Diaryl‐Substituted Perylene Bis(imides): Synthesis, Separation, Characterization and Comparison of Electrochemical and Optical Properties of 1,7‐ and 1,6‐Regioisomer

Abstract

A series of diaryl‐substituted perylene bis(imides) (PBIs) containing electron‐donating and ‐withdrawing aryl groups in the bay region (1‐, 6‐, 7‐ and/or 12‐positions of the perylene core) were synthesized by Suzuki coupling reaction. The corresponding regioisomers, namely, 1,7‐ and 1,6‐regioisomer, were separated from the mixture by conventional column chromatography without any need of recrystallization. All the individual regioisomers were fully characterized by 1H NMR and HRMS spectroscopy. The compounds were studied by optical spectroscopy and electrochemical techniques. The optical and electrochemical properties of 1,7‐regioisomer are slightly different from the 1,6‐regioisomer of the respective diaryl‐PBI. Significant redshift and broadening of the absorption and emission maxima were observed in all synthesized PBIs depending upon the electronic nature of the attached aryl group. This is very first time such large series of 1,6‐diarylperylenetetracarboxydiimides with their corresponding 1,7‐regioisomers were synthesized, separated, characterized and studied in detail.

Core Perylene Diimide Designs via Direct Bay‐ and ortho‐(Poly)trifluoromethylation: Synthesis, Isolation, X‐ray Structures, Optical and Electronic Properties

“…The imide group has a minimal effect on the absorption and emission spectra because of HOMO and LUMO orbitals nodes at the imide position 26. All 1,6 isomers exhibited larger Stokes shifts than the corresponding 1,7 isomers, which is consistent with other PDI series 12,27. Absorption and emission spectra broadening for 1,6 isomers with respect to corresponding 1,7 isomers has been observed in some derivatives,21a,28 but was not always the case with the isomeric pairs 29…”

“…The lifetimes of core‐modified PDIs are all longer than PDI(Bu) and the lifetimes of 1,6 derivatives are all longer than the 1,7 derivatives. Conversely, in a series of diaryl‐substituted PDIs, the 1,7 isomers had longer lifetimes than corresponding 1,6 isomers 30. In another study, PDI(C 8 H 17 )‐1,6‐[2,4‐bis( t Bu)‐Phenyl] 2 had a longer lifetime than the 1,7 isomer in three different solvents by ca.…”

Synthesis and Self‐Assembly of Bay‐Substituted Perylene Diimide Gemini‐Type Surfactants as Off‐On Fluorescent Probes for Lipid Bilayers

“…[33,37] Substitution of PDIs at the bay positioni s, however,s ynthetically demanding, involves halogenation reactions, and predominantly four-fold bay-substituted PDIs have been reported. [35,[38][39][40][41][42][43] Partly substituted 1,6-and 1,7-regioisomers, commonly as mixtures, [44][45][46][47][48] have also been synthesised, [49,50] while 1,12-bay-sub-stitutedP DIs have been rarely reported. The latter are interesting because the distortion of the perylene ring system by the 1,12-substitution will strongly alter the optical properties of the compound, comparable to their corresponding tetrasubstituted PDIs, while solubility and self-assembly properties will be different.…”

Arylphosphonylation and Arylazidation of Activated Alkenes

“…Thus, C–N or C–O bonds have been introduced by nucleophilic substitution with amines or alcohols 8,11,21. Organometallic reactions such as the Suzuki–Miyaura40 or the Sonogashira reaction were used to form C–C bonds in these positions. However, completing the corresponding reactions in all four bay positions has proved to be much more demanding.…”