properties of HI molecular switches.
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Affiliation(s)
- Eduardo Carrascosa
- School of ChemistryThe University of Melbourne3010Parkville (VIC)Australia
| | - Christian Petermayer
- Department für Chemie and Munich Center for Integrated Protein Science CIPSMLudwig-Maximilians-Universität München81377MunichGermany
| | - Michael S. Scholz
- School of ChemistryThe University of Melbourne3010Parkville (VIC)Australia
| | - James N. Bull
- School of ChemistryThe University of Melbourne3010Parkville (VIC)Australia
- School of Chemistry, Norwich Research ParkUniversity of East AngliaNorwichNR4 7TJUnited Kingdom
| | - Henry Dube
- Department für Chemie and Munich Center for Integrated Protein Science CIPSMLudwig-Maximilians-Universität München81377MunichGermany
| | - Evan J. Bieske
- School of ChemistryThe University of Melbourne3010Parkville (VIC)Australia
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20
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Muller G, Jacovella U, Catani KJ, da Silva G, Bieske EJ. Electronic Spectrum and Photodissociation Chemistry of the 1-Butyn-3-yl Cation, H 3CCHCCH . J Phys Chem A 2020; 124:2366-2371. [PMID: 32119779 DOI: 10.1021/acs.jpca.9b11810] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The B̃1A' ← X̃1A' electronic spectra of the 1-butyn-3-yl cation (H3CCHCCH+) and the H3CCHCCH+-Ne and H3CCHCCH+-Ar complexes are measured using resonance enhanced photodissociation over the 245-285 nm range, with origin transitions occurring at 35936, 35930, and 35928 cm-1, respectively. Vibronic bands are assigned based on quantum chemical calculations and comparison of the spectra with those of the related linear methyl propargyl (H3C4H2+) and propargyl (H2C3H+) cations. The photofragment ions are C2H3+ (major) and C4H3+ (minor), with the preference for C2H3+ consistent with master equation simulations for a mechanism that involves rapid electronic deactivation and dissociation on the ground state potential energy surface.
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Affiliation(s)
- Giel Muller
- School of Chemistry, The University of Melbourne, Melbourne, Victoria, Australia 3010
| | - Ugo Jacovella
- School of Chemistry, The University of Melbourne, Melbourne, Victoria, Australia 3010
| | - Katherine J Catani
- School of Chemistry, The University of Melbourne, Melbourne, Victoria, Australia 3010
| | - Gabriel da Silva
- Department of Chemical Engineering, The University of Melbourne, Melbourne, Victoria, Australia 3010
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Melbourne, Victoria, Australia 3010
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21
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Carrascosa E, Bull JN, Buntine JT, da Silva G, Santos PF, Bieske EJ. Near-infrared reversible photoswitching of an isolated azobenzene-stilbene dye. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2019.137065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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22
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Ma HZ, McKay AI, Mravak A, Scholz MS, White JM, Mulder RJ, Bieske EJ, Bonačić-Koutecký V, O'Hair RAJ. Structural characterization and gas-phase studies of the [Ag 10H 8(L) 6] 2+ nanocluster dication. Nanoscale 2019; 11:22880-22889. [PMID: 31763652 DOI: 10.1039/c9nr08321a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The reactions between silver salts and borohydrides produce a rich set of products that range from discrete mononuclear compounds through to silver nanoparticles and colloids. Previous studies using electrospray ionization mass spectrometry (ESI-MS) to track the cationic products in solutions containing sodium borohydride, silver(i) tetrafluoroborate and the bisphosphine ligands, L, bis(diphenylphosphino)methane (dppm) and bis(diphenylphosphino)amine (dppa) have identified the dications [Ag10H8(L)6]2+. Here we isolate and structurally characterize [Ag10H8(dppa)6](BF4)2, and [Ag10H8(dppa)6](NO3)2via X-ray crystallography. Both dications have nearly identical structural features consisting of a Ag10 scaffold with the atoms lying on vertices of a bicapped square antiprism. DFT calculations were carried out to suggest potential sites for the hydrides. Ion-mobility mass spectrometry experiments revealed that [Ag10H8(dppa)6]2+ and [Ag10H8(dppm)6]2+ have similar collision cross sections, while multistage mass spectrometry experiments were used to compare their unimolecular gas-phase chemistry. Although the same initial sequential ligand loss followed by cluster fission and H2 evolution is observed, the more acidic N-H of the dppa provides a more labile H for H2 loss and H/D scrambling processes as revealed by isotope labelled experiments.
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Affiliation(s)
- Howard Z Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Alasdair I McKay
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Antonija Mravak
- Center of Excellence for Science and Technology-Integration of Mediterranean Region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST), University of Split, Poljička cesta 35, Split 21000, Croatia
| | - Michael S Scholz
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Jonathan M White
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Roger J Mulder
- CSIRO Manufacturing, Research Way, Clayton, Victoria 3168, Australia
| | - Evan J Bieske
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
| | - Vlasta Bonačić-Koutecký
- Center of Excellence for Science and Technology-Integration of Mediterranean Region (STIM) at Interdisciplinary Center for Advanced Sciences and Technology (ICAST), University of Split, Poljička cesta 35, Split 21000, Croatia and Chemistry Department, Humboldt University of Berlin, Brook-Taylor-Strasse 2, Berlin 12489, Germany
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Rd, Parkville, Victoria 3010, Australia.
