Experimental Femtosecond Photoionization of NaI

Jouvet, Christophe; Martrenchard, S.; Solgadi, D.; Dedonder‐Lardeux, C.; Mons, Michel; Grégoire, Gilles; Dimicoli, I.; Piuzzi, F.; Visticot, J. P.; Mestdagh, J. M.; D’Oliveira, P.; Meynadier, P.; Perdrix, M.

doi:10.1021/jp9639049

Cited by 78 publications

(107 citation statements)

References 22 publications

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“…1 shows exemplary delay scans extracted from our data at well-defined photoelectron energies of E k =1.8 ± .1 eV and E k =1.4 ± .1 eV, corresponding to the outer turn on the potential surface or to intra-molecular distances around the intersection, respectively. Similar response signals, characterizing the oscillating behavior were observed in [1,2,5]. However, our measurements can provide more detailed insights, as all electronic states of excited NaI, reachable with the ionizing probe pulses, were resolved at once ( fig.…”

Section: Introductionsupporting

confidence: 68%

“…The experiments presented here can be seen as an extension of our former study of Br 2 dissociation [4]. A TRPES study with femtosecond pulses on NaI molecules has previously been done in 1997 by Jouvet et al [5], but in their experiment they could only distinguish between slow and fast electrons, hence not using the advantage of resolving all electronic states simultaneously. In this contribution, we present the results from our recent experiments on the electronic structure dynamics in photo-excited NaI molecules in a photon wavelength range covering 320 nm to 370 nm.…”

Section: Introductionmentioning

confidence: 91%

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Coherent wave packet dynamics in photo-excited Nal

Leitner

Buchner

Luebcke

et al. 2013

EPJ Web of Conferences

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Section: Introductionsupporting

confidence: 68%

Section: Introductionmentioning

confidence: 91%

Coherent wave packet dynamics in photo-excited Nal

Leitner

Buchner

Luebcke

et al. 2013

EPJ Web of Conferences

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“…[1][2][3] In the presence of solvent molecules, the situation changes radically due to the strong coupling of the system ground and excited states with the interacting solvent field. 4 Visible or UV photoexcitation of many anionic solutes in solution and in clusters frequently leads to the appearance of optical charge-transfer absorption bands, located at lower ena͒ ergies than the vacuum detachment threshold; they are normally referred to as charge-transfer-to-solvent ͑CTTS͒ transitions.…”

Section: Introductionmentioning

confidence: 99%

“…Figure 1 depicts the spatial distribution of the CTTS electron excited from an I − ion and from a K + I − contact ion pair dissolved in ammonia, for a typical snapshot of a simulation run at a fluid density 1 * = 0.827 and T = 420 K. 22 Supercritical ammonia in the reduced density range 1 * = 0.07-0.83 was chosen as the solvent medium because by varying its density it was possible to have either free iodide ions or K + I − CIPs with sufficiently high concentrations to observe their optical absorption. 16 The optical excitation of iodide anions in supercritical NH 3 revealed that not only the free solvated anion but also the CIP species act as efficient CTTS donors. 16 However, the two CTTS states will exhibit marked differences between them due to the proximity of the potassium counterion to the donor in the CIP; K + ions dominate the solvent structure around the photoexcitable species producing substantial alterations with respect to the solvation structure in free iodide ion.…”

Section: Introductionmentioning

confidence: 99%

Short-range and long-range solvent effects on charge-transfer-to-solvent transitions of I− and K+I− contact ion pair dissolved in supercritical ammonia

