1. Photoswitchable Intramolecular H-Stacking of Perylenebisimide
J. Am. Chem. Soc., 2010, 132,
Photoswitchable Intramolecular
H-Stacking of Perylenebisimide
Jiaobing Wang, Arterm Kulago, Wesley R. Browne*, Ben L. Feringa*
Center of Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands

2. Self-assembly and Aggregation
(Nature)
<Tobacoo Mosaic Virus>
A. Klug, Angew. Chem. Int. Ed., 1983, 22, 565 (Nobel Lecture).
(Artificial System)
S. Yagai et al., J. Am. Chem. Soc., 2009, 131, 5408.

3. Photoswitching of Aggregation
UV-light
S. Yagai et al., J. Am. Chem. Soc., 2005, 127,
(open-ring isomer)
(closed-ring isomer)
T. Fukaminato and M. Irie, Adv. Mater., 2006, 18, 3225.

4. Molecular Design “non-stacked” “H-stacked” Switching Unit
Fluorescence Unit
Fluorescence Unit

5. Aggregation of Perylenebisimide (PBI)4
・large absorption coefficient
・high-fluorescence quantum yield
・extremely high-stability
K. Müllen et al., Angew. Chem. Int. Ed., 2006, 45, 1401.
F. Wurthner et al., Chem. Eur. J., 2001, 7, 2245.

6. Molecular Design “non-stacked” “H-stacked” Switching Unit
Fluorescence Unit
Fluorescence Unit

7. Synthesis

8. Photoisomerization of 3
312 nm
(cis)
365 nm
(trans)
365 nm
312 nm
365 nm
312 nm
in THF, 20 ºC
F (trans → cis) : 0.159, F (cis → trans) : 0.078

9. Photoisomerization of 2
312 nm
(cis)
365 nm
(Absorption)
(Fluorescence)
in THF, 20 ºC
Concentration : 8 x 10-6 M
F (trans → cis) : 0.141, F (cis → trans) : 0.085

10. Photoisomerization of 1
312 nm
(cis)
365 nm
(Absorption)
(Fluorescence)
in THF, 20 ºC
Concentration : 4 x 10-6 M
F (trans → cis) : 0.091, F (cis → trans) : 0.045

11. S. Yagai et al., Angew. Chem. Int. Ed., 2008, 48, 3367.
Aggregation of PBI
H-Aggregate.
H-Aggregate.
J-Aggregate.
J-Aggregate.
S. Yagai et al., Angew. Chem. Int. Ed., 2008, 48, 3367.

12. Photoisomerization of 1
312 nm
(cis)
365 nm
(Absorption)
(Fluorescence)
in THF, 20 ºC
Concentration : 4 x 10-6 M
F (trans → cis) : 0.091, F (cis → trans) : 0.045

13. Concentration Dependence
F. Wurthner et al., Chem. Eur. J., 2001, 7, 2245.

14. 1H NMR Study of 2 a b c
in CD2Cl2, at 20 ºC

15. 1H NMR Study of 1 (312 nm, 10 min.) Conversion : 81 % (312 nm, 2 min.)
PBI-Hc
(312 nm, 10 min.)
PBI-Hb
Conversion : 81 %
(312 nm, 2 min.)
(before)
in CD2Cl2, at 20 ºC

16. Photoisomerization of 1
312 nm
(cis)
365 nm
(Fluorescence response)
<Conversion>
trans → cis (312 nm) : 81 % (NMR)
cis → trans (365 nm) : 83 %
(trans → cis) : 0.091, F (cis → trans) : 0.045

17. Conclusions
Light-driven dynamic control of intramolecular H-stacking of PBI units using a molecular switch is demonstrated.
The approach presented here allows for uniform and significant spectral changes spanning at least 4orders of magnitude of concentration.
This approach could be extended to control several processes such as molecular recognition, electron and energy transfer.