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23
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Muller G, Catani KJ, Scholz MS, Jacovella U, Bartlett NI, Bieske EJ. Electronic Spectra of Diacetylene Cations (HC 4H +) Tagged with Ar and N 2. J Phys Chem A 2019; 123:7228-7236. [DOI: 10.1021/acs.jpca.9b05996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Giel Muller
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Katherine J. Catani
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Michael S. Scholz
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Ugo Jacovella
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Nastasia I. Bartlett
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Evan J. Bieske
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
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24
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Bull JN, West CW, Anstöter CS, da Silva G, Bieske EJ, Verlet JRR. Ultrafast photoisomerisation of an isolated retinoid. Phys Chem Chem Phys 2019; 21:10567-10579. [PMID: 31073587 DOI: 10.1039/c9cp01624d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The photoinduced excited state dynamics of gas-phase trans-retinoate (deprotonated trans-retinoic acid, trans-RA-) are studied using tandem ion mobility spectrometry coupled with laser spectroscopy, and frequency-, angle- and time-resolved photoelectron imaging. Photoexcitation of the bright S3(ππ*) ← S0 transition leads to internal conversion to the S1(ππ*) state on a ≈80 fs timescale followed by recovery of S0 and concomitant isomerisation to give the 13-cis (major) and 9-cis (minor) photoisomers on a ≈180 fs timescale. The sub-200 fs stereoselective photoisomerisation parallels that for the retinal protonated Schiff base chromophore in bacteriorhodopsin. Measurements on trans-RA- in methanol using the solution photoisomerisation action spectroscopy technique show that 13-cis-RA- is also the principal photoisomer, although the 13-cis and 9-cis photoisomers are formed with an inverted branching ratio with photon energy in methanol when compared with the gas phase, presumably due to solvent-induced modification of potential energy surfaces and inhibition of electron detachment processes. Comparison of the gas-phase time-resolved data with transient absorption spectroscopy measurements on retinoic acid in methanol suggest that photoisomerisation is roughly six times slower in solution. This work provides clear evidence that solvation significantly affects the photoisomerisation dynamics of retinoid molecules.
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Affiliation(s)
- James N Bull
- School of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, UK.
| | - Christopher W West
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Cate S Anstöter
- Department of Chemistry, Durham University, Durham DH1 3LE, UK
| | - Gabriel da Silva
- Department of Chemical Engineering, University of Melbourne, Parkville, VIC 3010, Australia
| | - Evan J Bieske
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, UK
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25
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Bull JN, Silva GD, Scholz MS, Carrascosa E, Bieske EJ. Photoinitiated Intramolecular Proton Transfer in Deprotonated para-Coumaric Acid. J Phys Chem A 2019; 123:4419-4430. [DOI: 10.1021/acs.jpca.9b02023] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- James N. Bull
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
- School of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Gabriel da Silva
- Department of Chemical Engineering, University of Melbourne, Parkville, VIC 3010, Australia
| | - Michael S. Scholz
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
| | - Eduardo Carrascosa
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
| | - Evan J. Bieske
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
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26
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Abstract
The unimolecular reactions of C7H8+ radical cations are among those most studied by mass spectrometry, especially the rearrangement of toluene and cycloheptatriene molecular ions, which are directly connected to the formation of benzylium and tropylium cations. This study reveals important new isomers and isomerization pathways on the C7H8+ potential energy surface, through the application of gas-phase electronic photodissociation spectroscopy in conjunction with ab initio calculations. Presented are the first gas-phase vibrationally resolved electronic spectra of the o-isotoluene, norcaradiene, bicyclo[3.2.0]hepta-2,6-diene radical cations, and ring-opened products from cyclic C7H8+ species. The isomerization route from the norbornadiene radical cation to the toluene radical cation, which competes with isomerization to the bicyclo[2.2.1]hepta-2-ene-5-yl-7-ylium radical cation, is identified. Further, this work expands understanding of the C7H8+ potential energy surface by connecting spiro[2.4]hepta-4,6-diene and acyclic 1,2,4,6-heptatetraene radical cations, and confirms the important role of the o-isotoluene radical cation in the interconversion pathways of C7H8+ species.
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Affiliation(s)
- Ugo Jacovella
- School of Chemistry , The University of Melbourne , Victoria 3010 , Australia
| | - Gabriel da Silva
- Department of Chemical Engineering , The University of Melbourne , Victoria 3010 , Australia
| | - Evan J Bieske
- School of Chemistry , The University of Melbourne , Victoria 3010 , Australia
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27
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Jacovella U, Muller G, Catani KJ, Bartlett NI, Bieske EJ. Electronic Spectra of the Triacetylene Cation (HC6H+) and Protonated Triacetylene (HC6H2+) Tagged with Ar. Aust J Chem 2019. [DOI: 10.1071/ch18508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Polyacetylene cations (HC2nH+) play important roles in combustion processes and in the chemistry of planetary atmospheres and interstellar clouds. Here we report the electronic spectrum for the triacetylene cation (HC6H+) recorded over the 300–610nm range by photodissociating mass-selected ions tagged with argon atoms in a tandem mass spectrometer. The spectrum shows three band systems that are assigned to (origin transition 16665cm−1), (origin transition 23916cm−1), and (origin transition 29920cm−1). Although the band system is well known, the and band systems are observed for the first time in the gas phase. In addition, the electronic spectrum of the protonated triacteylene cation tagged with an argon atom (HC6-Ar) is reported, providing the first gas-phase spectrum for this species.
