Energy and Electron Transfer of One-Dimensional Nanomaterials of Perylenediimides

Abstract

This review describes the photodriven energy-and electron-transfer processes of the columnar perylenediimide (PDI) nanostructures for efficient light-energy conversion by employing the self-assembly models. The charge separation and the directional charge transport of the oligomers, aggregates, and one-dimensional (1D) nanostructures of PDIs have been clarified by using time-resolved transient absorption techniques. Excited states, exciton migration, and excitation energy-transfer processes were examined in the first part. The second part involves the electron hopping, photodriven electron transfer and transport events taking place within the various PDI nanostructures.Unique light-harvesting and redox properties together with high chemical, thermal and photostability make perylenediimides (PDIs) the essential building blocks of energy and electron donor-acceptor systems. One important feature of PDI is its large π-plane enabling the π-π interactions for self-assembly. 1 PDIs can form one-dimensional (1D) nanostructures by supramolecular self-assembly in the solution as a low-cost, affordable bottom-up method. 2-4 The length of PDI nanofibrils can reach about 0.3 mm due to strong π-stacking in 'poor' solvents. 5 Other than the solvophobic effects, 6-8 hydrogen bonding 9-12 and ionic interactions 13-15 assisting π-π interactions have been used to fabricate nanoscale materials of PDIs in one dimension. Coupled crystallization of PDI with proper polymer templates by solvent evaporation 16 and chemical-reaction mediated self-assembly in the solution 17,18 are the other convenient bottom-up methods for the fabrication of 1D nanofibers of PDI. The long axes of these 1D structures are feasible for long-range exciton diffusion when exposed to light 19,20 and for electron transport after an electron-transfer process from electron donors. 21,22 Such features of 1D nanostructures of PDI have led to various applications. For example, n-type semiconducting properties of PDI nanowires have been utilized in organic field effect transistors 23-25 and phototransistors. 26 Nanostructures of PDIs have also been widely used in the sensing applications for nitrobased explosives, 27 organic amines, 28 and nitrogen-based reducing agents. 29,30 Their photovoltaic properties have been also reported. 31,32 There have been many comprehensive reviews regarding the fabrication methods and the applications of 1D nanostructures of PDIs together with various organic materials, some of which are already referred in this review. [2][3][4]11 Besides these aspects, elucidation of the fundamental energy and electron-transfer events taking place within the PDI nanostructures is also of importance to improve the quality and efficiency of the current applications and to rationalize the future design of the related devices. This review will basically focus on the photoinduced energy-and electron-transfer processes occurring in the aggregates and nanostructures of PDIs, which mainly have 1D geometry. Photoinduced processes of supramolecular oligomeric an...

Self-Assembly of Perylene Imide Molecules into 1D Nanostructures: Methods, Morphologies, and Applications

“…14,21,26,29 On the contrary, bay-substitution often significantly disturbs the well-organized self-assembly of PDIs. 29 In many cases, steric effects imparted by bay substituents can lead to a twisting of the PDI plane, that is, a distortion of the π-systems from planarity, potentially increasing the solubility and restraining the crystal packing arrangement behavior induced by π−π stacking. 23 Note that the side-chain effect on the supramolecular selfassembly of PDIs is far from absolute.…”

“…14,21,26 In comparison with the individual molecules or bulk-phase materials, 1D nanostructures of PIs exhibit uniaxial optical and electronic properties along the 1D π−π stacking direction, which provides great potential for application in optoelectronic devices, especially at the nanoscale. 14,21,24,26,29 Research in the relevant fields has received increasing attention in recent years. 2,4,9,14,16,21,25−29 Although several excellent reviews have previously been published on the broader topics of molecular self-assembly including some PIs, 14,21,26,29 it still remains crucial to provide a deep, extensive review especially focused on various molecular designs of PIs.…”

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

“…Typically, PDI-I molecules self-assemble into aggregates (PDI-I) n in water with absorption bands at 534, 500, and 467 nm, which can be assigned to the 0-0, 0-1, and 0-2 vibronic bands of the first excited states, respectively [13]. Among these absorption bands, the 0-1 band has the largest intensity, which is a sign of the formation of Bface-to-faceŝ tacked PDI aggregates in solution [13,20,36]. The fluorescence spectrum of (PDI-I) n presents one broad band in the region of longer wavelength, which can be assigned to the Bexcimer-like^states due to the formation of Bface-to-faceŝ tacked structure [37,38].…”

“…Especially, the oneElectronic supplementary material The online version of this article (doi:10.1007/s00396-015-3639-z) contains supplementary material, which is available to authorized users. dimensional PDI assembly, which can provide a pathway for electron delocalization and have low reduction potential, is recognized as a good candidate of electron acceptors for PET process [20].…”

Broadband Light Harvesting and Fast Charge Separation in Ordered Self-Assemblies of Electron Donor–Acceptor-Functionalized Graphene Oxide Layers for Effective Solar Energy Conversion

“…17 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 Figure S1, in SI) and GO (E ox = 0.88 V vs SCE). 18,39 PDI has a first oneelectron reduction potential comparable to that of C 60 , 40 which is much stronger electron-14 acceptor than GO. 41,42 Apparently, GO surface acts as a passage for electrons rather than being a final electron donor or acceptor.…”