Two-laser multiphoton dissociation of iodobenzene cation

Dunbar, Robert C.; Hays, John D.; Honovich, Jeffrey P.; Lev, Naomi B.

doi:10.1021/ja00531a046

Cited by 20 publications

(5 citation statements)

References 4 publications

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“…15 We began this portion of our investigation using norbornene and β-pinene, because these strained alkenes are known to be more reactive than cyclohexene. 16 Utilizing our originally optimized conditions, the ATRA of CCl 3 Br to norbornene was sluggish, partly attributable to the low solubility of norbornene in DMF/H 2 O. However, the newly optimized conditions utilizing DMSO and 2 provided a homogeneous reaction mixture and the atom transfer addition product in high yield (Scheme 2).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…In addition, we failed to couple CCl 4 to any of the olefins (eq ), even though the excited state reduction potential of 1 (Ir 4+ /Ir 3+* = −0.89 V vs SCE) should be sufficient to reduce CCl 4 (−0.78 V vs SCE) . We began this portion of our investigation using norbornene and β-pinene, because these strained alkenes are known to be more reactive than cyclohexene …”

Section: Resultsmentioning

confidence: 99%

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Visible Light-Mediated Atom Transfer Radical Addition via Oxidative and Reductive Quenching of Photocatalysts

et al. 2012

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Herein, the development of visible light-mediated atom transfer radical addition (ATRA) of haloalkanes onto alkenes and alkynes using the reductive and oxidative quenching of [Ir{dF(CF(3))ppy}(2)(dtbbpy)]PF(6) and [Ru(bpy)(3)]Cl(2) is presented. Initial investigations indicated that the oxidative quenching of photocatalysts could effectively be utilized for ATRA, and since that report, the protocol has been expanded by broadening the scope of the reaction in terms of the photocatalysts, substrates, and solvents. In addition, further modifications of the reaction conditions allowed for the efficient ATRA of perfluoroalkyl iodides onto alkenes and alkynes utilizing the reductive quenching cycle of [Ru(bpy)(3)]Cl(2) with sodium ascorbate as the sacrificial electron donor. These results signify the complementary nature of the oxidative and reductive quenching pathways of photocatalysts and the ability to predictably direct reaction outcome through modification of the reaction conditions.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Visible Light-Mediated Atom Transfer Radical Addition via Oxidative and Reductive Quenching of Photocatalysts

et al. 2012

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“…Photodissociation of large biomolecular ions is often in competition with other energy relaxation processes, which reduce the photodissociation yields. This limitation can be overcome by additional excitation of the ions by multiple IR photons 15 . The power of the IR laser (typically CO 2 ) is chosen such that no dissociation occurs in the absence of the UV/Vis excitation.…”

Section: Classification Of the Gas‐phase Photodissociation Ion Spectr...mentioning

confidence: 99%

“…This limitation can be overcome by additional excitation of the ions by multiple IR photons. 15 The power of the IR laser (typically CO 2 ) is chosen such that no dissociation occurs in the absence of the UV/Vis excitation. Additional energy from the absorbed IR photons significantly increases the dissociation yield.…”

Section: Classification Of the Gas‐phase Photodissociation Ion Spectr...mentioning

confidence: 99%

Experimental techniques and terminology in gas‐phase ion spectroscopy

Pereverzev¹,

Roithová²

2022

J Mass Spectrom

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This perspective gives an overview of the action spectroscopy methods for measurements of electronic, vibrational, and rotational spectra of mass‐selected ions in the gas phase. We classify and give a short overview of the existing experimental approaches in this field. There is currently a plethora of names used for, essentially, the same techniques. Hence within this overview, we scrutinized the notations and suggested terms to be generally used. The selection was either driven by making the name unique and straightforward or the term being the most broadly used one. We believe that a simplification and a unification of the notation in ion spectroscopy can make this field better accessible for experts outside the mass spectrometry community where the applications of gas‐phase action ion spectroscopy can make a large impact.

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“…In work coupling a CO 2 laser and his dye laser for irradiation of the iodobenzene cation, his group found that a balance was rapidly established between IR excitation and relaxation, allowing the ion to remain in a reasonably narrow internal energy range, from which single-photon photodissociation produced by the visible laser could proceed. 7 Rob used this two-laser approach to obtain radiative relaxation lifetimes of iodo- and bromobenzene cations 8 and for limited vibrational spectroscopy (over the 9.7–10.7 µm tunability range of the CO 2 laser) of the two halobenzene cations and m -iodotoluene. 9 With an approach similar to that employed earlier 6 with bromobenzene he was able to determine the rates of both collisional and infrared fluorescence relaxation of the one-photon excited ions, 10 finding that the IR fluorescence proceeded with a characteristic relaxation time of about 0.5 s.…”

Section: Introductionmentioning

confidence: 99%

Gas-phase metal ion chelation investigated with IRMPD spectroscopy: A brief review of Robert Dunbar’s contributions

Polfer

Berden

Eyler

2018

Eur J Mass Spectrom (Chichester)

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With the passing of Prof. Robert C. Dunbar on 31 October 2017, the field of ion chemistry lost one of its modern heroes. Throughout his career in mass spectrometry, two of his main research interests involved the interaction of trapped ions with electromagnetic radiation and the chelation motifs of metal ions with organic ligands. The focus of his early career was on the fundamental processes that take place in molecules upon ultraviolet and infrared excitation. From 2003 to 2017, his scientific interests shifted to more structural questions, notably to resolving the structures and binding motifs of metal ion chelation complexes by application of infrared photodissociation spectroscopy. These experiments were carried out during numerous visits to the (Free Electron Laser for Infrared eXperiments) (FELIX) facility in the Netherlands and were complemented by extensive theoretical investigations by Rob. As a tribute to our friend, we present in this contribution a brief review of this work.

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Two-laser multiphoton dissociation of iodobenzene cation

Cited by 20 publications

References 4 publications

Visible Light-Mediated Atom Transfer Radical Addition via Oxidative and Reductive Quenching of Photocatalysts

Visible Light-Mediated Atom Transfer Radical Addition via Oxidative and Reductive Quenching of Photocatalysts

Experimental techniques and terminology in gas‐phase ion spectroscopy

Gas-phase metal ion chelation investigated with IRMPD spectroscopy: A brief review of Robert Dunbar’s contributions

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