Chemistry Reference
In-Depth Information
Table 6. 8 .
Stabilization energies of some cations and radicals relative to the correspond-
ing methyl species. (According to G. Koltzenburg, compiled in von Sonntag 1987)
kJ mol
−
1
kJ mol
−
1
Cation
Radical
+
CH
3
0
•
CH
3
0
+
CH
2
CH
3
•
CH
2
CH
3
630
71
+
CH
2
CH
2
CH
3
685
+
CH
2
CH(CH
3
)
2
825
+
CH(CH
3
)
2
•
CH(CH
3
)
2
965
122
+
C(CH
3
)
3
•
C(CH
3
)
3
119 5
193
+
CH
2
OCH
3
116 0
+
CH(OCH
3
)
2
CH
3
1350
+
CH(OCH
3
)
2
1490
+
C(OCH
3
)
3
158 0
The observation of this
γ
-elimination reaction has raised the question, whether
in DNA the related
C
(1
) radical can also lead to strand breakage. However due to
the negative charge at the phosphate group in 3
′
-elimi-
nation reaction (54) should be considerably slower than that of reaction (53).
′
-position, the rate of the
γ
Aromatic radical cations are readily formed and have a measurable lifetime
when they are stabilized by electron-donating substituents [e.g., reaction (55);
O'Neill et al. 1975].
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