Sciaini

Fernández‐Prini

Estrin

et al. 2007

The Journal of Chemical Physics

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Articles you may be interested inVertical excitation and electron detachment energies associated with the optical absorption of iodide ions dissolved in supercritical ammonia at 420 K have been calculated in two limiting scenarios: as a solvated free I − ion and forming a K + I − contact ion pair ͑CIP͒. The evolution of the transition energies as a result of the gradual building up of the solvation structure was studied for each absorbing species as the solvent's density increased, i.e., changing the NH 3 supercritical thermodynamic state. In both cases, if the solvent density is sufficiently high, photon absorption produces a spatially extended electron charge beyond the volume occupied by the solvated solute core; this excited state resembles a typical charge-transfer-to-solvent ͑CTTS͒ state. A combination of classical molecular dynamics simulations followed by quantum mechanical calculations for the ground, first-excited, and electron-detached electronic states have been carried out for the system consisting of one donor species ͑free I − ion or K + I − CIP͒ surrounded by ammonia molecules. Vertical excitation and electron detachment energies were obtained by averaging 100 randomly chosen microconfigurations along the molecular dynamics trajectory computed for each thermodynamic condition ͑fluid density͒. Short-and long-range contributions of the solventϪdonor interaction upon the CTTS states of I − and K + I − were identified by performing additional electronic structure calculations where only the solvent interaction due to the first neighbor molecules was taken into account. These computations, together with previous experimental evidence that we collected for the system, have been used to analyze the solvent effects on the CTTS transition. In this paper we have established the following: ͑i͒ the CTTS electron of free I − ion or K + I − CIP presents similar features, and it gradually localizes in close proximity of the iodine parent atom when the ammonia density is increased; ͑ii͒ for the free I − ion, the short-range solvent interaction contributes to the stabilization of the ground state more than it does for the CTTS excited state, which is evidenced experimentally as a blueshift in the maximum absorption of the CTTS transition when the density is increased; ͑iii͒ this effect is less noticeable for the K + I − ion pair, because in this case a tight solvation structure, formed by four NH 3 molecules wedged between the ions, appears at very low density and is very little affected by changes in the density; ͑iv͒ the long-range contribution to the solvent stabilization can be neglected for the K + I − CIP, since the main features of its electronic transition can be explained on the basis of the vicinity of the cation; ͑v͒ however, the long-range solvent field contribution is essential for the free I − ion to become an efficient CTTS donor upon photoexcitation, and this establishes a difference in the CTTS behavior of I − in bulk and in clusters.

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“…The pump-probe spectroscopy of NaI has been studied extensively [3,4,[15][16][17][18][19][20][21]. Figure 1 depicts the pump-probe scheme and the relevant potential curves for femtosecond photoelectron spectroscopy of the excited-state wave packet dynamics.…”

mentioning

confidence: 99%

Pump-Probe Photoionization Study of the Passage and Bifurcation of a Quantum Wave Packet Across an Avoided Crossing

et al. 2003

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The application of femtosecond pump-probe photoelectron spectroscopy to directly observe vibrational wave packets passing through an avoided crossing is investigated using quantum wave packet dynamics calculations. Transfer of the vibrational wave packet between diabatic electronic surfaces, bifurcation of the wave packet, and wave packet construction via nonadiabatic mixing are shown to be observable as time-dependent splittings of peaks in the photoelectron spectra. DOI: 10.1103/PhysRevLett.90.248303 PACS numbers: 82.20.Gk, 33.60.-q, 82.53.Eb, 82.53.Kp The concept of nonadiabatic transitions is fundamental to an understanding of chemical phenomena [1,2]. A typical example, and the one of interest here, is intramolecular electron transfer induced by vibrational motion in the excited state of alkali halides such as the NaI molecule. Pump-probe studies of this system have demonstrated the decrease of wave packet population on the excited adiabatic surface due to dissociation at the avoided crossing [3,4]. Oscillations in the population of the dissociative products (Na and I) due to the interference of wave packets on the covalent and ionic potentials merging at the avoided crossing have also been observed [3]. Although bifurcation of wave packets must be invoked to explain these observations, no real-time evidence of the instance of wave packet bifurcation has yet been experimentally observed. Such direct observation, if possible, would be interesting in itself, but also quite significant to studies of electron transfer, wave packet engineering, and reaction control through wave packet splitting and mixing. Also, from the perspective of quantum measurement, wave packet bifurcation corresponding to an intramolecular double-slit experiment will shed light on the evolution of quantum entanglement between electronic and nuclear motion [5]. Bifurcation and merging of wave packets are important as an intrinsic mechanism of ''quantum chaos,'' which has no simple classical counterpart [6 -8].Pump-probe photoelectron spectroscopy has been demonstrated to be a powerful means to monitor real-time reaction dynamics [9][10][11][12][13][14]. We here show theoretically that the method permits real-time observations of a wave packet passing through an avoided crossing, using excited-state dynamics of NaI as an example.The pump-probe spectroscopy of NaI has been studied extensively [3,4,[15][16][17][18][19][20][21]. Figure 1 depicts the pump-probe scheme and the relevant potential curves for femtosecond photoelectron spectroscopy of the excited-state wave packet dynamics. The adiabatic excited state features an extended well whose character changes from covalent at shorter distances to ionic at larger distances due to an avoided crossing with the ground state at 7 A [22,23]. In the diabatic representation, the same system is viewed as an ionic curve (here called V 1 ) intersecting a covalent curve (V 2 ), with an associated nonadiabatic interaction (V 12 ). The diabatic curves are shown in Fig. 1.The excited-state wave packet...

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Experimental Femtosecond Photoionization of NaI

Cited by 78 publications

References 22 publications

Coherent wave packet dynamics in photo-excited Nal

Coherent wave packet dynamics in photo-excited Nal

Short-range and long-range solvent effects on charge-transfer-to-solvent transitions of I− and K+I− contact ion pair dissolved in supercritical ammonia

Pump-Probe Photoionization Study of the Passage and Bifurcation of a Quantum Wave Packet Across an Avoided Crossing

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