H. Ikemoto et al. / Tetrahedron Letters 42 (2001) 6873–6875
6875
H.; Yamada, J.; Schmitt, S.; Hafner, K. Mol. Cryst. Liq.
Cryst. 2000, 348, 1; (b) Nakatsuji, S.; Ogawa, Y.;
Takeuchi, S.; Akutsu, H.; Yamada, J.; Naito, A.; Sudo,
K.; Yasuoka, N. J. Chem. Soc., Perkin Trans. 2 2000,
1969; (c) Ojima, T.; Akutsu, H.; Yamada, J.; Nakatsuji,
S. Chem. Lett. 2000, 918; (d) Nakatsuji, S.; Takeuchi, S.;
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Cryst. Liq. Cryst. 2001, 356, 33; (f) Akutsu, H.; Yamada,
J.; Nakatsuji, S. Chem. Lett. 2001, 208.
4. Kaszynski, P. In Magnetic Properties of Organic Materi-
als; Lahti, P. M., Ed.; Marcel Dekker: New York, Basel,
1999; Chapter 15, p. 305.
5
6
7
. Mizumoto, M.; Ikemoto, H.; Akutsu, H.; Yamada, J.;
Nakatsuji, S. Mol. Cryst. Liq. Cryst. 2001, 363, 149.
. Cf. Chuaed, T.; Deschenaux, R. Helv. Chem. Acta 1996,
79, 736.
. Ullman, E. F.; Osiecki, J. H.; Boocock, D. G. B.; Darcy,
Figure 2. Temperature dependence of paramagnetic suscepti-
R. J. Am. Chem. Soc. 1972, 94, 7049.
8. All aminoxyls described in this paper were characterized
bility ( ) for 3b between 2 and 373 K. The inset is the
p
enlarged figure over 300 K.
by HI-MS data and/or elemental analyses.
9
. The DSC measurements were carried out between the
temperature range 50°C to the temperature ca. 20°C over
the melting point of each radical, e.g. 50–110°C for the
radical 3b at a rate of 2°C/min. So far, we have not
observed any distinct appearance of a texture in 3b by
polarizing microscope investigation, suggesting that the
latter phase of 3b consists of another polymorphic form.
a new phase, but, no single crystal suitable for X-ray
analysis is available so far for the latter phase and the
crystal growth of the corresponding phase is currently
under study.
1
0. Crystal data for 3b with Curie–Weiss behaviour:
C H N O , FW=547.77, triclinic (P1), a=5.768(1), b=
, h=84.860(3), i=86.644(3), k=
Acknowledgements
(
3
4
47
2
4
1
8
4.89(2), c=18.637(3) A
5.737(3)°, V=1583.9(4) A
,
3
,
, T=295 K, Z=2, Dc=1.199
Mg m , R=0.119, wR=0.136 [2401 reflections and 361
−
3
We thank Professor Masao Hashimoto of Kobe Uni-
versity for providing us with the opportunity to use an
X-ray facility. This work was supported by a Grant-in-
Aid for Scientific Research on Priority Area (A) ‘Cre-
ation of Delocalized Electronic Systems’ (No.
0146250) from the Ministry of Education, Science,
Sports and Culture, Japan, which is gratefully
acknowledged.
parameters with I >3|(I)].
0
11. The susceptibility measurement for the radical 3b with
initial Curie–Weiss behaviour was carried out as follows:
2 K300 K373 K300 K2 K. Another measure-
ment was studied in a similar manner for a different
sample of the same radical with a different magnetic
behaviour of ST model. However, the behaviour
remained unchanged in this case to show again that of an
ST model, suggesting that the above change is the irre-
versible one (see text).
1
References
1
2. The -values are expressed in the following equation of
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