Chemistry Letters 2002
477
Figure 3. Absorption spectral changes of the amorphous
Figure 1. Absorption spectra of hexane solutions of 1a
(3:8 Â 10À5 mol/l, solid line), 1b (broken line), and photo-
stationary state (dotted line) under irradiation with 280nm
light.
film (3 ꢁm thickness) prepared by oxidation polymerization
of 1a; solid line: before UV irradiation, broken line: after UV
irradiation.
Ministry of Education, Science, Sports, and Culture, and by
CREST and ACT of Japan Science and Technology Cooperation
(JST).
References and Notes
1
H. Duerr and H. Bouas-Laurent, ‘‘Photochromism: Molecules
and Systems,’’ Elsevir, Amsterdam (1990).
2
M. Irie, Chem. Rev., 100, 1685 (2000); M. Irie and M. Mohri,
J. Org. Chem., 53, 803 (1988); M. Irie and K. Uchida, Bull.
Chem. Soc. Jpn., 73, 985 (1998); S. H. Kawai, S. L. Gilat, and
J.-M. Lehn, Chem. Eur. J., 1, 285 (1995); G. M. Tsivgoulis
and J.-M. Lehn, Chem. Eur. J., 2, 1399 (1996).
3
N. Tanio and M. Irie, Jpn. J. Appl. Phys., 33, 1914 (1994); T.
Tsujioka, F. Tatezono, T. Harada, K. Kuroki, and M. Irie, Jpn.
J. Appl. Phys., 33, 5788 (1994).
4
5
S. Abe, K. Uchida, I. Yamazaki, and M. Irie, Langmuir, 13,
5504 (1997).
S. Kobatake, K. Shibata, K. Uchida, and M. Irie, J. Am. Chem.
Soc., 122, 12135 (2000); M. Irie, T. Lifka, S. Kobatake, and N.
Kato, J. Am. Chem. Soc., 122, 4871 (2000); T. Yamada, S.
Kobatake, K. Muto, and M. Irie, J. Am. Chem. Soc., 122, 1589
(2000); M. Irie, K. Uchida, T. Eriguchi, and H. Tsuzuki,
Chem. Lett., 1995, 899.
Figure 2. IR spectral changes of the
diarylethene 1a before (solid line) and
after polymerization (broken line).
absorption band attributable OH group disappeared in the FT IR
spectrum of the polymer film as shown in Figure 2.
6
7
T. Kawai, N. Fukuda, D. Groeschl, S. Kobatake, and M. Irie,
Jpn. J. Appl. Phys., 38, L1194 (1999); H. Utsumi, D.
Nagahama, H. Nakano, and Y. Shirota, J. Mater. Chem., 10,
2436 (2000).
1a: colorless needles; mp 93.5–94.9 ꢁC; 1H-NMR (400 MHz,
CDCl3) ¼ 1:82 (s, 3H, ap 2-Me), 1.88 (s, 3H, p 2-Me), 2.36 (s,
3H, ap 4-Me), 2.42 (s, 3H, p 4-Me), 6.93–7.00 ppm (m, 8H,
aromatic protons); (the ratio of ap: p isomers ¼ 1 : 1).
M. Irie, K. Sakemura, M. Okinaka, and K. Uchida, J. Org.
Chem., 60, 8305 (1995).
The polymer film p(1a) showed a reversible photochromic
reaction by alternate irradiation with UV and visible light. The
spectral change of the film is shown in Figure 3. X-ray diffraction
measurement showed no peaks even after 1 year storage at room
temperature. This indicates that the polymer film is in the
amorphous phase. The new amorphous photochromic film will be
applicable for wave-guide and novel recording media.
8
9
This work was supported by Sumitomo Foundation, a Grant-
in-Aid for Scientific Research (C) No. 12640567 from the
A. S. Hay, Polym. Eng. Sci., 16, 1 (1976).