Perylene Tetracarboxylic Acid Diimide Research Articles

Interaction of N,N'-Di(4-chlorophenyl)diimide 1,1'-Binaphtyl-4,4',5,5',8,8'-hexacarboxylic Acid with Thiourea Dioxide in Solution and Thin Film

The reactions of interaction of N,N'-di(4-chlorophenyl)diimide 1,1'-binaphtyl-4,4',5,5',8,8'-hexa-carboxylic acid (cubogen red) with thiourea dioxide in a water-alkaline solution and a Langmuir–Blodgett thin film, obtained on quartz and silicon substrates, have been investigated. Electron absorption spectroscopy have revealed that the reaction of reductive cyclization of cubogen with formation of perylenetetracarboxylic acid diimide derivatives occurs in a water-alkaline solution. At the same time, the interaction of thiourea dioxide with a cubogen thin film does not lead to the formation of cyclization products; nevertheless, it changes the film structure. One might suggest that soluble leuco forms of J aggregates are formed in this case, whereas H aggregates remain intact in the structure.

A novel turn-off fluorescent aptasensor for ampicillin detection based on perylenetetracarboxylic acid diimide and gold nanoparticles

Herein, a novel turn-off fluorescent aptasensor was developed for selective detection of ampicillin (AMP) at picomolar level based on 3,4,9,10-perylenetetracarboxylic acid diimide (PTCDI) as an affordable and low-cost fluorophore. This aptasensor was designed using aptamer, its complementary strand (CS) and gold nanoparticles (AuNPs). The principle of the sensing method is a decrease in the fluorescence intensity of PTCDI in the presence of free CS. Following the addition of AMP, Aptamer/CS-modified AuNPs releases CS and so, the fluorescence intensity of PTCDI is reduced. The designed analytical method indicated a good linear range from 100 pM to 1000 pM and a limit of detection (LOD) of 29.2 pM was obtained. Furthermore, the sensing strategy indicated satisfactory results for the detection of AMP in the spiked human serum samples. By changing the sequences of aptamer and its CS, the presented analytical approach can be easily applied for detection of other antibiotics.

Accurate First-Principles Calculation of the Vibronic Spectrum of Stacked Perylene Tetracarboxylic Acid Diimides.

π-stacked organic electronic materials are tunable light absorbers with many potential applications in optoelectronics. The optical properties of such molecules are highly dependent on the nature and energy of electron-hole pairs or excitons formed upon light absorption, which in turn are determined by intra- and intermolecular electronic and vibrational excitations. Here, we present a first-principles approach for describing the optical spectrum of stacked organic molecules with strong vibronic coupling. For stacked perylene tetracarboxylic acid diimides, we describe optical excitations by using the time-dependent density functional theory with a Franck-Condon Herzberg-Teller approximation of vibronic effects and validate our approach with comparison to experimental ultraviolet-visible (UV-vis) absorption measurements of solvated model systems. We determine that for larger macromolecules, unlike for single molecules, the sampling of the ground-state potential energy surface significantly influences the optical absorption spectrum. We account for this effect by applying our analysis to ∼100 structures extracted from equilibrated molecular dynamics simulations and averaging the optical spectrum over the entire ensemble. Additionally, we demonstrate that intermolecular electronic coupling within the stacks results in multiple low-energy electronically excited states that all contribute to the optical spectrum. This study provides a computationally feasible recipe for describing the spectroscopic properties of stacked organic chromophores via first-principles density functional theory.

From Dyestuff Chemistry to Cancer Theranostics: The Rise of Rylenecarboximides.

