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Tureček F. UV-vis spectroscopy of gas-phase ions. MASS SPECTROMETRY REVIEWS 2023; 42:206-226. [PMID: 34392556 DOI: 10.1002/mas.21726] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 06/13/2023]
Abstract
Photodissociation action spectroscopy has made a great progress in expanding investigations of gas-phase ion structures. This review deals with aspects of gas-phase ion electronic excitations that result in wavelength-dependent dissociation and light emission via fluorescence, chiefly covering the ultraviolet and visible regions of the spectrum. The principles are briefly outlined and a few examples of instrumentation are presented. The main thrust of the review is to collect and selectively present applications of UV-vis action spectroscopy to studies of stable gas-phase ion structures and combinations of spectroscopy with ion mobility, collision-induced dissociation, and ion-ion reactions leading to the generation of reactive intermediates and electronic energy transfer.
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Affiliation(s)
- František Tureček
- Department of Chemistry, University of Washington, Seattle, Washington, USA
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2
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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. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 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] [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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3
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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: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [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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4
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Evaluation of ultraviolet photodissociation tandem mass spectrometry for the structural assignment of unsaturated fatty acid double bond positional isomers. Anal Bioanal Chem 2020; 412:2339-2351. [PMID: 32006064 DOI: 10.1007/s00216-020-02446-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/18/2019] [Accepted: 01/21/2020] [Indexed: 12/13/2022]
Abstract
Fatty acids are a major source of structural diversity within the lipidome due to variations in their acyl chain lengths, branching, and cyclization, as well as the number, position, and stereochemistry of double bonds within their mono- and poly-unsaturated species. Here, the utility of 193 nm UltraViolet PhotoDissociation tandem mass spectrometry (UVPD-MS/MS) has been evaluated for the detailed structural characterization of a series of unsaturated fatty acid lipid species. UVPD-MS/MS of unsaturated fatty acids is shown to yield pairs of unique diagnostic product ions resulting from cleavages adjacent to their C=C double bonds, enabling unambiguous localization of the site(s) of unsaturation within these lipids. The effect of several experimental variables on the observed fragmentation behaviour and UVPD-MS/MS efficiency, including the position and number of double bonds, the effect of conjugated versus non-conjugated double bonds, the number of laser pulses, and the influence of alkali metal cations (Li, Na, K) as the ionizing adducts, has been evaluated. Importantly, the abundance of the diagnostic ions is shown to enable relative quantitation of mixtures of fatty acid isomers across a range of molar ratios. Finally, the practical application of 193 nm UVPD-MS/MS is demonstrated via characterization of changes in the ratios of fatty acid double bond positional isomers in isogenic colorectal cancer cell lines. This study therefore demonstrates the practicality of UVPD-MS/MS for the structural characterization of fatty acid isomers in lipidome analysis workflows.
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5
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Litinas I, Koutselos AD. Structure Distribution of Gaseous Ions in Strong Electrostatic Fields. J Phys Chem A 2019; 123:5683-5691. [PMID: 31250648 DOI: 10.1021/acs.jpca.9b03441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In drift tube experiments, where ions move in gases under the action of an electrostatic field, collision excitation is implemented for the study of the energy partitioning in the molecular degrees of freedom and the corresponding relaxation rates when the excitation is turned off. In the case of flexible ions, the vibration modes related to metastable molecular structures have been activated in ion mobility spectrometry and their population has been probed with respect to the field strength and the gas temperature. Here, we study the angular vibrational excitation and relaxation of such systems by examining the motion of molecular ions with one bending mode at strong fields using a nonequilibrium molecular dynamics simulation method. The relatively stable structures are introduced through the use of an intramolecular angular potential with minima at the position of the most stable conformations. We calculate the first few moments of the velocity and angular velocity distribution functions as well as the distribution of the conformers, and find that they follow unified curves when plotted with respect to the relative ion-atom collision energy. At high field strengths, the angular vibration is excited and a portion of the ions interchanges conformations continuously in time with the populations of the molecular structures to attain limiting values. In addition, orientational alignment, with the perpendicular angular momentum being greater than the one parallel to the field, is observed. Our observations, although based on a specific system, must be rather general for the case of large flexible molecular ions.
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Affiliation(s)
- Iraklis Litinas
- Department of Chemistry, Physical Chemistry Laboratory , National and Kapodistrian University of Athens , Panepistimiopolis, 15771 Athens , Greece
| | - Andreas D Koutselos
- Department of Chemistry, Physical Chemistry Laboratory , National and Kapodistrian University of Athens , Panepistimiopolis, 15771 Athens , Greece
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6
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Bull JN, Scholz MS, Carrascosa E, da Silva G, Bieske EJ. Double Molecular Photoswitch Driven by Light and Collisions. PHYSICAL REVIEW LETTERS 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] [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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7
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Bull JN, Carrascosa E, Mallo N, Scholz MS, da Silva G, Beves JE, Bieske EJ. Photoswitching an Isolated Donor-Acceptor Stenhouse Adduct. J Phys Chem Lett 2018; 9:665-671. [PMID: 29356541 DOI: 10.1021/acs.jpclett.7b03402] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
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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8
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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] [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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9
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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] [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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10
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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] [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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