Thermal ring closure in Mo(CO)5L (L = bpy, dmbpy, dpbpy) transients generated by pulsed laser flash photolysis. Mechanistic information from high-pressure effects

1992 ◽  
Vol 11 (6) ◽  
pp. 2319-2322 ◽  
Author(s):  
Kedika Bal Reddy ◽  
Rudiger Hoffmann ◽  
Gabor Konya ◽  
Rudi Van Eldik ◽  
Edward M. Eyring
Keyword(s):  
High Pressure ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Pulsed Laser ◽  
Laser Flash ◽  
Ring Closure ◽  
Pressure Effects ◽  
High Pressure Effects

Chelate ring closure in (o-phenanthroline)pentacarbonylmetal transients (metal = chromium, molybdenum, tungsten) generated by pulsed laser flash photolysis

1991 ◽  
Vol 30 (2) ◽  
pp. 355-356 ◽  
Author(s):  
Shulin. Zhang ◽  
Volker. Zang ◽  
Gerard R. Dobson ◽  
Rudi. Van Eldik
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Chelate Ring ◽  
Pulsed Laser ◽  
Laser Flash ◽  
Ring Closure

scholarly journals Formation and Properties of Peroxynitrite as Studied by Laser Flash Photolysis, High-Pressure Stopped-Flow Technique, and Pulse Radiolysis Volume 10, Number 11, November 1997, pp 1285−1292

1998 ◽  
Vol 11 (5) ◽  
pp. 557-557 ◽  
Author(s):  
Reinhard Kissner ◽  
Thomas Nauser ◽  
Pascal Bugnon ◽  
Peter G. Lye ◽  
Willem H. Koppenol
Keyword(s):  
High Pressure ◽  
Pulse Radiolysis ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Stopped Flow

Application of high pressure laser flash photolysis in studies on selected hemoprotein reactions

2008 ◽  
Vol 1784 (11) ◽  
pp. 1481-1492 ◽  
Author(s):  
Małgorzata Brindell ◽  
Iwona Stawoska ◽  
Łukasz Orzeł ◽  
Przemysław Łabuz ◽  
Grażyna Stochel ◽  
...  
Keyword(s):  
High Pressure ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash

Laser flash photolysis study of (E)-1-(2′-arylidene-1′-phenylhydrazinyl)-1,2-dibenzoylalkenes: Mechanistic aspects of photochemical ring closure

1987 ◽  
Vol 37 (1) ◽  
pp. 147-157
Author(s):  
K. Bhattacharyya ◽  
S. Pratapan ◽  
P.M. Scaria ◽  
P.K. Das ◽  
M.V. George
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Ring Closure

Far-UV laser flash photolysis in solution. A time-resolved spectroscopic study of the chemistry of 1,1-dimethyl-1,3-(1-sila)-butadiene

1997 ◽  
Vol 75 (7) ◽  
pp. 975-982 ◽  
Author(s):  
Corinna Kerst ◽  
Martin Byloos ◽  
William J. Leigh
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Activation Parameters ◽  
Laser Flash ◽  
Ring Closure ◽  
Time Resolved ◽  
Decay Rate Constant ◽  
Hydrocarbon Solvents ◽  
First Order Kinetics ◽  
193 Nm

Laser flash photolysis (193 nm) of 1,1-dimethyl-(1-sila)cyclobut-2-ene in hexane solution leads to the formation of a transient species [Formula: see text] assigned to 1,1-dimethyl-1,3-(1-sila)butadiene on the basis of its UV absorption spectrum (λmax = 312 nm), and reactivity toward methanol (kMeOH = (3.6 ± 0.1) × 109 M−1 s−1; kH/kD = 1.3 ± 0.1), ethanol (kEtOH = (2.41 ± 0.06) × 109 M−1 s−1), tert-butanol (kBuOH = (1.8 ± 0.1) × 109 M−1 s−1; kH/kD = 1.5 ± 0.1), and oxygen [Formula: see text]. Experiments using isooctane and acetonitrile as solvent are also described. In acetonitrile, the lifetime of the silene is shortened considerably compared to hydrocarbon solvents, presumably due to quenching by adventitious water. In isooctane, under conditions of low excitation intensity, the siladiene decays with clean pseudo-first-order kinetics and a maximum lifetime of ~ 5 μs at 23 °C. The decay rate constant varies only slightly with temperature over the 20–60 °C range, leading to Arrhenius activation parameters of Ea = 0.5 ± 0.2 kcal/mol and log A = 5.7 ± 0.2. While steady state irradiation experiments suggest that in the absence of silene traps the predominant fate of the silabutadiene is thermal ring closure to regenerate the precursor, it is concluded that the rate constants and activation parameters for decay of the siladiene measured by flash photolysis represent a composite of those due to thermal electrocyclic ring closure (with Ea > ~3 kcal/mol) and reaction with adventitious quenchers (probably water, with Ea < 0). The measured Arrhenius parameters for reaction of the siladiene with methanol in isooctane (Ea = −2.6 ± 0.3 kcal/mol and log A = 7.6 ± 0.3) are consistent with this proposal. The potential and limitations of the use of 193-nm laser excitation for flash photolysis studies in solution are discussed. Keywords: far-UV, silene, flash photolysis, kinetics, electrocyclic.

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