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28
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Bull JN, Buntine JT, Scholz MS, Carrascosa E, Giacomozzi L, Stockett MH, Bieske EJ. Photodetachment and photoreactions of substituted naphthalene anions in a tandem ion mobility spectrometer. Faraday Discuss 2019; 217:34-46. [DOI: 10.1039/c8fd00217g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Tandem IMS-laser-IMS is used to probe the intrinsic electronic absorptions of deprotonated substituted naphthalene anions.
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29
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Bull JN, Carrascosa E, Giacomozzi L, Bieske EJ, Stockett MH. Ion mobility action spectroscopy of flavin dianions reveals deprotomer-dependent photochemistry. Phys Chem Chem Phys 2018; 20:19672-19681. [PMID: 30014081 PMCID: PMC6063075 DOI: 10.1039/c8cp03244k] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Photo-induced proton transfer, deprotomer-dependent photochemistry, and intramolecular charge transfer in flavin anions are investigated using action spectroscopy.
The intrinsic optical properties and photochemistry of flavin adenine dinucleotide (FAD) dianions are investigated using a combination of tandem ion mobility spectrometry and action spectroscopy. Two principal isomers are observed, the more stable form being deprotonated on the isoalloxazine group and a phosphate (N-3,PO4 deprotomer), and the other on the two phosphates (PO4,PO4 deprotomer). Ion mobility data and electronic action spectra suggest that photo-induced proton transfer occurs from the isoalloxazine group to a phosphate group, converting the PO4,PO4 deprotomer to the N-3,PO4 deprotomer. Comparisons of the isomer selective action spectra of FAD dianions and flavin monoanions with solution spectra and gas-phase photodissociation action spectra suggests that solvation shifts the electronic absorption of the deprotonated isoalloxazine group to higher energy. This is interpreted as evidence for significant charge transfer in the lowest optical transition of deprotonated isoalloxazine. Overall, this work demonstrates that the site of deprotonation of flavin anions strongly affects their electronic absorptions and photochemistry.
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Affiliation(s)
- James N Bull
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Eduardo Carrascosa
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia
| | | | - Evan J Bieske
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Mark H Stockett
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia and Department of Physics, Stockholm University, Stockholm, Sweden.
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30
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Bull JN, Scholz MS, Carrascosa E, da Silva G, Bieske EJ. Double Molecular Photoswitch Driven by Light and Collisions. Phys Rev Lett 2018; 120:223002. [PMID: 29906145 DOI: 10.1103/physrevlett.120.223002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Indexed: 06/08/2023]
Abstract
The shapes of many molecules can be transformed by light or heat. Here we investigate collision- and photon-induced interconversions of EE, EZ, and ZZ isomers of the isolated Congo red (CR) dianion, a double molecular switch containing two ─N═N─ azo groups, each of which can have the E or Z configuration. We find that collisional activation of CR dianions drives a one-way ZZ→EZ→EE cascade towards the lowest-energy isomer, whereas the absorption of a single photon over the 270-600 nm range can switch either azo group from E to Z or Z to E, driving the CR dianion to lower- or higher-energy forms. The experimental results, which are interpreted with the aid of calculated statistical isomerization rates, indicate that photoisomerization of CR in the gas phase involves a passage through conical intersection seams linking the excited and ground state potential energy surfaces rather than through isomerization on the ground state potential energy surface following internal conversion.
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Affiliation(s)
- James N Bull
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Michael S Scholz
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Eduardo Carrascosa
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Gabriel da Silva
- Department of Chemical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Evan J Bieske
- School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
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31
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Carrascosa E, Bull JN, Scholz MS, Coughlan NJA, Olsen S, Wille U, Bieske EJ. Reversible Photoisomerization of the Isolated Green Fluorescent Protein Chromophore. J Phys Chem Lett 2018; 9:2647-2651. [PMID: 29724104 DOI: 10.1021/acs.jpclett.8b01201] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Fluorescent proteins have revolutionized the visualization of biological processes, prompting efforts to understand and control their intrinsic photophysics. Here we investigate the photoisomerization of deprotonated p-hydroxybenzylidene-2,3-dimethylimidazolinone anion (HBDI-), the chromophore in green fluorescent protein and in Dronpa protein, where it plays a role in switching between fluorescent and nonfluorescent states. In the present work, isolated HBDI- molecules are switched between the Z and E forms in the gas phase in a tandem ion mobility mass spectrometer outfitted for selecting the initial and final isomers. Excitation of the S1 ← S0 transition provokes both Z → E and E → Z photoisomerization, with a maximum response for both processes at 480 nm. Photodetachment is a minor channel at low light intensity. At higher light intensities, absorption of several photons in the drift region drives photofragmentation, through channels involving CH3 loss and concerted CO and CH3CN loss, although isomerization remains the dominant process.
