Iodomethane

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 1440 Experts worldwide ranked by ideXlab platform

Maoping Song - One of the best experts on this subject based on the ideXlab platform.

Benjamin Erk - One of the best experts on this subject based on the ideXlab platform.

  • photodissociation of aligned ch3i and c6h3f2i molecules probed with time resolved coulomb explosion imaging by site selective extreme ultraviolet ionization
    Structural Dynamics, 2018
    Co-Authors: Kasra Amini, Cedric Bomme, Evgeny Savelyev, Felix Brause, N Berrah, M Brouard, Michael Burt, Lauge Christensen, S Dusterer, Benjamin Erk
    Abstract:

    We explore time-resolved Coulomb explosion induced by intense, extreme ultraviolet (XUV) femtosecond pulses from a free-electron laser as a method to image photo-induced molecular dynamics in two molecules, Iodomethane and 2,6-difluoroiodobenzene. At an excitation wavelength of 267 nm, the dominant reaction pathway in both molecules is neutral dissociation via cleavage of the carbon–iodine bond. This allows investigating the influence of the molecular environment on the absorption of an intense, femtosecond XUV pulse and the subsequent Coulomb explosion process. We find that the XUV probe pulse induces local inner-shell ionization of atomic iodine in dissociating Iodomethane, in contrast to non-selective ionization of all photofragments in difluoroiodobenzene. The results reveal evidence of electron transfer from methyl and phenyl moieties to a multiply charged iodine ion. In addition, indications for ultrafast charge rearrangement on the phenyl radical are found, suggesting that time-resolved Coulomb exp...

  • Photodissociation of aligned CH3I and C6H3F2I molecules probed with time-resolved Coulomb explosion imaging by site-selective extreme ultraviolet ionization
    AIP Publishing LLC and ACA, 2018
    Co-Authors: Kasra Amini, Cedric Bomme, Evgeny Savelyev, N Berrah, M Brouard, Michael Burt, Lauge Christensen, S Dusterer, Felix Brauße, Benjamin Erk
    Abstract:

    We explore time-resolved Coulomb explosion induced by intense, extreme ultraviolet (XUV) femtosecond pulses from a free-electron laser as a method to image photo-induced molecular dynamics in two molecules, Iodomethane and 2,6-difluoroiodobenzene. At an excitation wavelength of 267 nm, the dominant reaction pathway in both molecules is neutral dissociation via cleavage of the carbon–iodine bond. This allows investigating the influence of the molecular environment on the absorption of an intense, femtosecond XUV pulse and the subsequent Coulomb explosion process. We find that the XUV probe pulse induces local inner-shell ionization of atomic iodine in dissociating Iodomethane, in contrast to non-selective ionization of all photofragments in difluoroiodobenzene. The results reveal evidence of electron transfer from methyl and phenyl moieties to a multiply charged iodine ion. In addition, indications for ultrafast charge rearrangement on the phenyl radical are found, suggesting that time-resolved Coulomb explosion imaging is sensitive to the localization of charge in extended molecules

  • imaging charge transfer in Iodomethane upon x ray photoabsorption
    Science, 2014
    Co-Authors: Benjamin Erk, Rebecca Boll, L Foucar, Richard Coffee, Sebastian Trippel, Denis Anielski, Benedikt Rudek, Sascha W Epp, Sebastian Carron
    Abstract:

    Studies of charge transfer are often hampered by difficulties in determining the charge localization at a given time. Here, we used ultrashort x-ray free-electron laser pulses to image charge rearrangement dynamics within gas-phase Iodomethane molecules during dissociation induced by a synchronized near-infrared (NIR) laser pulse. Inner-shell photoionization creates positive charge, which is initially localized on the iodine atom. We map the electron transfer between the methyl and iodine fragments as a function of their interatomic separation set by the NIR–x-ray delay. We observe signatures of electron transfer for distances up to 20 angstroms and show that a realistic estimate of its effective spatial range can be obtained from a classical over-the-barrier model. The presented technique is applicable for spatiotemporal imaging of charge transfer dynamics in a wide range of molecular systems.

Mei Zhu - One of the best experts on this subject based on the ideXlab platform.

Cedric Bomme - One of the best experts on this subject based on the ideXlab platform.

