The 1,6- and 1,7-regioisomers of dinitro- (1,6-
A and 1,7-
A) and diamino-substituted perylene bisimides (1,6-
B and 1,7-
B), and 1-amino-6-nitro- and 1-amino-7-nitroperylene bisimides (1,6-
C and 1,7-
C) were synthesized. The 1,6-
A and 1,7-
A regioisomers were
[...] Read more.
The 1,6- and 1,7-regioisomers of dinitro- (1,6-
A and 1,7-
A) and diamino-substituted perylene bisimides (1,6-
B and 1,7-
B), and 1-amino-6-nitro- and 1-amino-7-nitroperylene bisimides (1,6-
C and 1,7-
C) were synthesized. The 1,6-
A and 1,7-
A regioisomers were successfully separated by high performance liquid chromatography and characterized by 500 MHz
1H-NMR spectroscopy, and subsequently, their reduction which afforded the corresponding diaminoperylene bisimides 1,6-
B and 1,7-
B, respectively. On the other hand, the monoreduction of 1,6-
A and 1,7-
A, giving the asymmetric 1-amino-6-nitro (1,6-
C) and 1-amino-7-nitroperylene bisimides (1,7-
C), respectively, can be performed by shortening the reaction time from 6 h to 1 h. This is the first time the asymmetric 1,6-disubstituted perylene bisimide 1,6-
C is obtained in pure form. The photophysical properties of 1,6-
A and 1,7-
A were found to be almost the same. However, the regioisomers 1,6-
C and 1,7-
C, as well as 1,6-
B and 1,7-
B, exhibit significant differences in their optical characteristics. Time-dependent density functional theory calculations performed on these dyes are reported in order to rationalize their electronic structure and absorption spectra.
Full article
