Perylene Monoimide Research Articles

Perylene derivatives as a fluorescent probe for sensing of amines in solution

Amines play an important role in many physiological processes in living organisms. The present study explores the use of perylene diimide (PDI) and perylene monoimide (PMI) for the detection of common amines in solution. A systematic investigation using primary, secondary and tertiary amines as electron donors and perylene derivatives as electron acceptors is carried out in solution to understand the molecular interactions. Results from steady-state luminescence spectroscopy suggested that the PDI and PMI interact with the amine derivatives in the excited state, which led to photoinduced electron transfer and fluorescence quenching. Stern-Volmer plots were used to understand the quenching behavior of perylene derivatives in presence of various amines. The bimolecular rate constants of the dynamic quenching have been deduced for PDI, the values are in the range of 1.8 × 109 M−1s−1 for primary amines, 8 × 109 M−1s−1 for tertiary amines and 2.2 × 1010 M−1s−1 for aniline. Similar quenching rate constants for primary, secondary and tertiary amines were also observed for PMI. PDI showed higher selectivity for bulky hydrophobic amines over linear primary amines in solution. Such interactions could be investigated further to understand the response of perylene based sensors for amines.

Water-Soluble NIR-Absorbing Rylene Chromophores for Selective Staining of Cellular Organelles.

Biocompatible organic dyes emitting in the near-infrared are highly desirable in fluorescence imaging techniques. Herein we report a synthetic approach for building novel small peri-guanidine-fused naphthalene monoimide and perylene monoimide chromophores. The presented structures possess near-infrared absorption and emission, high photostability, and good water solubility. After a fast cellular uptake, they selectively stain mitochondria with a low background in live and fixed cells. They can be additionally modified in a one-step reaction with functional groups for covalent labeling of proteins. The low cytotoxicity allows a long time exposure of live cells to the dyes without the necessity of washing. Successful application in localization super-resolution microscopy was demonstrated in phosphate-buffered saline without any reducing or oxidizing additives.

Morphology Tuning of Self-Assembled Perylene Monoimide from Nanoparticles to Colloidosomes with Enhanced Excimeric NIR Emission for Bioimaging

Organic near-infrared (NIR) fluorescent probes have been recognized as an emerging class of materials exhibiting a great potential in advanced bioanalytical applications. However, synthesizing such organic probes that could simultaneously work in the NIR spectral range and have large Stokes shift, high stability in biological systems, and high photostability have been proven challenging. In this work, aggregation induced excimeric NIR emission in aqueous media was observed from a suitably substituted perylene monoimide (PeIm) dye. Controlled entrapment of the dye into pluronic F127 micellar system to preserve its monomeric green emission in aqueous media was also established. The aggregation process of the PeIm dye to form organic nanoparticles (NPs) was evaluated experimentally by the means of transmission electron microscope imaging as well as theoretically by the molecular dynamics simulation studies. Tuning the morphology along with the formation of colloidosomes by the controlled self-aggregation of PeIm NPs in aqueous suspension was demonstrated successfully. Finally, both excimeric and monomeric emissive PeIm NPs as well as PeIm colloidosomes were employed for the bioimaging in vitro.

Lamellar Peptide-Cadmium-Doped Zinc Oxide Nanohybrids That Emit White Light.

A variety of hybrid nanostructures have been developed that emit white light. Two different white-light-emitting systems are reported. These are cadmium-doped zinc oxide nanosheets and complex lamellar nanostructures that consist of alternating inorganic cadmium-doped zinc oxide domains with the self-assembled aromatic-capped peptide BPI-FF-OH (BPI: benzo[ghi]perylene monoimide, F: d-phenylalanine). An electrochemical method is employed to synthesize cadmium-doped zinc oxide nanosheets and lamellar organic/cadmium-doped zinc oxide nanoflakes on a gallium-doped ZnO/p-Si (111) substrate. External structural features and internal structural ordering of wurtzite cadmium-doped zinc oxide and lamellar organic/cadmium-doped zinc oxide nanohybrids are characterized by small-angle X-ray scattering, XRD, field-emission SEM, energy-dispersive X-ray spectroscopy, secondary-ion mass spectrometry, ellipsometry, and photoluminescence spectroscopy. Cadmium-doped zinc oxide nanosheets and lamellar organic/cadmium-doped zinc oxide hybrids emit white light with a broad emission covering the visible spectrum from λ=415 to 700 nm. Characteristic white-light emissions of both materials were well characterized by photoluminescence studies. The white-light luminescence is attributed to cadmium doping in the zinc oxide crystal and the presence of the dipeptide-functionalized BPI fluorophore in the lamellar nanohybrid.

