Ultrafast pump–probe spectroscopy of neutral FenOm clusters (n, m < 16)

2020 ◽  
Vol 22 (42) ◽  
pp. 24624-24632
Author(s):  
Jacob M. Garcia ◽  
Ryan E. Shaffer ◽  
Scott G. Sayres
Keyword(s):  
Iron Oxide ◽  
Oxidation State ◽  
Cluster Size ◽  
Pump Probe ◽  
Femtosecond Dynamics ◽  
Fe Oxidation ◽  
Probe Spectroscopy

The femtosecond dynamics of iron oxide clusters are shown to depend on both the cluster size and Fe oxidation state.

scholarly journals Ultrafast Pump-Probe Spectroscopy of Finite-Sized Neutral Iron Oxide Clusters

2020 ◽  
Author(s):  
Jacob Garcia ◽  
ryan shaffer ◽  
Scott Sayres
Keyword(s):  
Excited State ◽  
Iron Oxide ◽  
Cluster Size ◽  
Iron Oxidation ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Laser Vaporization ◽  
Relative Population ◽  
Pump Probe ◽  
Probe Spectroscopy

<div><p>Neutral iron oxide clusters (Fe<sub>n</sub>O<sub>m</sub>, n,m ≤ 16) are produced in a laser vaporization source using O<sub>2</sub>gas seeded in He. The neutral clusters are ionized with a sequence of femtosecond laser pulses and detected using time-of-flight mass spectrometry. Small clusters are confirmed to be most prominant in the stoichiometric (n = m) distribution, with m = n + 1 clusters observed above n = 4. Pump-probe spectroscopy is employed to study the dynamics of an electron transfer from an oxygen orbital to an iron nonbonding orbital of iron oxide clusters that is driven by absorption of a 400 nm photon. A bifurcation of the initial wavepacket occurs, where a femtosecond component is attributed to electron relaxation assisted through internuclear vibrational relaxation, and a slow relaxation shows the formation of a bound excited state. The lifetime and relative ratio of the two pathways depends on both the cluster size and iron oxidation state. The femtosecond lifetime decreases with increased cluster size until a saturation timescale is achieved at n > 5. The relative population of the long-lived excited state decreases with cluster size and suggests that the excited electron remains on the Fe atom for > 20 ps. </p></div>

scholarly journals Ultrafast Pump-Probe Spectroscopy of Finite-Sized Neutral Iron Oxide Clusters

2020 ◽  
Author(s):  
Jacob Garcia ◽  
ryan shaffer ◽  
Scott Sayres
Keyword(s):  
Excited State ◽  
Iron Oxide ◽  
Cluster Size ◽  
Iron Oxidation ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Laser Vaporization ◽  
Relative Population ◽  
Pump Probe ◽  
Probe Spectroscopy

<div><p>Neutral iron oxide clusters (Fe<sub>n</sub>O<sub>m</sub>, n,m ≤ 16) are produced in a laser vaporization source using O<sub>2</sub>gas seeded in He. The neutral clusters are ionized with a sequence of femtosecond laser pulses and detected using time-of-flight mass spectrometry. Small clusters are confirmed to be most prominant in the stoichiometric (n = m) distribution, with m = n + 1 clusters observed above n = 4. Pump-probe spectroscopy is employed to study the dynamics of an electron transfer from an oxygen orbital to an iron nonbonding orbital of iron oxide clusters that is driven by absorption of a 400 nm photon. A bifurcation of the initial wavepacket occurs, where a femtosecond component is attributed to electron relaxation assisted through internuclear vibrational relaxation, and a slow relaxation shows the formation of a bound excited state. The lifetime and relative ratio of the two pathways depends on both the cluster size and iron oxidation state. The femtosecond lifetime decreases with increased cluster size until a saturation timescale is achieved at n > 5. The relative population of the long-lived excited state decreases with cluster size and suggests that the excited electron remains on the Fe atom for > 20 ps. </p></div>

Ultrafast pump-probe spectroscopy: femtosecond dynamics in Liouville space

1989 ◽  
Vol 93 (25) ◽  
pp. 8149-8162 ◽  
Author(s):  
Yi Jing Yan ◽  
Laurence E. Fried ◽  
Shaul Mukamel
Keyword(s):  
Pump Probe ◽  
Liouville Space ◽  
Femtosecond Dynamics ◽  
Probe Spectroscopy

scholarly journals Ultrafast Electron/Energy Transfer and Intersystem Crossing Mechanisms in BODIPY-Porphyrin Compounds

