Tuning the photodriven electron transport within the columnar perylenediimide stacks by changing the π-extent of the electron donors

Abstract

Photodriven electron-transport properties of the self-assemblies of N,N'-di(2-(trimethylammoniumiodide)ethylene)perylenediimide stacks (TAIPDI)(n) with three electron donors, disodium 4,4'-bis(2-sulfonatostyryl)biphenyl (BSSBP, stilbene-420), sodium 9,10-dimethoxyanthracene-2-sulfonate (DANS) and disodium 6-amino-1,3-naphthalenedisulfonate (ANADS) have been studied in water. These electron donors vary in their π-extent to adjust the electronic coupling and the distance with the PDI stacks. Possessing the largest π-extent, BSSBP has strong π-π interactions as well as ionic interactions with (TAIPDI)(n). Instead of π-stacking with TAIPDI planes, DANS and ANADS, with a relatively small π-extent, are embedded in the side chains of TAIPDIs via ionic interactions, resulting in a distance increment from the aromatic TAIPDI cores. After excitation, the BSSBP-(TAIPDI)(n) system exhibits fast charge separation (0.70 ps) and relatively slow charge recombination (485 ps) due to intermolecular electron delocalization along the TAIPDI stacks. On the other hand, charge separation in DANS-(TAIPDI)(n) and ANADS-(TAIPDI)(n) occurs within 1.5 and 1.6 ns, respectively, calculated from the quenching of singlet excited states. The lifetimes of charge-separated states are determined to be 44 and 96 μs, at least 10(5) times slower than that of BSSBP-(TAIPDI)(n) due to remarkably improved electron transport throughout the (TAIPDI)(n).

Energy and Electron Transfer of One-Dimensional Nanomaterials of Perylenediimides

“…The drawbacks due to tight stacking in the host-guest system of 1 and 10 were overcome by introducing a reasonable gap between the stacks of 1 and electron donor 26 and 27 with limited concentrations. 69 Small π-extent of 26 and 27 decreased the π-π interactions with π-stacks of PDI. 26 and 27 were embedded in the side chains of PDIs via ionic interactions, resulting in the increment of charge separation distances.…”

Enhancement of Photodriven Charge Separation by Conformational and Intermolecular Adaptations of an Anthracene–Perylenediimide–Anthracene Triad to an Aqueous Environment

“…Previously, we have examined the photodynamics of the 1D PDI nanostructures in the presence of electron donors in various self-assembly models with changing the electron-transfer distance in aqueous media. − Ionic and π–π interactions were employed for the self-assembly of PDI stacks with the donor moieties. We have proposed that fast charge recombination can be overcome through an intermolecular electron migration mechanism throughout the columnar PDI stacks and a fair distance between PDI stacks and the donor moieties, which lessens the electronic coupling while enabling the exciton dissociation for charge separation before being wasted by other processes (i.e., nonradiative decay and energy transfer) …”

The impact of trans/cis photoisomerization on photoinduced electron transport between 4,4′-stilbenedicarboxylic acid and columnar perylenediimide aggregates in water

“…No isosbestic point was observed during the titration. In addition, the absorption peaks of 0-0 and 0-1 bands of (PDI-I) n red-shift to 548 and 509 nm, respectively, demonstrating the presence of ionic interactions between trans-SDBA and (PDI-I) n and the absence of efficient π−π interactions between them [12]. It is also worth noting that the 0-1 vibronic band of PDI at about 500 nm is still the largest absorption band in the absorption spectrum of PDI-I in the presence of equivalence trans-SDBA, which means that the faceto-face stacked structure of (PDI-I) n is not broken utterly by the trans-SDBA molecules.…”

“…In these supramolecular systems, electron donors and acceptors selfassemble into complexes, which offer the place for the PET process. Naturally, the rate and efficiency of PET process are determined by supramolecular interactions between donors and acceptors, such as weak intermolecular interactions [12][13][14] and/or hydrogen bonding [15] and/or ionic interactions [9], which affect the combination mode between donor and acceptor. Appropriate combination mode will result in effective overlap of the electron cloud between donor and acceptor and favor the PET process.…”