Synthesis and Properties of Alkoxy-Bridged Triphenylene and Perylene Monoimide Diesters Dyads

Columnar discotic liquid crystals have high charge carrier mobility, and donor-bridge-accepter-based supra-molecular compounds have photoinduced intramolecular electron transfer behavior. In order to make the organic materials possess these two performances, dyads composed of hexaalkoxy triphenylene unit and perylene monoimide diesters unit were prepared in this work. In the dyads, the flexible alkoxys were used as bridges, the triphenylene units having six electron-donating alkoxy tails acted as electron donors, and the perylene monoimide diesters units having four electron-withdrawing carbonyls acted as electron acceptors. Their structures were established by proton nuclear magnetic resonance (H NMR), infrared spectroscopy (IR), mass spectrometry (MS) and elemental analysis (EA). The photophysical properties were characterized by means of UV-Vis absorption spectroscopy and fluorescence spectroscopy. The results showed that in dilute dichloromethane solutions the absorbance strength of these dyads was the sum of that of their monomers, hexakishexyloxy triphenylene (HAT6) and N-hexyl-perylene monoimide dihexyl esters (PMD6), and not interfered by the length of flexible bridges. When excited at 475 nm, the strength of the fluorescence of the dyads decreased when the spacers shortened from dodecyloxy, decyloxy, hexyloxy to ethoxy groups. Actually, when the spacer was ethoxy group, the fluorescence of the dyad was almost quenched completely. This is attributed to the photoinduced electron transfer properties (PET) between the donor and acceptor units. When excited at 280 nm, the strength of the fluorescence of the triphenylene units also became weaker when the spacers shortened from dodecyloxy to ethanyloxy. At the same time, the strength of the fluorescence of the perylene units became stronger. This is attributed to energy transfer from the triphenylene unit to the perylene unit. In addition, their liquid crystalline properties have been studied by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The results demonstrated that when the spacers were decyloxy and dodecyloxy the dyads possessed columnar liquid crystal behavior in the heating cir-

New and Efficient Approach to the Versatile Building Block of 3,4-Perylenedicarboxylic Monoanhydride

By a controllable and stepwise strategy, we have efficiently synthesized 3,4-perylenedicarboxylic monoanhydride (PDCMA), an important pigment and a versatile building block, in a gram-scale preparation. The mild reaction conditions, high yields, and simple postprocessing of the routes make it suitable for lab preparation and industrial production, which successfully achieves the challenge to avoid harsh reaction conditions, low yields, and difficult purification. Furthermore, using PDCMA and brominated PDCMA as the starting materials, we have also efficiently synthesized many perylene monoimide dyes in high yields.

Tuning the Electron Acceptor in Phthalocyanine-Based Electron Donor-Acceptor Conjugates.

Zinc phthalocyanines (ZnPc) have been attached to the peri-position of a perylenemonoimide (PMI) and a perylenemonoanhydride (PMA), affording electron donor-acceptor conjugates 1 and 2, respectively. In addition, a perylene-monoimide-monoanhydride (PMIMA) has been connected to a ZnPc through its imido position to yield the ZnPc-PMIMA conjugate 10. The three conjugates have been studied for photoinduced electron transfer. For ZnPc-PMIMA 10, electron transfer occurs upon both ZnPc and PMIMA excitation, giving rise to a long-lived (340 ps) charge-separated state. For ZnPc-PMI 1 and ZnPc-PMA 2, stabilization of the radical ion pair states by using polar media is necessary. In THF, photoexcitation of either ZnPc or PMI/PMA produces charge-separated states with lifetimes of 375 and 163 ps, respectively.

Supramolecular Packing Controls H₂ Photocatalysis in Chromophore Amphiphile Hydrogels.