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 312
Author(s):  
Yusuf Tutel ◽  
Gökhan Sevinç ◽  
Betül Küçüköz ◽  
Elif Akhuseyin Yildiz ◽  
Ahmet Karatay ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Spectra ◽  
Visible Region ◽  
Energy Transfer Mechanism ◽  
Free Base ◽  
Pump Probe ◽  
Harvesting Efficiency ◽  
Probe Spectroscopy ◽  
Absorption Features ◽  
Transfer Mechanisms

Meso-substituted borondipyrromethene (BODIPY)-porphyrin compounds that include free base porphyrin with two different numbers of BODIPY groups (BDP-TTP and 3BDP-TTP) were designed and synthesized to analyze intramolecular energy transfer mechanisms of meso-substituted BODIPY-porphyrin dyads and the effect of the different numbers of BODIPY groups connected to free-base porphyrin on the energy transfer mechanism. Absorption spectra of BODIPY-porphyrin conjugates showed wide absorption features in the visible region, and that is highly valuable to increase light-harvesting efficiency. Fluorescence spectra of the studied compounds proved that BODIPY emission intensity decreased upon the photoexcitation of the BODIPY core, due to the energy transfer from BODIPY unit to porphyrin. In addition, ultrafast pump-probe spectroscopy measurements indicated that the energy transfer of the 3BDP-TTP compound (about 3 ps) is faster than the BDP-TTP compound (about 22 ps). Since the BODIPY core directly binds to the porphyrin unit, rapid energy transfer was seen for both compounds. Thus, the energy transfer rate increased with an increasing number of BODIPY moiety connected to free-base porphyrin.

Classical theory of ultrafast pump-probe spectroscopy: Applications to I2 photodissociation in Ar solution

1994 ◽  
Vol 61 (1-3) ◽  
pp. 153-165 ◽  
Author(s):  
Robert M. Whitnell ◽  
Kent R. Wilson ◽  
YiJing Yan ◽  
Ahmed H. Zewail
Keyword(s):  
Classical Theory ◽  
Pump Probe ◽  
Probe Spectroscopy

Coherent pump–probe spectroscopy of a Λ system with a close lying excited level

2013 ◽  
Vol 88 (6) ◽  
pp. 065404 ◽  
Author(s):  
Niharika Singh ◽  
Ayan Ray ◽  
R D'Souza ◽  
Q V Lawande ◽  
B N Jagatap
Keyword(s):  
Excited Level ◽  
Pump Probe ◽  
Probe Spectroscopy

Ultrafast pump-probe spectroscopy of native etiolated oat phytochrome

Biochemistry ◽  
1993 ◽  
Vol 32 (29) ◽  
pp. 7512-7518 ◽  
Author(s):  
Sergei Savikhin ◽  
Todd Wells ◽  
Pill Soon Song ◽  
Walter S. Struve
Keyword(s):  
Pump Probe ◽  
Probe Spectroscopy

Investigation of Local Dynamics on the Sub-micron Scale in Organic Blends Using an Ultrafast Confocal Microscope

2010 ◽  
Vol 1270 ◽  
Author(s):  
Giulia Grancini ◽  
Dario Polli ◽  
Jenny Clark ◽  
Tersilla Virgili ◽  
Giulio Cerullo ◽  
...  
Keyword(s):  
Excited State ◽  
Confocal Microscopy ◽  
Polymer Blends ◽  
Spatial Resolution ◽  
Temporal Resolution ◽  
Electronic States ◽  
Pump Probe ◽  
Peculiar Behaviour ◽  
Spatio Temporal ◽  
Probe Spectroscopy

AbstractWe introduce a novel instrument combining femtosecond pump-probe spectroscopy and confocal microscopy for spatio-temporal imaging of excited-state dynamics of phase-separated polymer blends. Phenomena occurring at interfaces between different materials are crucial for optimizing the device performances, but are poorly understood due to the variety of possible electronic states and processes involved and to their complicated dynamics. Our instrument (with 200-fs temporal resolution and 300-nm spatial resolution) provides new insights into the properties of polymer blends, revealing spatially variable photo-relaxation paths and dynamics and highlighting a peculiar behaviour at the interface between the phase-separated domains.

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