Fighting cancer with the means of chemistry remains a tremendous challenge and defines a pressing societal need. Compounds based on synthetic organic dyes have long been recognized as vital tools for cancer diagnosis and therapy (theranostics). Fluorescence and photoacoustic imaging of cancer as well as cancer treatment protocols such as photodynamic and photothermal therapy are all photobased technologies that require chromophores. However, a serious drawback of most chromophoric molecules is photobleaching over the course of their use in biological environments, which severely compromises the desired theranostic effects. At this point, rylenecarboximide (RI) dyes with ultrahigh photostability hold enormous promise. RI stands for a homologous series of dyes consisting of an aromatic core and carboximide auxochromic groups. They possess high molar extinction coefficients and finely tunable photophysical properties. RIs such as perylenebiscarboxylic acid monoimide (PMI), perylenetetracarboxylic acid diimide (PDI), terrylenetetracarboxylic acid diimide (TDI), and quaterrylene tetracarboxylic acid diimide (QDI) have attracted great scientific attention as colorants, components of organic photovoltaics and organic field-effect transistors, as well as tools for biological applications. PDI has appeared as one of the most widely studied RI dyes for fluorescence bioimaging. Our recent breakthroughs including chemotherapy with PDI-based DNA intercalators and photothermal therapy guided by photoacoustic imaging using PDI, TDI, or QDI, define urgent needs for further scientific research and clinical translation. In this Account, we tackle the relationship between chemical structures and photophysical and pharmacologic properties of RIs aiming at new contrast and anticancer agents, which then lay the ground for further biomedical applications. First, we introduce the design concepts for RIs with a focus on their structure-property relationships. Chemical structure has an enormous impact on the fluorescent, chemotoxic, photodynamic, and photothermal performance of RIs. Next, based on the resulting performance criteria, we employ RIs for fluorescence and photoacoustic cancer imaging as well as cancer therapies. When carrying electron donating substituents, PDIs and PMIs possess high fluorescence quantum yield and red-shifted emission which qualifies them for use in cancer fluorescence imaging. Also, some fluorescent PDIs are combined with chemodrugs or developed into DNA intercalators for chemotherapy. PDI-based photosensitizers are prepared by "heavy atom" substitution, showing potential for photodynamic therapy. Further, photothermal agents using PDI, TDI, and QDI with near-infrared absorption and excellent photothermal conversion efficiency offer high promise in photothermal cancer therapy monitored by photoacoustic imaging. Finally, looking jointly at the outstanding properties of RIs and the demands of current biomedicine, we offer an outlook toward further modifications of RIs as a powerful and practical platform for advanced cancer theranostics as well as treatment of other diseases.

The enrichment of photo-catalysis via self-assembly perylenetetracarboxylic acid diimide polymer nanostructures incorporating TiO2 nano-particles

This paper reports that hybrid titanium dioxide (TiO2) packaged self-assembly perylenetetracarboxylic acid diimide (PTCDI) by self-assembly. These were synthesized through simple mechanical milling that has great photocatalytic performance under visible light. The PTCDI@TiO2 composite had high activity for the degradation of phenol and 2,4-dichlorophenol, which were 2.3 and 3.2 times of the monomer PTCDI, respectively. After three cycles, the activity of the composite catalyst remained at 70%. Further analysis showed that the photocatalytic activity and stability are mainly due to the enhancement of the charge mobility by the π-π conjugated structure in PTCDI. Moreover, the good energy level matching between PTCDI and TiO2 helps to separate the electron-hole, thus improving the photocatalytic performance of the composite. The origin of photocatalytic activity was greatly improved due to holes and O2−, which was mainly attributed to the strong interaction between PTCDI and TiO2.

Work function and temperature dependence of electron tunneling through an N-type perylene diimide molecular junction with isocyanide surface linkers.

