Mixed donor–acceptor charge-transfer stacks formed via hierarchical self-assembly of a non-covalent amphiphilic foldamer

Abstract

A non-covalent, amphiphilic foldamer design leads to an efficient charge-transfer complex between dipyrene (donor) and naphthalene diimide (acceptor) derivatives, which further self-assembles into one-dimensional nanofibers with an alternate (mixed) donor-acceptor arrangement.

Supramolecular complexation between chain-folding poly(ester-imide)s and polycyclic aromatics: a fractal-based pattern of NMR ring-current shielding

“…It is well established that complexation of certain polyimides by electron-rich aromatic units such as pyrene and perylene, via complementary π-π-stacking, leads to substantial upfield complexation shifts of 1 H NMR resonances associated with the diimide residues, as a result of magnetic ring-current shielding by the complexed aromatic unit. [8][9][10][11][12][13][14][15] Although the forces involved in complementary π-π-stacking remain a matter for discussion, it is clear that this type of supramolecular complexation is favoured by coplanarity of the diimide residues, as in PMDI and NDI, and strongly disfavoured by non-planar and/or sterically-hindered diimide units such as HFDI.…”

“…Charge-transfer absorptions resulting from polyimide complexation with these aromatic molecules produce strongly coloured solutionsdeep red for pyrene and an intense dark green for perylene. 11…”

“…This effect has also been discussed in other, related work on polymer chain-folding induced by π-π-stacking. [11][12][13][14] It has further been shown that additive, long range ring-current shielding by tweezer molecules bound further out along the chain increases the complexation shifts of NDI resonances, resulting in these shifts being highly sequence-dependent. 9 In addition, different tweezer-molecules were found to bind to different triplet-sequences, thereby producing a "frameshift" effect in the binding of longer sequences by multiple tweezermolecules.…”

Temporal switching of an amphiphilic self-assembly by a chemical fuel-driven conformational response

“…Herein we introduce a charge transfer 8 (CT) interaction governed amphiphilic foldamer 9 that exhibits temporal control over its switchable conformation and self-assembly by a bio-inspired chemical fuel-driven strategy. Our unique molecular design of the amphiphilic foldamer, PN–VN , consists of an electron donor (pyranine) connected through a flexible hydrophilic hexaethylene glycol connector to an electron acceptor (viologen), which is further attached to a hydrophobic tail endowing its amphiphilic nature ( Scheme 1a ).…”

Nanostructured Donor–Acceptor Self Assembly with Improved Photoconductivity

“…NMR spectra of the supramolecular polymer complex [UPBI-Py Poly(OPVM-OH)] 1.0 was recorded in CDCl3 and compared with that of the complex as shown inFigure 2-a,c (expanded region from 4.0 to 9.5 ppm). The proton NMR spectra showed the presence of unreacted methacrylate double bond in the polymer, but its intensity had reduced compared to the OPV aromatic protons.…”