How does the interplay between bromine substitution at bay area and bulky substituents at imide position influence the photophysical properties of perylene diimides?

Abstract

This article reports a comparative study on the photophysical properties of perylene diimides which caused by the interplay between bromine substitution at bay area and bulky substituents at imide position.

Strong Emission Enhancement in pH‐Responsive 2:2 Cucurbit[8]uril Complexes

“…Therefore, the strong fluorescence enhancement cannot be attributed solely to the prevention of TICT state formation, but is also caused by the combination of RIM and dimer formation inside the cucurbituril cavity. The relatively low quantum yield value of complex ( 6 + Cl − ) 2 @CB[8] 2 and especially the modest enhancement compared to the CB[7] complex ( ϕ =4 to 5 %) are due to quenching by the heavy‐atom effect of the bromo‐substituent in the dimeric structure …”

“…However,t he major effect is the RIM, that is, hindered rotations aroundt he aryl/aryl bonds caused by dimerizationi nside the cavity.T herefore, the strong fluorescence enhancement cannot be attributed solelyt ot he prevention of TICT state formation,b ut is also caused by the combination of RIM and dimer formationi nside the cucurbituril cavity.T he relativelyl ow quantum yield value of complex (6 + Cl À ) 2 @CB [8] 2 and especially the modest enhancement compared to the CB [7] complex (f = 4t o5%) are due to quenching by the heavy-atome ffect of the bromo-substituent in the dimericstructure. [26] The guest molecules can be furtherf unctionalized on the pyridine side by simple N-alkylation. As ar esult,t he pH switch is eliminated.…”

Concentration-dependent self-assembly structures of an amphiphilic perylene diimide with tri(ethylene glycol) substituents at bay positions

“…3 Shape, size, and intermolecular interactions of the individual building blocks are important factors which drive the selfassembly process toward their supramolecular architecture. [5][6][7][8][9] Self-assembly of amphiphilic molecules is usually conducted in the solution phase and is governed by weak non-covalent interactions, which is a fundamental process not only in nature but also in supra-molecular chemistry. 1 Despite many efforts, self-assembly of amphiphilic molecules to form complex functional architectures by multi-physical interaction (the synergistic effects of the p-p stacking, hydrophobic effect and the hydrogen bond interaction) represents still a very challenging and unsolved task.…”

Synthesis, Self-Assembly and Characterization of Tandem Triblock BPOSS-PDI-X Shape Amphiphiles

“…It is thus intriguing to further explore their self-assembly in solid state, especially in crystals. One would anticipate that dimers could also serve as the building block in solid state for further packing into crystals, just like that observed in BPOSS-PDI-BPOSS derivatives [46,50,67]. Quantum mechanics studies will also be greatly helpful to further understand the molecular interactions and connect the structural-property relationship [68].…”