Conducting probe atomic force microscopy (CP-AFM) was employed to examine electron tunneling in self-assembled monolayer (SAM) junctions. A 2.3 nm long perylene tetracarboxylic acid diimide (PDI) acceptor molecule equipped with isocyanide linker groups was synthesized, adsorbed onto Ag, Au and Pt substrates, and the current-voltage (I-V) properties were measured by CP-AFM. The dependence of the low-bias resistance (R) on contact work function indicates that transport is LUMO-assisted ('n-type behavior'). A single-level tunneling model combined with transition voltage spectroscopy (TVS) was employed to analyze the experimental I-V curves and to extract the effective LUMO position εl = ELUMO - EF and the effective electronic coupling (Γ) between the PDI redox core and the contacts. This analysis revealed a strong Fermi level (EF) pinning effect in all the junctions, likely due to interface dipoles that significantly increased with increasing contact work function, as revealed by scanning Kelvin probe microscopy (SKPM). Furthermore, the temperature (T) dependence of R was found to be substantial. For Pt/Pt junctions, R varied more than two orders of magnitude in the range 248 K < T < 338 K. Importantly, the R(T) data are consistent with a single step electron tunneling mechanism and allow independent determination of εl, giving values compatible with estimates of εl based on analysis of the full I-V data. Theoretical analysis revealed a general criterion to unambiguously rule out a two-step transport mechanism: namely, if measured resistance data exhibit a pronounced Arrhenius-type temperature dependence, a two-step electron transfer scenario should be excluded in cases where the activation energy depends on contact metallurgy. Overall, our results indicate (1) the generality of the Fermi level pinning phenomenon in molecular junctions, (2) the utility of employing the single level tunneling model for determining essential electronic structure parameters (εl and Γ), and (3) the importance of changing the nature of the contacts to verify transport mechanisms.

Spectroscopic, electrochemical and photovoltaic properties of Pt(ii) and Pd(ii) complexes of a chelating 1,10-phenanthroline appended perylene diimide.

In this study, a bis-chelating bridging perylene diimide ditopic ligand, namely N,N'-di(1,10-phenanthroline)-1,6,7,12-tetrakis-(4-methoxyphenoxy)perylene tetracarboxylic acid diimide (1), was synthesized and characterized. Further reactions of 1 with d8 metal ions such as Pt(ii) and Pd(ii) having preferential square-planar geometry afforded the novel triads [(Cl2)M(ii)-(1)-M(ii)(Cl2)] where M(ii) = Pt(ii) (2), and Pd(ii) (3), respectively. The isolated triads and the key precursor were fully characterized by FT-IR, 1D-NMR (1H NMR and 13C DEPT NMR), 2D-NMR (1H-1H COSY, 1H-13C HSQC, 1H-13C HMBC), MALDI-TOF mass and UV/Vis spectroscopy. The electrochemical properties of 1, 2 and 3 were investigated by cyclic voltammetry as well as in situ spectroelectrochemistry and also in situ electrocolorimetric measurements. These compounds were shown to exhibit net colour changes suitable for electrochromic applications. The compounds exhibited remarkably narrow HOMO-LUMO gaps, leading to their ease of reduction at low negative potentials. More importantly, dye-sensitized solar cells (DSSCs) were also fabricated using 1-3 to clarify the potential use of these complexes as a sensitizer. Analysis of the experimental data indicated that 2 has good potential as a sensitizer material for DSSCs.

Ultrasensitive detection of lead(II) using a turn-on probe based on the use of an aptamer and a water-soluble fluorescent perylene probe

The authors describe an ultra-sensitive approach for the determination of lead(II) by using a lead-specific aptamer and a fluorophore derived from perylenetetracarboxylic acid diimide (PTCDI). The fluorescence of PTCDI, with excitation/emission peaks at 494/543 nm, is quenched by the aptamer but restored if the aptamer binds lead(II). A detection scheme has been worked out that has a 0.1 ng·mL−1limit of detection and a dynamic range that extends from 0.1 ng·mL−1 to 10 μg·mL−1. The assay also demonstrates high selectivity for lead ions over nine other ions due to the aptamer’s high specificity. The method shows a average recovery of 77.2–93.4% with an RSD of less than 3% in water samples.

Short-Range π–π Stacking Assembly on P25 TiO2 Nanoparticles for Enhanced Visible-Light Photocatalysis

Utilization of the renewable solar fuel based on a perylenetetracarboxylic acid diimide (PTCDI)–semiconductor composite represents an effective method to solve the energy crisis; however, most applications have focused on dye sensitization of the monomolecular layer. Here the synergy effect of PTCDI self-assembly and P25 nanoparticles (NPs) has been elucidated systematically from the PTCDI stacking structure on P25 NP and electron transfer (ET) mode, for which the visible-light photocatalytic activity of PTCDI self-assembly through the assistance of P25 has been acquired and enhanced, even up to 7 times with the addition of EDTA. It has been found that self-assembly of PTCDI nanowires (NWs) as building blocks has been reconstructed on P25 NP via arrangement of short-range π–π stacking that is important for high photocatalytic activity. We inferred that the indentation plays a key role in the formation of the short-range π–π stacking mode on the basis of the results of XRD, photoluminescence, transient dec...