Light harvesting supramolecular assemblies are potentially useful structures as components of solar-to-fuel conversion materials. The development of these functional constructs requires an understanding of optimal packing modes for chromophores. We investigated here assembly in water and the photocatalytic function of perylene monoimide chromophore amphiphiles with different alkyl linker lengths separating their hydrophobic core and the hydrophilic carboxylate headgroup. We found that these chromophore amphiphiles (CAs) self-assemble into charged nanostructures of increasing aspect ratio as the linker length is increased. The addition of salt to screen the charged nanostructures induced the formation of hydrogels and led to internal crystallization within some of the nanostructures. For linker lengths up to seven methylenes, the CAs were found to pack into 2D crystalline unit cells within ribbon-shaped nanostructures, whereas the nine methylene CAs assembled into long nanofibers without crystalline molecular packing. At the same time, the different molecular packing arrangements after charge screening led to different absorbance spectra, despite the identical electronic properties of all PMI amphiphiles. While the crystalline CAs formed electronically coupled H-aggregates, only CAs with intermediate linker lengths showed evidence of high intermolecular orbital overlap. Photocatalytic hydrogen production using a nickel-based catalyst was observed in all hydrogels, with the highest turnovers observed for CA gels having intermediate linker lengths. We conclude that the improved photocatalytic performance of the hydrogels formed by supramolecular assemblies of the intermediate linker CA molecules likely arises from improved exciton splitting efficiencies due to their higher orbital overlap.

Fluorene-centered perylene monoimides as potential non-fullerene acceptor in organic solar cells

A fluorene-centered perylene monoimide dimer, PMI-F-PMI with a partly non-coplanar configuration has been developed as a potential non-fullerene acceptor for organic solar cells (OSCs). The optimum power conversion efficiency (PCE) of the OSC based on PMI-F-PMI as acceptor and poly (3-hexyl thiophene) (P3HT) as donor is up to 2.30% after annealing at 150°C. The PCE of 2.30% is the highest value for the OSCs based on P3HT donor and non-fullerene acceptor lies in that PMI-F-PMI’s lowest unoccupied molecular orbital (LUMO) level around −3.50eV matches well with the donor P3HT to produce higher open-circuit voltage (Voc) of 0.98V. Meanwhile, PMI-F-PMI makes remarkable contribution to devices’ light absorption as the maximum EQE (30%) of the devices is at 512nm, same to the maximum absorption wavelength of PMI-F-PMI. The other favorable characteristics of PMI-F-PMI in bulk heterojunction (BHJ) active layers is proved through the photo current density measures, the relatively balanced electron–hole transport, and the smooth morphology with root mean square (RMS) value of 1.86nm. For these advantages, PMI-F-PMI overwhelms its sister PMI-F and parent PMI as an acceptor in BHJ solar cells.

Deriving binary phase diagrams for chromonic materials in water mixtures via fluorescence spectroscopy: cromolyn and water.

We report here the first example of a new and novel method of determining the binary temperature-composition phase diagram of a chromonic material in water using its intrinsic fluorescence. Disodium cromoglycate, or cromolyn, is an anti-allergy medicine representative of a class of compounds known as the chromonics. We have discovered that cromolyn's fluorescence is very sensitive to the polarity, hence structure, of the phase it exhibits. The fluorescence signal shifts its wavelength maximum and its shape depending on whether the cromolyn is a single phase or in coexisting phases. Since the signal due to individual phases can be identified, the fluorescence signal can reveal the temperature-induced transitions between single phase and phase coexistence regions. By studying such fluorescence data for different compositions, an isobaric temperature-composition phase diagram may be constructed. We present here a phase diagram derived from fluorescence studies that is in agreement with previous determinations using other techniques. Our results suggest that the binary phase diagrams of other intrinsically fluorescent chromonic materials, such as perylene monoimide and bisimide derivatives used in organic optoelectronic devices, solar cells, and light-emitting diodes, can be studied in water using an analogous fluorescence approach.

Supramolecular assembly of dipeptide functionalized benzo[ghi]perylene monoimide directs white light emission via donor–acceptor interactions

Optical and self-assembly nature of an aromatic dipeptide Phe-Phe (FF) functionalized benzo[ghi]perylene monoimide (BPI) are studied. Acceptor BPI-FF-OMe molecule shows white light emission upon energy transfer from donor pyrenebutyric acid molecule.

Synthesis and use of “clickable” bay-region tetrasubstituted perylene tetracarboxylic tetraesters and a perylene monoimide diester as energy acceptors

Novel perylene derivatives are ready to be used as functional energy acceptors in light-harvesting systems.