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Affiliation(s)
- Eduardo Carrascosa
- School of Chemistry , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - James N Bull
- School of Chemistry , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Michael S Scholz
- School of Chemistry , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Neville J A Coughlan
- School of Chemistry , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Seth Olsen
- School of Chemistry , Monash University , Clayton , Victoria 3800 , Australia
| | - Uta Wille
- School of Chemistry , The University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Evan J Bieske
- School of Chemistry , The University of Melbourne , Parkville , Victoria 3010 , Australia
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32
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Scholz MS, Bull JN, Carrascosa E, Adamson BD, Kosgei GK, Rack JJ, Bieske EJ. Linkage Photoisomerization of an Isolated Ruthenium Sulfoxide Complex: Sequential versus Concerted Rearrangement. Inorg Chem 2018; 57:5701-5706. [PMID: 29663799 DOI: 10.1021/acs.inorgchem.8b00871] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ruthenium sulfoxide complexes undergo thermally reversible linkage isomerization of sulfoxide ligands from S- to O-bound in response to light. Here, we report photoisomerization action spectra for a ruthenium bis-sulfoxide molecular photoswitch, [Ru(bpy)2(bpSO)]2+, providing the first direct evidence for photoisomerization of a transition metal complex in the gas phase. The linkage isomers are separated and isolated in a tandem drift tube ion mobility spectrometer and exposed to tunable laser radiation provoking photoisomerization. Direct switching of the S,S-isomer to the O,O-isomer following absorption of a single photon is the predominant isomerization pathway in the gas phase, unlike in solution, where stepwise isomerization is observed with each sulfoxide ligand switching in turn. The change in isomerization dynamics is attributed to rapid vibrational quenching that suppresses isomerization in solution. Supporting electronic structure calculations predict the wavelengths and intensities of the peaks in the photoisomerization action spectra of the S,S- and S,O-isomers, indicating that they correspond to metal-to-ligand charge transfer (MLCT) and ligand-centered ππ* transitions.
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Affiliation(s)
- Michael S Scholz
- School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | - James N Bull
- School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Eduardo Carrascosa
- School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Brian D Adamson
- School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia.,Sandia National Laboratories, Livermore , California 94550 , United States
| | - Gilbert K Kosgei
- Department of Chemistry and Chemical Biology , University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - Jeffrey J Rack
- Department of Chemistry and Chemical Biology , University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - Evan J Bieske
- School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
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33
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Poad BLJ, Maccarone AT, Yu H, Mitchell TW, Saied EM, Arenz C, Hornemann T, Bull JN, Bieske EJ, Blanksby SJ. Differential-Mobility Spectrometry of 1-Deoxysphingosine Isomers: New Insights into the Gas Phase Structures of Ionized Lipids. Anal Chem 2018; 90:5343-5351. [PMID: 29608293 DOI: 10.1021/acs.analchem.8b00469] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Separation and structural identification of lipids remain a major challenge for contemporary lipidomics. Regioisomeric lipids differing only in position(s) of unsaturation are often not differentiated by conventional liquid chromatography-mass spectrometry approaches leading to the incomplete, or sometimes incorrect, assignation of molecular structure. Here we describe an investigation of the gas phase separations by differential-mobility spectrometry (DMS) of a series of synthetic analogues of the recently described 1-deoxysphingosine. The dependence of the DMS behavior on the position of the carbon-carbon double bond within the ionized lipid is systematically explored and compared to trends from complementary investigations, including collision cross-sections measured by drift tube ion mobility, reaction efficiency with ozone, and molecular dynamics simulations. Consistent trends across these modes of interrogation point to the importance of direct, through-space interactions between the charge site and the carbon-carbon double bond. Differences in the geometry and energetics of this intramolecular interaction underpin DMS separations and influence reactivity trends between regioisomers. Importantly, the disruption and reformation of these intramolecular solvation interactions during DMS are proposed to be the causative factor in the observed separations of ionized lipids which are shown to have otherwise identical collision cross-sections. These findings provide key insights into the strengths and limitations of current ion-mobility technologies for lipid isomer separations and can thus guide a more systematic approach to improved analytical separations in lipidomics.
