The pulse radiolysis of decaborane-14 solutions

1976 ◽  
Vol 29 (1) ◽  
pp. 209 ◽  
Author(s):  
BJ Brown ◽  
DF Sangster
Keyword(s):  
Optical Absorption ◽  
Pulse Radiolysis ◽  
Solvated Electron ◽  
Lower Yield ◽  
Polar Solvents ◽  
Aqueous Acid ◽  
Solvent Systems

Results for the pulse radiolysis of B10H14 in selected solvent systems are reported. In polar solvents the solvated electron is rapidly scavenged by B10H14 with k >~ 2x1010 1. mol-1 s-1. In H2O, CH30H and C2H50H a transient optical absorption (G x ε ≈ 104 1. mol-1 cm-1) attributed to boranyl radicals is observed. A lower yield is observed in aqueous acid and hydrocarbon solutions and in the presence of electron scavengers. The results are consistent with an electron scavenging reaction leading to formation of a boranyl radical.

Étude par radiolyse pulsée des propriétés spectrales et cinétiques de l'électron solvaté dans l'hexane-1,2,6-triol liquide

1995 ◽  
Vol 73 (1) ◽  
pp. 117-122 ◽  
Author(s):  
J.-P. Jay-Gerin ◽  
J. Chevrel ◽  
C. Ferradini ◽  
E. Ray ◽  
M.H. Klapper ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Optical Absorption ◽  
Linear Accelerator ◽  
Pulse Radiolysis ◽  
Order Reaction ◽  
Kinetic Properties ◽  
Solvated Electron ◽  
Solvent Viscosity ◽  
First Order ◽  
Short Times

The optical absorption spectrum of the solvated electron (es−) in liquid hexane-1,2,6-triol has been measured by nanosecond pulse radiolysis at different temperatures (10–40 °C) to investigate the influence of high solvent viscosity values on the spectral and kinetic properties of es−. The wavelength at the absorption maximum, λmax, is equal to 560 nm, and its variation with temperature, if it exists in the considered zone, is less than the experimental error. At 20 °C and 150 ns, the value of the product [Formula: see text] of the yield of es− and the molar extinction coefficient at λmax is 2.55 × 104 molecule/(M cm 100 eV). In the context of this work, we have compared results obtained with both a linear accelerator and a Febetron, a comparison that has allowed us to evaluate the influence of variations of the dose per pulse and to extend measurements to short times. In the case of experiments performed with the linear accelerator, es− is found to decay at all wavelengths by a first-order reaction (or by a pseudo-first-order reaction) with an activation energy of ~45 kJ mol−1. By contrast, kinetic curves obtained with the Febetron seem to show a competition in which a second-order law is followed at short times. The fact that the shape of the spectra seems to vary as a function of the dose per pulse indicates the possible intervention of another species whose formation is favored by the use of high radiation doses. In other respects, the kinetics of electron solvation does not seem to be controlled by the viscosity of the solvent in our experimental conditions. Keywords: liquid hexane-1,2,6-triol, pulse radiolysis, linear accelerator and Febetron, solvated electron, optical absorption spectrum, kinetic properties, solvent viscosity, dose and temperature effects.

Temperature and density effects on the absorption maximum of solvated electrons in sub- and super-critical methanol

2010 ◽  
Vol 88 (10) ◽  
pp. 1026-1033 ◽  
Author(s):  
Y. Yan ◽  
M. Lin ◽  
Y. Katsumura ◽  
Y. Muroya ◽  
S. Yamashita ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Absorption Maximum ◽  
Pulse Radiolysis ◽  
Electron Pulse ◽  
Density Range ◽  
Supercritical State ◽  
Solvated Electron ◽  
Solvated Electrons ◽  
Absorption Energy ◽  
Increasing Temperature

The optical absorption spectra of the solvated electron ([Formula: see text]) in sub- and super-critical methanol are measured by both electron pulse radiolysis and laser photolysis techniques, at temperatures in the range 220–270 °C. Over the density range studied (~0.45–0.59 g/cm3), the position of the absorption maximum ([Formula: see text]) of [Formula: see text] is found to shift only slightly to the red with decreasing density. In agreement with our previous work in water, at a fixed pressure, [Formula: see text] decreases monotonically with increasing temperature in passing through the phase transition at Tc (239.5 °C). By contrast, at a fixed density, [Formula: see text] exhibits a minimum as the solvent passes above the critical point into the supercritical state. These behaviors are discussed in terms of microscopic arguments based on the changes that occur in the methanol properties and methanol structure in the sub- and super-critical regimes. The effect of the addition of a small amount of water to the alcohol on the optical absorption energy of [Formula: see text] is also investigated.

Article

1998 ◽  
Vol 76 (4) ◽  
pp. 411-413
Author(s):  
Yixing Zhao ◽  
Gordon R Freeman
Keyword(s):  
Absorption Spectrum ◽  
Optical Absorption ◽  
Temperature Dependence ◽  
Optical Absorption Spectrum ◽  
Infrared Light ◽  
Solvated Electron ◽  
Solvated Electrons ◽  
Tert Butanol ◽  
Solvent Dependence ◽  
Increasing Temperature

The energy and asymmetry of the optical absorption spectrum of solvated electrons, es- , change in a nonlinear fashion on changing the solvent through the series HOH, CH3OH, CH3CH3OH, (CH3)2CHOH, (CH3)3COH. The ultimate, quantum-statistical mechanical, interpretation of solvated electron spectra is needed to describe the solvent dependence. The previously reported optical spectrum of es- in tert-butanol was somewhat inaccurate, due to a small amount of water in the alcohol and to limitations of the infrared light detector. The present note records the remeasured spectrum and its temperature dependence. The value of the energy at the absorption maximum (EAmax) is 155 zJ (0.97 eV) at 299 K and 112 zJ (0.70 eV) at 338 K; the corresponding values of G epsilon max (10-22 m2 aJ-1) are 1.06 and 0.74. These unusually large changes are attributed to the abnormally rapid decrease of dielectric permittivity of tert-butanol with increasing temperature. The band asymmetry at 299 K is Wb/Wr = 1.8.Key words: optical absorption spectrum, solvated electron, solvent effects, tert-butanol, temperature dependence.

scholarly journals Pulse Radiolysis Studies of Collisional Deexcitation of Ne(3P1) by H2

2015 ◽  
Vol 19 (1) ◽  
pp. 75-78
Author(s):  
Deba Bahadur Khadka
Keyword(s):  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Cross Sections ◽  
Pulse Radiolysis ◽  
Science And Technology ◽  
Optical Absorption Spectroscopy ◽  
Time Resolved ◽  
Collisional Energy ◽  
The Mean ◽  
Collisional Deexcitation

The cross sections for the deexcitation of Ne(3P1) by H2 have been measured as a function of the mean collisional energy in the range of 17.3-37.9 meV or in the temperature range from 134 K to 293 K using a pulse radiolysis method as combined with time-resolved optical absorption spectroscopy. The deexcitation cross sections are in the range of 2.1- 5.6 Å2 for Ne(3P1) and nearly constant or increase slightly with increasing the collisional energy.Journal of Institute of Science and Technology, 2014, 19(1): 75-78

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