Search our Database of Scientific Publications and Authors

I’m looking for a

    Details and Download Full Text PDF:
    Photochemical reaction dynamics in SO(2)-acetylene complexes.

    J Chem Phys 2010 Jun;132(22):224309
    Department of Physics, University of Puerto Rico, Rio Piedras, P.O. Box 23343, San Juan 00931-3343, Puerto Rico.
    The dynamics of photoinduced reactions between electronically excited SO(2) molecule (A (1)A(2)<--X (1)A(1)) and acetylene molecule (X (1)Sigma(g) (+)) in the SO(2)-acetylene van der Waals (vdW) complexes (clusters) was studied. The SO(2) molecule was excited by frequency-doubled radiation of a tunable dye laser, and resonance enhancement multiphoton photoionization of the produced photofragments was induced by ArF (193 nm) laser radiation or by frequency-doubled radiation of a second tunable dye laser to observe the C(2)H radical. The HOSO radical was detected by its IR emission. We found that the main photodecomposition channel of the vdW complexes (clusters) involves the SO(2) ( *)+C(2)H(2)-->HOSO+C(2)H reaction. Indeed, the analysis of the action spectra of the excitation laser radiation showed that the photofragments emerging in our experimental conditions (SO(2), 5%; C(2)H(2), 5%; and Xe; P(0)=2 atm) originate from the SO(2)...C(2)H(2) vdW complex (cluster). We analyzed the structure of this vdW complex theoretically, obtaining C(s) symmetry, with the acetylene molecule located above the OSO plane. The resonance-enhanced multiphoton photoionization action spectra of the C(2)H (A<--X) photofragmentation and the IR emission spectra of the HOSO radical allowed the authors to probe the energy distribution between the photofragments formed. The reaction that involves transition of the acetylene H atom to the SO(2) oxygen should be the primary step of the process considered, followed by nonstatistic dissociation of the vdW complex (cluster), with the C(2)H radical formed in its vibrationless state and excited both rotationally and translationally, and the HOSO radical excited vibrationally, rotationally and translationally. The proposed reaction mechanism was discussed, employing transition-state and Rice-Ramsperger-Kassel-Marcus (RRKM) approaches. The kinetics of photofragment formation was investigated, yielding characteristic radical build-up time of 0.64 micros.
    PDF Download - Full Text Link
    ( Please be advised that this article is hosted on an external website not affiliated with PubFacts.com)
    Source Status
    http://dx.doi.org/10.1063/1.3427414DOI ListingPossible

    Similar Publications

    Cluster-enhanced X-O2 photochemistry (X=CH3I, C3H6, C6H12, and Xe).
    J Chem Phys 2007 Mar;126(12):124316
    Institute of Chemical Kinetics and Combustion, Institutskaja Street 3, Novosibirsk, Russia.
    The effect of a local environment on the photodissociation of molecular oxygen is investigated in the van der Waals complex X-O(2) (X=CH(3)I, C(3)H(6), C(6)H(12), and Xe). A single laser operating at wavelengths around 226 nm is used for both photodissociation of the van der Waals complex and simultaneous detection of the O((3)P(J),J=2,1,0) atom photoproduct via (2+1) resonance enhanced multiphoton ionization. The kinetic energy distribution (KED) and angular anisotropy of the product O atom recoil in this dissociation are measured using the velocity map imaging technique configured for either full ("crush") or partial ("slice") detection of the three-dimensional O((3)P(J)) atom product Newton sphere. Read More
    Photodissociation of (SO2⋯XH) Van der Waals complexes and clusters (XH = C2H2, C2H4, C2H6) excited at 32,040-32,090 cm(-1) with formation of HSO2 and X.
    J Chem Phys 2014 Feb;140(5):054304
    Universidade do Algarve, FCT, DQF, and CIQA, P8005-139 Faro, Portugal.
    We studied photodecomposition dynamics of (SO2⋯XH) Van der Waals' (VdW) complexes and clusters in gas phase, with X = C2H, C2H3, and C2H5. SO2 was excited by frequency-doubled radiation of a tunable dye laser and resonance-enhanced multiphoton ionization was used to detect the C2H (m/z 25), C2H3 (m/z 27), and C2H5 (m/z 29) ions by time-of-flight mass spectroscopy. Spectra obtained at higher nozzle pressures (P0 > 2. Read More
    Photodissociation of van der Waals clusters of isoprene with oxygen, C5H8-O2, in the wavelength range 213-277 nm.
    J Chem Phys 2012 Aug;137(5):054305
    Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 ED Nijmegen, The Netherlands.
    The speed and angular distribution of O atoms arising from the photofragmentation of C(5)H(8)-O(2), the isoprene-oxygen van der Waals complex, in the wavelength region of 213-277 nm has been studied with the use of a two-color dissociation-probe method and the velocity map imaging technique. Dramatic enhancement in the O atoms photo-generation cross section in comparison with the photodissociation of individual O(2) molecules has been observed. Velocity map images of these "enhanced" O atoms consisted of five channels, different in their kinetic energy, angular distribution, and wavelength dependence. Read More
    Ultraviolet photodissociation dynamics of the phenyl radical.
    J Chem Phys 2012 Jan;136(4):044308
    Department of Chemistry, University of California at Riverside, Riverside, California 92521, USA.
    Ultraviolet (UV) photodissociation dynamics of jet-cooled phenyl radicals (C(6)H(5) and C(6)D(5)) are studied in the photolysis wavelength region of 215-268 nm using high-n Rydberg atom time-of-flight and resonance enhanced multiphoton ionization techniques. The phenyl radicals are produced from 193-nm photolysis of chlorobenzene and bromobenzene precursors. The H-atom photofragment yield spectra have a broad peak centered around 235 nm and are in good agreement with the UV absorption spectra of phenyl. Read More