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Affiliation(s)
- Berwyck L J Poad
- Central Analytical Research Facility, Institute for Future Environments , Queensland University of Technology , Brisbane , Queensland 4001 , Australia
| | - Alan T Maccarone
- Mass Spectrometry User Resource and Research Facility , University of Wollongong , Wollongong , New South Wales 2522 , Australia.,School of Chemistry , University of Wollongong , Wollongong , New South Wales 2522 , Australia
| | - Haibo Yu
- School of Chemistry , University of Wollongong , Wollongong , New South Wales 2522 , Australia
| | - Todd W Mitchell
- School of Medicine , University of Wollongong , Wollongong , New South Wales 2522 , Australia
| | - Essa M Saied
- Institute for Chemistry , Humboldt Universität zu Berlin , 12489 Berlin , Germany.,Chemistry Department, Faculty of Science , Suez Canal University , 41522 Ismailia , Egypt
| | - Christoph Arenz
- Institute for Chemistry , Humboldt Universität zu Berlin , 12489 Berlin , Germany
| | - Thorsten Hornemann
- Institute of Clinical Chemistry , University Hospital of Zurich , CH-8091 Zurich , Switzerland
| | - James N Bull
- School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Evan J Bieske
- School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Stephen J Blanksby
- Central Analytical Research Facility, Institute for Future Environments , Queensland University of Technology , Brisbane , Queensland 4001 , Australia
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Abstract
Donor-acceptor Stenhouse adducts (DASAs) are a new class of photoswitching molecules with excellent fatigue resistance and synthetic tunability. Here, tandem ion mobility mass spectrometry coupled with laser excitation is used to characterize the photocyclization reaction of isolated, charge-tagged DASA molecules over the 450-580 nm range. The experimental maximum response at 530 nm agrees with multireference perturbation theory calculations for the S1 ← S0 transition maximum at 533 nm. Photocyclization in the gas phase involves absorption of at least two photons; the first photon induces Z-E isomerization from the linear isomer to metastable intermediate isomers, while the second photon drives another E-Z isomerization and 4π-electrocyclization reaction. Cyclization is thermally reversible in the gas phase with collisional excitation.
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Affiliation(s)
- James N Bull
- School of Chemistry, University of Melbourne , Parkville, Victoria 3010, Australia
| | - Eduardo Carrascosa
- School of Chemistry, University of Melbourne , Parkville, Victoria 3010, Australia
| | - Neil Mallo
- School of Chemistry, UNSW Sydney , High Street, Kensington, New South Wales 2052, Australia
| | - Michael S Scholz
- School of Chemistry, University of Melbourne , Parkville, Victoria 3010, Australia
| | - Gabriel da Silva
- Department of Chemical Engineering, University of Melbourne , Parkville, Victoria 3010, Australia
| | - Jonathon E Beves
- School of Chemistry, UNSW Sydney , High Street, Kensington, New South Wales 2052, Australia
| | - Evan J Bieske
- School of Chemistry, University of Melbourne , Parkville, Victoria 3010, Australia
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35
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Bull JN, Scholz MS, Carrascosa E, Bieske EJ. FromEtoZand back again: reversible photoisomerisation of an isolated charge-tagged azobenzene. Phys Chem Chem Phys 2018; 20:509-513. [DOI: 10.1039/c7cp07278c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Substituted azobenzenes serve as chromophores and actuators in a wide range of molecular photoswitches.
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Affiliation(s)
- James N. Bull
- School of Chemistry
- University of Melbourne
- Parkville
- Australia
| | | | | | - Evan J. Bieske
- School of Chemistry
- University of Melbourne
- Parkville
- Australia
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36
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Catani KJ, Muller G, Jusko P, Theulé P, Bieske EJ, Jouvet C. Electronic spectrum of the protonated diacetylene cation (H2C4H+). J Chem Phys 2017; 147:084302. [DOI: 10.1063/1.4990572] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Giel Muller
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Pavol Jusko
- Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
- CNRS, Aix Marseille Université, Physique des Interactions Ioniques et Moléculaires (PIIM) UMR 7345, 13397 Marseille Cedex, France
| | - Patrice Theulé
- CNRS, Aix Marseille Université, Physique des Interactions Ioniques et Moléculaires (PIIM) UMR 7345, 13397 Marseille Cedex, France
| | - Evan J. Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Christophe Jouvet
- CNRS, Aix Marseille Université, Physique des Interactions Ioniques et Moléculaires (PIIM) UMR 7345, 13397 Marseille Cedex, France
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Scholz MS, Bull JN, Coughlan NJA, Carrascosa E, Adamson BD, Bieske EJ. Photoisomerization of Protonated Azobenzenes in the Gas Phase. J Phys Chem A 2017; 121:6413-6419. [DOI: 10.1021/acs.jpca.7b05902] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
| | - James N. Bull
- School
of Chemistry, University of Melbourne, Melbourne, Australia
| | - Neville J. A. Coughlan
- School
of Chemistry, University of Melbourne, Melbourne, Australia
- Department
of Chemistry, University of Oxford, Oxford, United Kingdom
| | | | - Brian D. Adamson
- School
of Chemistry, University of Melbourne, Melbourne, Australia
- Sandia National Laboratories, Livermore, California 94551, United States
| | - Evan J. Bieske
- School
of Chemistry, University of Melbourne, Melbourne, Australia
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38
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Affiliation(s)
- James N. Bull
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
| | | | - Evan J. Bieske
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
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39
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Ritchie C, Vamvounis G, Soleimaninejad H, Smith TA, Bieske EJ, Dryza V. Photochrome-doped organic films for photonic keypad locks and multi-state fluorescence. Phys Chem Chem Phys 2017; 19:19984-19991. [PMID: 28722049 DOI: 10.1039/c7cp02818k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The spectroscopic properties of poly(methyl methacrylate) polymer films doped with two kinds of photochromic molecular switches are investigated. A green-fluorescent sulfonyl diarylethene (P1) is combined with either a non-fluorescent diarylethene (P2) or red-fluorescent spiropyran (P3). Photoswitching between the colorless and colored isomers (P1: o-BTFO4 ↔ c-BTFO4, P2: o-DTE ↔ c-DTE, P3: SP ↔ MC) enables the P1 + P2 and P1 + P3 films to be cycled through three distinct states. From the initial state (o-BTFO4 + o-DTE/SP), irradiation with UV light generates the second state (c-BTFO4 + c-DTE/MC), where c-BTFO4 → c-DTE/MC energy transfer is established. Irradiation with green light then generates the third state (c-BTFO4 + o-DTE/SP), where the energy transfer acceptor is no longer present. Finally, irradiation with blue light regenerates the initial state. For the P1 + P2 film, only one state is fluorescent, with the irradiation inputs required to be entered in the correct order to access this state, acting as a keypad lock. For the P1 + P3 film, the states emit either no fluorescence, red fluorescence, or green fluorescence, all using a common excitation wavelength. Additionally, once the fluorescence is activated with UV light, it undergoes a time-dependent color transition from red to green, due to the pairing of P-type and T-type photochromes. These multi-photochromic systems may be useful for security ink or imaging applications.
