title: 1,6- and 1,7-regioisomers of asymmetric and symmetric perylene bisimides: synthesis, characterization and optical properties.
abstract: 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.
authors.affiliation: Department of Chemical Engineering, Feng Chia University, Taichung 40724, Taiwan. b77315@hotmail.com.
authors.forename: Hsing-Yang
authors.initials: HY
authors.lastname: Tsai
authors.affiliation: Department of Chemical Engineering, Feng Chia University, Taichung 40724, Taiwan. a1981207@hotmail.com.
authors.forename: Che-Wei
authors.initials: CW
authors.lastname: Chang
authors.affiliation: Department of Chemical Engineering, Feng Chia University, Taichung 40724, Taiwan. kyuchen@fcu.edu.tw.
authors.forename: Kew-Yu
authors.initials: KY
authors.lastname: Chen
mesh_terms: D000042:Absorption; D020650:Combinatorial Chemistry Techniques; D007094:Imides / Q000138:chemical synthesis / Q000737:chemistry*; D007536:Isomerism; D008958:Models, Molecular; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010569:Perylene / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D007094:Imides; C510697:perylene bisimide; D010569:Perylene