Chiral Perylene Diimides: Building Blocks for Ionic Self‐Assembly

Abstract

A chiral perylene diimide building block has been prepared based on an amine derivative of the amino acid l‐phenylalanine. Detailed studies were carried out into the self‐assembly behaviour of the material in solution and the solid state using UV/Vis, circular dichroism (CD) and fluorescence spectroscopy. For the charged building block BTPPP, the molecular chirality of the side chains is translated into the chiral supramolecular structure in the form of right‐handed helical aggregates in aqueous solution. Temperature‐dependent UV/Vis studies of BTPPP in aqueous solution showed that the self‐assembly behaviour of this dye can be well described by an isodesmic model in which aggregation occurs to generate short stacks in a reversible manner. Wide‐angle X‐ray diffraction studies (WXRD) revealed that this material self‐organises into aggregates with π–π stacking distances typical for π‐conjugated materials. TEM investigations revealed the formation of self‐assembled structures of low order and with no expression of chirality evident. Differential scanning calorimetry (DSC) and polarised optical microscopy (POM) were used to investigate the mesophase properties. Optical textures representative of columnar liquid–crystalline phases were observed for solvent‐annealed samples of BTPPP. The high solubility, tunable self‐assembly and chiral ordering of these materials demonstrate their potential as new molecular building blocks for use in the construction of chiro‐optical structures and devices.

1D Self‐Assembly and Ice Recrystallization Inhibition Activity of Antifreeze Glycopeptide‐Functionalized Perylene Bisimides

“…For PBI 1 in water, a bisignate Cotton effect was observed with a positive and negative maxima at 500 and 450 nm, respectively (Figure c and Figure S4). This signal is consistent with chiral excitonic coupling and the formation of right‐handed helical aggregates . The CD signal gradually diminished upon increasing acetonitrile content as the unimeric species predominated.…”

Non-equilibrium steady states in supramolecular polymerization

“…2e) that is due to right-handed P-helical stacking28293031. Interestingly, an inversion of the CD spectrum to a clear negative couplet was observed upon phosphorylation, pointing to left-handed M-helical polymers for p2-PDI (red line in Fig.…”

Living Supramolecular Polymerisation of Perylene Diimide Amphiphiles by Seeded Growth under Kinetic Control

“…The temperature‐dependent UV/Vis absorption spectra were deconvoluted in order to take into account the shoulder of the unimer peak at 525 nm interfering with the value for the aggregate peak at 556 nm (see Supporting Information for further details, Figure S23–S26). The degree of aggregation ( α ) was calculated by taking the intensity of the peak at 556 nm after deconvolution and normalising the data . A plot of degree of aggregation as a function of temperature produced a non‐sigmodal curve (Figure S26), indicative of a cooperative supramolecular polymerisation.…”

“…As the concentration of the samples was increased, the unimer peaks at 490 and 525 nm became broader and the aggregate peak at 556 nm increased in intensity. The degree of aggregation was taken as the intensity of the aggregate peak at 556 nm relative to the unimer peak at 525 nm, so that the intensity difference between samples due to concentration could be accounted for (Figure S27 b). Unimer peaks were detectable up to concentrations of 9.4×10 −5 m .…”