Visible and Ultraviolet Spectroscopy of Gas Phase Rhodamine 575 Cations

Daly, Steven; Kulesza, Alexander; Knight, Geoffrey; MacAleese, Luke; Antoine, Rodolphe; Dugourd, Philippe

doi:10.1021/acs.jpca.5b03187

Cited by 17 publications

(33 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is not possible to perform the same circular dichroism measurements for tagged ubiquitin since both chromophores possess intense ultraviolet absorption features [31] and, hence, it is difficult to obtain direct information on changes in the solution structure following chromophore tagging. It may be noted that the successful use of similar chromophores in solution-phase FRET experiments indicates that such effect must be limited if any useful information is to be derived at all.…”

Section: Resultsmentioning

confidence: 99%

“…In addition, peaks at m/z 414 and 373 (blue circles in Figure 4) observed in Figure 4b can be assigned as internal fragmentation of the donor chromophore [12]. Since fragmentation of the donor has been shown to proceed via higher lying singlet states, this may be indicative of absorption of two photons by the donor due to high laser fluence used [31]. Finally, a multiple charged peak is observed at m/z 1137, and the profile of which indicates it is multiply charged.…”

Section: Resultsmentioning

confidence: 99%

“…The action-spectroscopy experimental setup has been described in detail previously [31], and a brief description is given here. A dual linear ion trap mass spectrometer (LTQ Velos, Thermo Fisher Scientific, San Jose, CA, USA) was modified by positioning a fused silica window (3 mm thick, 1 inch diameter) at the back end of the instrument, and 1–2 mm diameter circular openings in the trapping electrodes to allow coupling of light source and trapped ions.…”

Section: Methodsmentioning

confidence: 99%

“…A detailed description of the action-FRET methodology and implementation can be found in detail elsewhere, and will be discussed in more detail below [14, 31]. Briefly, each charge state was isolated and irradiated by one laser pulse of either 505 or 545 nm light, corresponding to the absorption maximum of the donor and the acceptor chromophore, respectively, (which undergo only minimal shifts upon covalent attachment).…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Action-FRET of a Gaseous Protein

Daly

Knight

Halim

et al. 2016

J. Am. Soc. Mass Spectrom.

Self Cite

View full text Add to dashboard Cite

Mass spectrometry is an extremely powerful technique for analysis of biological molecules, in particular proteins. One aspect that has been contentious is how much native solution-phase structure is preserved upon transposition to the gas phase by soft ionization methods such as electrospray ionization. To address this question—and thus further develop mass spectrometry as a tool for structural biology—structure-sensitive techniques must be developed to probe the gas-phase conformations of proteins. Here, we report Förster resonance energy transfer (FRET) measurements on a ubiquitin mutant using specific photofragmentation as a reporter of the FRET efficiency. The FRET data is interpreted in the context of circular dichroism, molecular dynamics simulation, and ion mobility data. Both the dependence of the FRET efficiency on the charge state—where a systematic decrease is observed—and on methanol concentration are considered. In the latter case, a decrease in FRET efficiency with methanol concentration is taken as evidence that the conformational ensemble of gaseous protein cations retains a memory of the solution phase conformational ensemble upon electrospray ionization. Graphical Abstractᅟ Electronic supplementary materialThe online version of this article (doi:10.1007/s13361-016-1449-2) contains supplementary material, which is available to authorized users.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Action-FRET of a Gaseous Protein

Daly

Knight

Halim

et al. 2016

J. Am. Soc. Mass Spectrom.

Self Cite

View full text Add to dashboard Cite

show abstract

“…For various rhodamine derivatives, the literature reports a systematic overestimation of the transition energy by as much as 0.6 eV with deviations from the rhodamine absorption band usually around 0.4 eV . We recently suggested for rhodamine 575 that the major part of this deviation is due to the negligence of correlation effects rather than nonverticality or thermochromism . Among correlated single reference methods, coupled cluster calculations provide a systematic way to include dynamic electron correlation, depending on the level of truncation of the cluster operator.…”

Section: Introductionmentioning

confidence: 99%

Excited States of Xanthene Analogues: Photofragmentation and Calculations by CC2 and Time‐Dependent Density Functional Theory

et al. 2016

Self Cite

View full text Add to dashboard Cite

Action spectroscopy has emerged as an analytical tool to probe excited states in the gas phase. Although comparison of gas-phase absorption properties with quantum-chemical calculations is, in principle, straightforward, popular methods often fail to describe many molecules of interest-such as xanthene analogues. We, therefore, face their nano- and picosecond laser-induced photofragmentation with excited-state computations by using the CC2 method and time-dependent density functional theory (TDDFT). Whereas the extracted absorption maxima agree with CC2 predictions, the TDDFT excitation energies are blueshifted. Lowering the amount of Hartree-Fock exchange in the DFT functional can reduce this shift but at the cost of changing the nature of the excited state. Additional bandwidth observed in the photofragmentation spectra is rationalized in terms of multiphoton processes. Observed fragmentation from higher-lying excited states conforms to intense excited-to-excited state transitions calculated with CC2. The CC2 method is thus suitable for the comparison with photofragmentation in xanthene analogues.

show abstract

Cryogenic Ion Fluorescence Spectroscopy: FRET in Rhodamine Homodimers and Heterodimers

Kjær,

Vu‐Phung,

Toft Lindkvist

et al. 2023

Chemistry A European J

View full text Add to dashboard Cite

The internal electronic communication between two or more light‐absorbers is fundamental for energy‐transport processes, a field of large current interest. Here we have studied the intrinsic photophysics of homo‐ and heterodimers of rhodamine cations where just two methylene units bridge the dyes. Gas‐phase experiments were done on frozen molecular ions at cryogenic temperatures using the newly built LUNA2 mass spectroscopy setup in Aarhus. Both absorption (from fluorescence excitation) and dispersed‐fluorescence spectra were measured. In the gas phase, there is no dielectric screening from solvent molecules, and the effect of charges on transition energies is maximum. Indeed, bands are redshifted compared to those of monomer dyes due to the electric field that each dye senses from the other in a dimer. Importantly, also, as two chemically identical dyes in a homodimer do not experience the same field along the long axis, each dye has separate absorption. At low temperatures, it is therefore possible to selectively excite one dye. We find that fluorescence is dominantly from the dye with the lowest transition energy no matter which dye is photoexcited. Hence our work unequivocally demonstrates Förster Resonance Energy Transfer even in homodimers where one dye acts as donor and the other as acceptor.

show abstract

Visible and Ultraviolet Spectroscopy of Gas Phase Rhodamine 575 Cations

Cited by 17 publications

References 50 publications

Action-FRET of a Gaseous Protein

Action-FRET of a Gaseous Protein

Excited States of Xanthene Analogues: Photofragmentation and Calculations by CC2 and Time‐Dependent Density Functional Theory

Cryogenic Ion Fluorescence Spectroscopy: FRET in Rhodamine Homodimers and Heterodimers

Contact Info

Product

Resources

About