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Affiliation(s)
- Chris Ritchie
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia.
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40
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Georgiou DC, Haghighatbin MA, Hogan CF, Scholz MS, Bull JN, Bieske EJ, Wilson DJD, Dutton JL. A Strong
cis
‐Effect in an Imidazole‐Imidazolium‐Substituted Alkene. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201702287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Dayne C. Georgiou
- Department of Chemistry and Physics La Trobe Institute for Molecular Science La Trobe University Melbourne Victoria 3086 Australia
| | - Mohammad A. Haghighatbin
- Department of Chemistry and Physics La Trobe Institute for Molecular Science La Trobe University Melbourne Victoria 3086 Australia
| | - Conor F. Hogan
- Department of Chemistry and Physics La Trobe Institute for Molecular Science La Trobe University Melbourne Victoria 3086 Australia
| | - Michael S. Scholz
- School of Chemistry University of Melbourne Parkville Victoria 3010 Australia
| | - James N. Bull
- School of Chemistry University of Melbourne Parkville Victoria 3010 Australia
| | - Evan J. Bieske
- School of Chemistry University of Melbourne Parkville Victoria 3010 Australia
| | - David J. D. Wilson
- Department of Chemistry and Physics La Trobe Institute for Molecular Science La Trobe University Melbourne Victoria 3086 Australia
| | - Jason L. Dutton
- Department of Chemistry and Physics La Trobe Institute for Molecular Science La Trobe University Melbourne Victoria 3086 Australia
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Lim SF, Harris BL, Khairallah GN, Bieske EJ, Maître P, da Silva G, Adamson BD, Scholz MS, Coughlan NJA, O'Hair RAJ, Rathjen M, Stares D, White JM. Seleniranium Ions Undergo π-Ligand Exchange via an Associative Mechanism in the Gas Phase. J Org Chem 2017; 82:6289-6297. [PMID: 28530810 DOI: 10.1021/acs.joc.7b00877] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Collision-induced dissociation mass spectrometry of the ammonium ions 4a and 4b results in the formation of the seleniranium ion 5, the structure and purity of which were verified using gas-phase infrared spectroscopy coupled to mass spectrometry and gas-phase ion-mobility measurements. Ion-molecule reactions between the ion 5 (m/z = 261) and cyclopentene, cyclohexene, cycloheptene, and cyclooctene resulted in the formation of the seleniranium ions 7 (m/z = 225), 6 (m/z = 239), 8 (m/z = 253), and 9 (m/z = 267), respectively. Further reaction of seleniranium 6 with cyclopentene resulted in further π-ligand exchange giving seleniranium ion 7, confirming that direct π-ligand exchange between seleniranium ion 5 and cycloalkenes occurs in the gas phase. Pseudo-first-order kinetics established relative reaction efficiencies for π-ligand exchange for cyclopentene, cyclohexene, cycloheptene. and cyclooctene as 0.20, 0.07, 0.43, and 4.32. respectively. DFT calculations at the M06/6-31+G(d) level of theory provide the following insights into the mechanism of the π-ligand exchange reactions; the cycloalkene forms a complex with the seleniranium ion 5 with binding energies of 57 and 62 kJ/mol for cyclopentene and cyclohexene, respectively, with transition states for π-ligand exchange having barriers of 17.8 and 19.3 kJ/mol for cyclopentene and cyclohexene, respectively.