Design, synthesis and photoswitching of broad-spectrum fluorescent hexaarylbiimidazoles

A series of novel hexaarylbiimidazole (HABI)-containing fluorophores with broad-spectrum emissions ranging from blue, green and red emissions, have been designed and synthesized. Their photochromism and fluorescence switching properties are investigated by UV-Vis absorption and fluorescence spectra in solutions and PMMA films. By connecting carbazole (Cz), naphthalimide (NI) and perylene-mono-imide (PMI) to HABI with a spacer, three molecular photoswitches with broad-spectrum fluorescence varying from deep blue (Cz–O–HABI, λem = 390 nm, ΦF = 0.27), green (NI–O–HABI, λem = 490 nm, ΦF = 0.25) to far red (PMI–O–HABI, λem = 650 nm, ΦF = 0.25) have been obtained. The “ON”/“OFF” ratios are calculated to be about 8.9, 8.0 and 3.7 (calculated from FL spectra) for Cz–O–HABI, NI–O–HABI and PMI–O–HABI, respectively. Such a series of photoswitchable fluorophores constitute prototypes of a photochromic molecular library in which fluorescence resonance energy transfer can be reversibly modulated by an external stimulus, namely, UV light.

Benzo[ghi]perylene monoimide based photosensitive lamellar Cd-doped ZnO nanohybrids

Lamellar hybrid inorganic/organic nanostructures comprising of alternating layers of benzo[ghi]perylene monoimide and Cd-doped ZnO called BPyM/CZO nanohybrids have been synthesized electrochemically on Ga-doped ZnO/Si. In order to study the effect of organic surfactant, inorganic CZO nanorods have also been electrochemically synthesized. The role of annealing and organic surfactant on morphology, structure, composition and opto-electronic properties is analyzed. The nanohybrids and nanorods are c-axis oriented preferentially with their (002) direction perpendicular to the substrate surface. Annealed BPyM/CZO nanohybrids show visible orange photoluminescence emission while unannealed nanohybrids and inorganic CZO nanorods emit white emission at room temperature. The annealed nanohybrids and inorganic nanorods tend to follow the Varshni equation with temperature variation from 80 K to 300 K. Spectroscopic ellipsometry reveals the thickness, refractive index and band gap of the nanostructures. Annealing tends to expand the band gap by 50 meV in the case of inorganic CZO nanorods, but shrinks the band gap by 20 meV for BPyM/CZO nanohybrids. Temperature dependent photosensitivity measurements reveal that BPyM/CZO nanohybrids are highly photosensitive, ∼8 fold and ∼4 fold higher than inorganic CZO nanorods at 80 K and 300 K, respectively. The studies indicate that BPyM/CZO nanohybrids hold potential as photosensors.

Hierarchical supramolecular assembly of sterically demanding π-systems by conjugation with oligoprolines.

Self-assembly from flexible worm-like threads via bundles of rigid fibers to nanosheets and nanotubes was achieved by covalent conjugation of perylene monoimide (PMI) chromophores with oligoprolines of increasing length. Whereas the chromophoric π-system and the peptidic building block do not self-aggregate, the covalent conjugates furnish well-ordered supramolecular structures with a common wall/fiber thickness. Their morphology is controlled by the number of repeat units and can be tuned by seemingly subtle structural modifications.

Hierarchical Supramolecular Assembly of Sterically Demanding π‐Systems by Conjugation with Oligoprolines

AbstractSelf‐assembly from flexible worm‐like threads via bundles of rigid fibers to nanosheets and nanotubes was achieved by covalent conjugation of perylene monoimide (PMI) chromophores with oligoprolines of increasing length. Whereas the chromophoric π‐system and the peptidic building block do not self‐aggregate, the covalent conjugates furnish well‐ordered supramolecular structures with a common wall/fiber thickness. Their morphology is controlled by the number of repeat units and can be tuned by seemingly subtle structural modifications.

Self-assembling hydrogel scaffolds for photocatalytic hydrogen production.

Integration into a soft material of all the molecular components necessary to generate storable fuels is an interesting target in supramolecular chemistry. The concept is inspired by the internal structure of photosynthetic organelles, such as plant chloroplasts, which colocalize molecules involved in light absorption, charge transport and catalysis to create chemical bonds using light energy. We report here on the light-driven production of hydrogen inside a hydrogel scaffold built by the supramolecular self-assembly of a perylene monoimide amphiphile. The charged ribbons formed can electrostatically attract a nickel-based catalyst, and electrolyte screening promotes gelation. We found the emergent phenomenon that screening by the catalyst or the electrolytes led to two-dimensional crystallization of the chromophore assemblies and enhanced the electronic coupling among the molecules. Photocatalytic production of hydrogen is observed in the three-dimensional environment of the hydrogel scaffold and the material is easily placed on surfaces or in the pores of solid supports.

