Abstract
From a study of the u. v., visible, near i. r. and e. s. r. spectra induced by
γ
-irradiation at 77°K in glassy
MTHF
and in glassy
MTHF
containing various additives and from a study of controlled temperature increases on these spectra, the following conclusions are drawn. (1) The primary products of the radiolysis are electrons (
e
-
) and positive ions (
MTHF
+
) which undergo a rapid ion-molecule reaction to give O CH
3
radicals (
R
⋅). (2)
e
-
can either be trapped in the glassy
MTHF
matrix or can be captured by either napththalene, ferric chloride, carbon tetrachloride, nitrous oxide or
trans
-stilbene if these substances are present. (3) The
e
-
T
are bleachable by light or heat and disappear independently of the radicals R⋅ without either augmentation of R⋅ or the production of any new radical species. (4)
e
-
T
and R⋅ disappear thermally and independently by second-order reactions, the rate constants being
K
e
-
+
e
-
(M
-1
S
-1
) = 10
12⋅4±1⋅1
exp ─ [0⋅85 ± 0⋅10 kcal/mole/
R
(
T
─ 75)] and
K
R˙
+
R˙
(M
-1
S
-1
) = 10
13⋅3±1⋅4
exp ─ [1⋅20 ± 0⋅15 kcal/mole/
R
(
T
─ 75)]. These rate expressions suggest that both reactions are diffusion controlled at low temperatures in the glassy phase. (5) The kinetics of the thermal bleaching of
e
-
T
indicate that the electrons migrate distances of about 150 Å from their parent positive ions before being trapped in the matrix. (6) The effect of FeCl
3
in reducing the formation of
e
-
T
at 77°K and its lack of effect on the thermal bleaching of
e
-
T
suggests that the reaction
e
-
+ FeCl
3
→ FeCl
2
+ Cl
-
only occurs before the electron is thermalized.
Reference20 articles.
1. Trans;Ayseough P. B.;Faraday Soc.,1962
2. J;Boag J. W.;Amer. Ghem. Soc.,1962
3. Beta-radiolysis of liquid benzene
4. Collinson E. Dainton F. S. Smith D. R. & Tazuke S. 1962 Proc. Ghem. Soc. p. 1140.
5. Compton A. H. & Allison S. K. 1935 X -rays in theory and experiment. London: MacMillan and Co.
Cited by
94 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献