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Affiliation(s)
- S Fern Lim
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Benjamin L Harris
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - George N Khairallah
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia.,Accurate Mass Scientific Pty Ltd., P.O. Box 92, Keilor, VIC 3036, Australia
| | - E J Bieske
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Philippe Maître
- Laboratoire de Chimie Physique, Université Paris-Sud, CNRS, Université Paris-Saclay , F-91405 Orsay, France
| | - Gabriel da Silva
- Chemical and Biomolecular Engineering, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Brian D Adamson
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Michael S Scholz
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Neville J A Coughlan
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Richard A J O'Hair
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Michael Rathjen
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Daniel Stares
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
| | - Jonathan M White
- School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Melbourne 3010, Australia
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42
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Georgiou DC, Haghighatbin MA, Hogan CF, Scholz MS, Bull JN, Bieske EJ, Wilson DJD, Dutton JL. A Strong
cis
‐Effect in an Imidazole‐Imidazolium‐Substituted Alkene. Angew Chem Int Ed Engl 2017; 56:8473-8480. [DOI: 10.1002/anie.201702287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Dayne C. Georgiou
- Department of Chemistry and Physics La Trobe Institute for Molecular Science La Trobe University Melbourne Victoria 3086 Australia
| | - Mohammad A. Haghighatbin
- Department of Chemistry and Physics La Trobe Institute for Molecular Science La Trobe University Melbourne Victoria 3086 Australia
| | - Conor F. Hogan
- Department of Chemistry and Physics La Trobe Institute for Molecular Science La Trobe University Melbourne Victoria 3086 Australia
| | - Michael S. Scholz
- School of Chemistry University of Melbourne Parkville Victoria 3010 Australia
| | - James N. Bull
- School of Chemistry University of Melbourne Parkville Victoria 3010 Australia
| | - Evan J. Bieske
- School of Chemistry University of Melbourne Parkville Victoria 3010 Australia
| | - David J. D. Wilson
- Department of Chemistry and Physics La Trobe Institute for Molecular Science La Trobe University Melbourne Victoria 3086 Australia
| | - Jason L. Dutton
- Department of Chemistry and Physics La Trobe Institute for Molecular Science La Trobe University Melbourne Victoria 3086 Australia
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43
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O'Connor GD, Chan B, Sanelli JA, Cergol KM, Dryza V, Payne RJ, Bieske EJ, Radom L, Schmidt TW. Hydrogen-adduction to open-shell graphene fragments: spectroscopy, thermochemistry and astrochemistry. Chem Sci 2017; 8:1186-1194. [PMID: 28451259 PMCID: PMC5369534 DOI: 10.1039/c6sc03787a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 09/24/2016] [Indexed: 11/25/2022] Open
Abstract
We apply a combination of state-of-the-art experimental and quantum-chemical methods to elucidate the electronic and chemical energetics of hydrogen adduction to a model open-shell graphene fragment. The lowest-energy adduct, 1H-phenalene, is determined to have a bond dissociation energy of 258.1 kJ mol-1, while other isomers exhibit reduced or in some cases negative bond dissociation energies, the metastable species being bound by the emergence of a conical intersection along the high-symmetry dissociation coordinate. The gas-phase excitation spectrum of 1H-phenalene and its radical cation are recorded using laser spectroscopy coupled to mass-spectrometry. Several electronically excited states of both species are observed, allowing the determination of the excited-state bond dissociation energy. The ionization energy of 1H-phenalene is determined to be 7.449(17) eV, consistent with high-level W1X-2 calculations.
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Affiliation(s)
- Gerard D O'Connor
- School of Chemistry , UNSW Sydney , NSW 2052 , Australia . ; Tel: +61 439 386 109
| | - Bun Chan
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
- Graduate School of Engineering , Nagasaki University , Bunkyo 1-14 , Nagasaki 852-8521 , Japan
| | - Julian A Sanelli
- School of Chemistry , The University of Melbourne , Victoria 3010 , Australia
| | - Katie M Cergol
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Viktoras Dryza
- School of Chemistry , The University of Melbourne , Victoria 3010 , Australia
| | - Richard J Payne
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Evan J Bieske
- School of Chemistry , The University of Melbourne , Victoria 3010 , Australia
| | - Leo Radom
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Timothy W Schmidt
- School of Chemistry , UNSW Sydney , NSW 2052 , Australia . ; Tel: +61 439 386 109
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Catani KJ, Muller G, da Silva G, Bieske EJ. Electronic spectrum and photodissociation chemistry of the linear methyl propargyl cation H2C4H3+. J Chem Phys 2017; 146:044307. [DOI: 10.1063/1.4974338] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Giel Muller
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Gabriel da Silva
- Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010, Australia
| | - Evan J. Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
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Bull JN, Carrascosa E, Scholz MS, Coughlan NJA, Bieske EJ. Online measurement of photoisomerisation efficiency in solution using ion mobility mass spectrometry. Analyst 2017; 142:2100-2103. [DOI: 10.1039/c7an00398f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A new method for probing the photoisomerisation of molecules in solution using ion mobility mass spectrometry is described and demonstrated with a azoheteroarene photoswitch.
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Affiliation(s)
- James N. Bull
- School of Chemistry
- University of Melbourne
- Melbourne
- Australia
| | | | | | | | - Evan J. Bieske
- School of Chemistry
- University of Melbourne
- Melbourne
- Australia
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46
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Bull JN, Scholz MS, Coughlan NJA, Bieske EJ. Isomerisation of an intramolecular hydrogen-bonded photoswitch: protonated azobis(2-imidazole). Phys Chem Chem Phys 2017; 19:12776-12783. [DOI: 10.1039/c7cp01733b] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Reversible E–Z photoswitching of a protonated azoheteroarene is demonstrated using ion mobility mass spectrometry.