Synthesis and characterization of organic dyes with various electron-accepting substituents for p-type dye-sensitized solar cells.

Four new donor-π-acceptor dyes differing in their acceptor group have been synthesized and employed as model systems to study the influence of the acceptor groups on the photophysical properties and in NiO-based p-type dye-sensitized solar cells. UV/Vis absorption spectra showed a broad range of absorption coverage with maxima between 331 and 653 nm. Redox potentials as well as HOMO and LUMO energies of the dyes were determined from cyclic voltammetry measurements and evaluated concerning their potential use as sensitizers in p-type dye-sensitized solar cells (p-DSCs). Quantum-chemical density functional theory calculations gave further insight into the frontier orbital distributions, which are relevant for the electronic processes in p-DSCs. In p-DSCs using an iodide/triiodide-based electrolyte, the polycyclic 9,10-dicyano-acenaphtho[1,2-b]quinoxaline (DCANQ) acceptor-containing dye gave the highest power conversion efficiency of 0.08%, which is comparable to that obtained with the perylenemonoimide (PMI)-containing dye. Interestingly, devices containing the DCANQ-based dye achieve a higher V(OC) of 163 mV compared to 158 mV for the PMI-containing dye. The result was further confirmed by impedance spectroscopic analysis showing higher recombination resistance and thus a lower recombination rate for devices containing the DCANQ dye than for PMI dye-based devices. However, the use of the strong electron-accepting tricyanofurane (TCF) group played a negative role in the device performance, yielding an efficiency of only 0.01% due to a low-lying LUMO energy level, thus resulting in an insufficient driving force for efficient dye regeneration. The results demonstrate that a careful molecular design with a proper choice of the acceptor unit is essential for development of sensitizers for p-DSCs.

Electrical modulus and dielectric spectroscopy behavior of spin coated perylene-monoimide semiconductor films

Perylene-monoimide (PMI) semiconductor films produced by spin coating were investigated for use in electronic and optoelectronic devices. We provide an electric modulus and dielectric spectroscopy study on perylene-monoimide between 30kHz and 1MHz and at the various biases (0.11–0.59V with steps 0.02V). The real dielectric constant (ε′), imaginary dielectric constant (ε″), loss tangent (tanδ), ac conductivity (σac), real (M′) and imaginary electric modulus (M″) values of perylene-monoimide thin film were determined. It is observed that the ε′ and ε″ have a high value at lower frequencies. At the same time, the M″ versus frequency curve of the sample has a peak at lower frequncies and at all voltage values. This peak is attributed to the dielectric relaxation. The variation of Cole–Cole plots of the device presents that there is one relaxation.

Para-Quinodimethane-bridged perylene dimers and pericondensed quaterrylenes: the effect of the fusion mode on the ground states and physical properties.

Polycyclic hydrocarbon compounds with a singlet biradical ground state show unique physical properties and promising material applications; therefore, it is important to understand the fundamental structure/biradical character/physical properties relationships. In this study, para-quinodimethane (p-QDM)-bridged quinoidal perylene dimers 4 and 5 with different fusion modes and their corresponding aromatic counterparts, the pericondensed quaterrylenes 6 and 7, were synthesized. Their ground-state electronic structures and physical properties were studied by using various experiments assisted with DFT calculations. The proaromatic p-QDM-bridged perylene monoimide dimer 4 has a singlet biradical ground state with a small singlet/triplet energy gap (-2.97 kcal mol(-1)), whereas the antiaromatic s-indacene-bridged N-annulated perylene dimer 5 exists as a closed-shell quinoid with an obvious intramolecular charge-transfer character. Both of these dimers showed shorter singlet excited-state lifetimes, larger two-photon-absorption cross sections, and smaller energy gaps than the corresponding aromatic quaterrylene derivatives 6 and 7, respectively. Our studies revealed how the fusion mode and aromaticity affect the ground state and, consequently, the photophysical properties and electronic properties of a series of extended polycyclic hydrocarbon compounds.