Page 985 - Advanced Organic Chemistry Part A - Structure and Mechanisms, 5th ed (2007) - Carey _ Sundberg

Scheme 11.1. Properties of Some Long-Lived Free Radicals 969
Structure Stability SECTION 11.1
Generation and
1 a Indefinitely stable as a solid, even in the Characterization of Free
presence of air
Radicals
.

2 b Ph Ph Crystalline substance is not rapidly attacked
by oxygen, although solutions are air-sensitive.
. The compound is stable to high temperature
Ph Ph in the absence of air.
Ph

6
3 c C Cl 5 Stable in solution for days, even in the
presence of air. Indefinitely stable in the
C Cl 5 . C Cl 5 solid state. Thermally stable up to 300°C.
6
6
4 d C(CH ) Persistent in dilute solution (<10 –5 M ) below
3 3
(CH 3 ) 3 C . of 50 s
–30°C in the absence of oxygen; t 1/2
H at 25°C.

5 e . CF(CF ) Thermally stable to 70°C; stable to O .
3 2
2
) CF
(CF 3 2 C
CF(CF )
3 2
) C
6 f (CH 3 3 C(CH ) Stable to oxygen; stable to extended storage
3 3
as a solid. Slowly decomposes in solution.
. O CH O
) C C(CH )
(CH 3 3 3 3
7 g . Stable distillable liquid that is only moderately
C H O C N CH 3 sensitive ot O 2 .
2 5
2

3 3
8 h (CH ) C Stable to oxygen, even above 100°C
N . . O .
(CH ) C
3 3
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b. K. Ziegler and B. Schnell, Liebigs Ann. Chem., 445, 266 (1925).
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d. G. D. Mendenhall, D. Griller, D. Lindsay, T. T. Tidwell, and K. U. Ingold, J. Am. Chem. Soc., 96, 2441 (1974).
e. K. V. Scherer, Jr., T. Ono, K. Yamanouchi, R. Fernandez, and P. Henderson, J. Am. Chem. Soc., 107, 718 (1985).
f. G. M. Coppinger J. Am. Chem. Soc., 79, 501 (1957); P. D. Bartlett and T. Funahashi, J. Am. Chem. Soc., 84, 2596 (1962).
g. J. Hermolin, M. Levin, and E. M. Kosower, J. Am. Chem. Soc., 103, 4808 (1981).
h. A. K. Hoffmann and A. T. Henderson, J. Am. Chem. Soc., 83, 4671 (1961).