Page 33 - Photoreactive Organic Thin Films
P. 33
12 HERMANN RAU
340 nm 360 nm 380 nm
A
AA
340
AA
5.0
• 1,2
1,0
0,8
0,6
^380
0.1 0.2 0.3 1,6 1.8 2.0 2.2 2.4
B
ht>
436 nm: E,E ~ E,z ; z,z
ITU,A hi>, A
D
FIGURE 1.5 (A) Reaction spectra for 436 nm photoisomerization of an azobenzenophane, pre-
irradiated by 313 nm to the photostationary state. (B) Nonlinear Mauser A plot of this photoisomeriza-
tion. T: pure E,E-form;T': pss at 436 nm irradiation; C': pss at 313 nm irradiation, nearly pure Z»Z form.
— 436 nm photoreaction: C' —» T' in ca 2 h. - - - - slow thermal reaction: C' —» T in ca. 10 d.
Thermal reaction: Y —» Y' in 10 min. After interrupting irradiation at Y. The slow thermal reaction
brings the system from Y' to T within days. (C) Linear Mauser ADQ2 plot and (D) the reaction scheme
(Adapted from reference 40, by permission.)