  • photodissociation of aligned ch3i and c6h3f2i molecules probed with time resolved coulomb explosion imaging by site selective extreme ultraviolet ionization
    Structural Dynamics, 2018
    Co-Authors: Kasra Amini, Cedric Bomme, Evgeny Savelyev, Felix Brause, N Berrah, M Brouard, Michael Burt, Lauge Christensen, S Dusterer, Benjamin Erk
    Abstract:

    We explore time-resolved Coulomb explosion induced by intense, extreme ultraviolet (XUV) femtosecond pulses from a free-electron laser as a method to image photo-induced molecular dynamics in two molecules, Iodomethane and 2,6-difluoroiodobenzene. At an excitation wavelength of 267 nm, the dominant reaction pathway in both molecules is neutral dissociation via cleavage of the carbon–iodine bond. This allows investigating the influence of the molecular environment on the absorption of an intense, femtosecond XUV pulse and the subsequent Coulomb explosion process. We find that the XUV probe pulse induces local inner-shell ionization of atomic iodine in dissociating Iodomethane, in contrast to non-selective ionization of all photofragments in difluoroiodobenzene. The results reveal evidence of electron transfer from methyl and phenyl moieties to a multiply charged iodine ion. In addition, indications for ultrafast charge rearrangement on the phenyl radical are found, suggesting that time-resolved Coulomb exp...

  • Photodissociation of aligned CH3I and C6H3F2I molecules probed with time-resolved Coulomb explosion imaging by site-selective extreme ultraviolet ionization
    AIP Publishing LLC and ACA, 2018
    Co-Authors: Kasra Amini, Cedric Bomme, Evgeny Savelyev, N Berrah, M Brouard, Michael Burt, Lauge Christensen, S Dusterer, Felix Brauße, Benjamin Erk
    Abstract:

    We explore time-resolved Coulomb explosion induced by intense, extreme ultraviolet (XUV) femtosecond pulses from a free-electron laser as a method to image photo-induced molecular dynamics in two molecules, Iodomethane and 2,6-difluoroiodobenzene. At an excitation wavelength of 267 nm, the dominant reaction pathway in both molecules is neutral dissociation via cleavage of the carbon–iodine bond. This allows investigating the influence of the molecular environment on the absorption of an intense, femtosecond XUV pulse and the subsequent Coulomb explosion process. We find that the XUV probe pulse induces local inner-shell ionization of atomic iodine in dissociating Iodomethane, in contrast to non-selective ionization of all photofragments in difluoroiodobenzene. The results reveal evidence of electron transfer from methyl and phenyl moieties to a multiply charged iodine ion. In addition, indications for ultrafast charge rearrangement on the phenyl radical are found, suggesting that time-resolved Coulomb explosion imaging is sensitive to the localization of charge in extended molecules

  • charge transfer in dissociating Iodomethane and fluoromethane molecules ionized by intense femtosecond x ray pulses
    Structural Dynamics, 2016
    Co-Authors: Rebecca Boll, Thomas Kierspel, Cedric Bomme, Mitchell Burkett, Sebastian Carron, Ken R Ferguson, Richard Coffee, Sebastian Trippel, John D Bozek, L Foucar
    Abstract:

    Ultrafast electron transfer in dissociating Iodomethane and fluoromethane molecules was studied at the Linac Coherent Light Source free-electron laser using an ultraviolet-pump, X-ray-probe scheme. The results for both molecules are discussed with respect to the nature of their UV excitation and different chemical properties. Signatures of long-distance intramolecular charge transfer are observed for both species, and a quantitative analysis of its distance dependence in Iodomethane is carried out for charge states up to I21+. The reconstructed critical distances for electron transfer are in good agreement with a classical over-the-barrier model and with an earlier experiment employing a near-infrared pump pulse.

Dl Phillips - One of the best experts on this subject based on the ideXlab platform.

  • Short-time photodissociation dynamics of 1-chloro-2-iodoethane from resonance Raman spectroscopy
    'Hindawi Limited', 1999
    Co-Authors: Dl Phillips, Zheng X
    Abstract:

    We have obtained A-band absorption resonance Raman spectra of 1-chloro-2-iodoethane in cyclohexane solution. We have done preliminary time-dependent wavepacket calculations to simulate the resonance Raman intensities and absorption spectrum in order to learn more about the short-time photodissociation dynamics. We compare our preliminary results for 1-chloro-2-iodoethane with previous resonance Raman results for iodoethane and find that there appears to be more motion along non-C-I stretch modes for 1-chloro-2-iodoethane than for iodoethane. This is consistent with results of TOF photofragment spectroscopy experiments which indicate much more internal excitation of the photoproducts from 1-chloro-2-iodoethane photodissociation than the photoproducts from iodoethane photodissociation. © 1999 OPA (Overseas Publishers Association) N.V. Published by licensed under the Harwood Academic Publishers imprint, part of The Gordon and Breach Publishing Group.published_or_final_versio

  • Investigation of the short-time photodissociation dynamics of trans-1-bromo-2-iodoethane in the A-band absorption
    'AIP Publishing', 1999
    Co-Authors: Zheng X, Dl Phillips
    Abstract:

    We have obtained resonance Raman spectra and absolute Raman cross section measurements at five excitation wavelengths within the A-band absorption for 1-bromo-2-iodoethane in cyclohexane solution. The resonance Raman spectra have most of their intensity in the fundamentals, overtones, and combination bands of six Franck-Condon active vibrational modes; the nominal CCI bend, C-I stretch, C-Br stretch, C-C stretch, CH 2 wag with the Br atom attached to the CH 2 group, and CH 2 wag with the I atom attached to the CH 2 group. The resonance Raman intensities and A-band absorption spectrum were simulated using a simple model and time-dependent wave packet calculations. The simulation results and normal mode descriptions were used to find the short-time photodissociation dynamics in terms of internal coordinate displacements. The A-band short-time photodissociation dynamics for trans-1-bromo-2-iodoethane show that the C-I, C-Br, and C-C bonds as well as the CCI, CCBr, HCC, ICH, and BrCH angles have significant changes during the initial stages of the photodissociation reaction. This indicates the photodissociation reaction has a large degree of multidimensional character and suggests that the bromoethyl photofragment receives substantial internal excitation in so far as the short-time photodissociation dynamics determines the energy partitioning. Comparison of our results for 1-bromo-2-iodoethane with the A-band short-time dynamics of iodoethane, 1-chloro-2-iodoethane, and 1,2-diiodoethane and the trends observed for their A-band absorption spectra suggest that both the C-I and C-Br bonds experience a noticeable amount of photoexcitation. © 1999 American Institute of Physics.published_or_final_versio

  • Femtosecond photodissociation dynamics of 1,1,1-trifluoro-2-iodoethane in the Franck-Condon region
    TAYLOR & FRANCIS LTD, 1997
    Co-Authors: Wm Kwok, Dl Phillips
    Abstract:

    We report resonance Raman spectra of 1,1,1-trifluoro-2-iodoethane in cyclohexane taken with excitation wavelengths within the A-band absorption. The experimental A-band resonance Raman intensities and absorption spectrum were simulated using time-dependent wavepacket calculations and a simple model. The results of the time-dependent wavepacket calculations were used in conjunction with the normal mode descriptions found from normal coordinate calculations to obtain the short-time photodissociation dynamics (at 15 fs) of 1,1,1-trifluoro-2-iodoethane. The short-time photodissociation dynamics of 1,1,1-trifluoro-2-iodoethane has a large amount of multidimensional character and is qualitatively consistent with an impulsive 'semi-rigid' radical model of the photodissociation dynamics that shows the CF3CH2 radical going towards a more planar geometry about the CH2 carbon atom as the C-I bond is being broken. Our resonance Raman intensity analysis indicates that in the beginning stages of the photodissociation in the Franck-Condon region the C-C bond becomes longer, the CCI angle becomes smaller, the HCH and CCH angles become larger, two of the FCC angles (out of the CCI plane) become larger while the third FCC angle (in the CCI plane) becomes smaller, and there is some motion in the FCF angles and C-F bond lengths that is either positive or negative in sign, depending on the sign combination of the normal mode displacements. We also compare the photodissociation dynamics of 1,1,1-trifluoro-2-iodoethane with that of iodoethane

  • Femtosecond photodissociation dynamics of 1,1,1-trifluoro-2-iodoethane in the Franck-Condon region
    'Informa UK Limited', 1997
    Co-Authors: Dl Phillips, Wm Kwok
    Abstract:

    We report resonance Raman spectra of 1,1,1-trifluoro-2-iodoethane in cyclohexane taken with excitation wavelengths within the A-band absorption. The experimental A-band resonance Raman intensities and absorption spectrum were simulated using time-dependent wavepacket calculations and a simple model. The results of the time-dependent wavepacket calculations were used in conjunction with the normal mode descriptions found from normal coordinate calculations to obtain the short-time photodissociation dynamics (at 15 fs) of 1,1,1,-trifluoro-2-iodoethane. The short-time photodissociation dynamics of 1,1,1-trifluoro-2-iodoethane has a large amount of multidimensional character and is qualitatively consistent with an impulsive 'semi-rigid' radical model of the photodissociation dynamics that shows the CF 3CH 2 radical going towards a more planar geometry about the CH 2 carbon atom as the C-I bond is being broken. Our resonance Raman intensity analysis indicates that in the beginning stages of the photodissociation in the Franck-Condon region the C-C bond becomes longer, the CCI angle becomes smaller, the HCH and CCH angles become larger, two of the FCC angles (out of the CCI plane) become larger while the third FCC angle (in the CCI plane) becomes smaller, and there is some motion in the FCF angles and C-F bond lengths that is either positive or negative in sign depending on the sign combination of the normal mode displacements. We also compare the photodissociation dynamics of 1,1,1-trifluoro-2-iodoethane with that of iodoethane.link_to_subscribed_fulltex

Related terms

Iodomethane - 15 days free trial to Access Experts & Abstracts