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Affiliation(s)
- James N. Bull
- School of Chemistry
- University of Melbourne
- Parkville
- Australia
| | | | | | - Evan J. Bieske
- School of Chemistry
- University of Melbourne
- Parkville
- Australia
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47
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Bull JN, Scholz MS, Coughlan NJA, Kawai A, Bieske EJ. Monitoring Isomerization of Molecules in Solution Using Ion Mobility Mass Spectrometry. Anal Chem 2016; 88:11978-11981. [DOI: 10.1021/acs.analchem.6b04000] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James N. Bull
- School
of Chemistry, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Michael S. Scholz
- School
of Chemistry, University of Melbourne, Melbourne, Victoria 3010, Australia
| | | | - Akio Kawai
- Department
of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, Ohokayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Evan J. Bieske
- School
of Chemistry, University of Melbourne, Melbourne, Victoria 3010, Australia
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48
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Coughlan NJA, Scholz MS, Hansen CS, Trevitt AJ, Adamson BD, Bieske EJ. Photo and Collision Induced Isomerization of a Cyclic Retinal Derivative: An Ion Mobility Study. J Am Soc Mass Spectrom 2016; 27:1483-1490. [PMID: 27278825 DOI: 10.1007/s13361-016-1427-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/10/2016] [Accepted: 05/20/2016] [Indexed: 06/06/2023]
Abstract
A cationic degradation product, formed in solution from retinal Schiff base (RSB), is examined in the gas phase using ion mobility spectrometry, photoisomerization action spectroscopy, and collision induced dissociation (CID). The degradation product is found to be N-n-butyl-2-(β-ionylidene)-4-methylpyridinium (BIP) produced through 6π electrocyclization of RSB followed by protonation and loss of dihydrogen. Ion mobility measurements show that BIP exists as trans and cis isomers that can be interconverted through buffer gas collisions and by exposure to light, with a maximum response at λ = 420 nm.Graphical Abstract.
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Affiliation(s)
| | - Michael S Scholz
- School of Chemistry, University of Melbourne, Melbourne, Australia
| | | | - Adam J Trevitt
- School of Chemistry, University of Wollongong, Wollongong, Australia
| | - Brian D Adamson
- School of Chemistry, University of Melbourne, Melbourne, Australia
| | - Evan J Bieske
- School of Chemistry, University of Melbourne, Melbourne, Australia.
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49
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Abstract
The photoisomerization of β-ionone protonated Schiff base (BIPSB) is investigated in the gas phase by irradiating mobility-selected ions in a tandem ion mobility spectrometer with tunable radiation. Four distinguishable isomers are produced by electrospray ionization whose structures are deduced from their collision cross sections and photoisomerization behavior along with density functional theory calculations. They include two geometric isomers of BIPSB with trans or cis configurations about the polyene chain's terminal C═N double bond, a bicyclic structure formed through electrocyclization of the polyene chain, and a Z-retro-γ-ionone isomer. Although trans-BIPSB and 9-cis-BIPSB have similar photoisomerization action spectra, with a maximum response at 375 nm, they photoconvert to different isomers. The trans-BIPSB isomer transforms to the bicyclic form upon exposure to light over the 320-400 nm range, whereas the cis-BIPSB isomer is prevented by steric hindrance from forming the bicyclic BIPSB isomer following irradiation and is proposed instead to form the 7,9-di-cis isomer. Neither the bicyclic isomer nor the Z-retro-γ-ionone isomer respond strongly to near-UV light.
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Affiliation(s)
| | - Claire M Wallace
- School of Chemistry, The University of Melbourne , Victoria 3010, Australia
| | - Brian D Adamson
- School of Chemistry, The University of Melbourne , Victoria 3010, Australia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne , Victoria 3010, Australia
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50
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Artiukhin DG, Bieske EJ, Buchachenko AA. Ab Initio Characterization of the Electrostatic Complexes Formed by H2 Molecule and Cr(+), Mn(+), Cu(+), and Zn(+) Cations. J Phys Chem A 2016; 120:5006-15. [PMID: 26914616 DOI: 10.1021/acs.jpca.5b12700] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Equilibrium structures, dissociation energies, and rovibrational energy levels of the electrostatic complexes formed by molecular hydrogen and first-row S-state transition metal cations Cr(+), Mn(+), Cu(+), and Zn(+) are investigated ab initio. Extensive testing of the CCSD(T)-based approaches for equilibrium structures provides an optimal scheme for the potential energy surface calculations. These surfaces are calculated in two dimensions by keeping the H-H internuclear distance fixed at its equilibrium value in the complex. Subsequent variational calculations of the rovibrational energy levels permits direct comparison with data obtained from equilibrium thermochemical and spectroscopic measurements. Overall accuracy within 2-3% is achieved. Theoretical results are used to examine trends in hydrogen activation, vibrational anharmonicity, and rotational structure along the sequence of four electrostatic complexes covering the range from a relatively floppy van der Waals system (Mn(+)···H2) to an almost a rigid molecular ion (Cu(+)···H2).
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Affiliation(s)
- Denis G Artiukhin
- Department of Chemistry, Moscow State University , Moscow 119991, Russia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne , Parkville, VIC 3010, Australia
| | - Alexei A Buchachenko
- Skolkovo Institute of Science and Technology , 100 Novaya Street, Skolkovo, Odintsovsky District, Moscow Region 143025, Russia
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