Shift of absorption energy during thin dye film growth: interpretation by geometric models of the growth morphology

We measure absorption spectra of two different perylene molecules in thin films with thicknesses varied between 1 and 30nm physical vapor deposited on glass substrates. Atomic force microscopy (reveals the formation of crystallized needles for N, N`-dimethyl perylene tetracarboxylic acid diimide and amorphous round-shaped islands for 1,6,7,12-tetrachloro-N,N`-dimethyl perylene tetracarboxylic. For both molecules, a spectral shift of the lowest energy transition to lower energies was observed with increasing film thickness. Common models taking electric fields, electronic coupling or exciton confinement into account cannot completely describe the observed spectral shift. Here we show that the experimental values can be fitted with an advanced layering model based on the energetic difference between bulk and interface/surface materials. In contrast to the known simple d−1 model, which describes the energetic shift for the special case of a layer-by-layer growth, we extend this idea to other film morphologies.

A simple and sensitive label-free fluorescent approach for protein detection based on a Perylene probe and aptamer

Highly sensitive detection of proteins is of great importance for effective clinical diagnosis and biomedical research. However, so far most detection methods rely on antibody-based immunoassays and are usually laborious and time-consuming with poor sensitivity. Here, we developed a simple and ultra-sensitive method to detect a biomarker protein–thrombin by taking advantage of the fluorescent probe Perylene tetracarboxylic acid diimide (PTCDI) derivatives and thrombin aptamer. The water-soluble dye PTCDI shows strong fluorescence in buffer solution for the existence of free dye monomer, but becomes weak after aggregation through self-assembly on nucleic acid aptamer. In the presence of thrombin, it specifically binds to thrombin aptamer which causes the conformational transition between aptamer and PTCDI and results in a significant fluorescence recovery. The results showed that as low as 40pM of thrombin could be detected by this method. The high sensitivity of the developed sensing system mainly attributes to the ultra-sensitivity of the fluorescence intensity changes of PTCDI. With the specificity of aptamer, the assay exhibited high selectivity for thrombin against three other proteins (bovine serum albumin, lysozyme, mouse IgG) and 1% diluted fetal bovine serum. The detection method might be extended to sensitive detection of a variety of proteins for its advantages of isothermal conditions required, simple and rapid without multiple separation and washing steps.

Perylene derivative-bridged Au-graphene nanohybrid for label-free HpDNA biosensor.

Along with the challenges of wet-chemically preparing graphene-based nanohybrids, for example easy aggregation, low-stability in solution environment and insufficient loading amount, here we report the preparation and application of a type of π-conjugated molecule, perylenetetracarboxylic acid di-imide (PDI)-functionalized graphene material with high density of gold nanoparticles (AuNPs). In this nanohybrid, the PDI molecule comprises five-connected benzene rings and positively charged terminals composed of two symmetrical imidazole rings and amine groups, which offers the intrinsic driving force for π-π interactions with graphene and also serves as the active sites for immobilization of AuNPs. Transmission electron microscopy results demonstrated that AuNPs were uniformly dispersed and densely covered the PDI-functionalized graphene compared to the control experiment without PDI. To prove its biological application, the Au-PDI-graphene nanohybrid was chosen as a sensing material for fabricating a label-free electrochemical impedance hairpin DNA (hpDNA) biosensor for detection of human immunodeficiency virus 1 gene. When hpDNA was hybridized, it exhibited a sensitive electrochemical impedance variation on an Au-PDI-graphene modified electrode. This fabricated hpDNA biosensor reveals a wide linear detection range and a relatively low detection limit. Thanks to its high stability and efficient electrochemical impedance sensitivity, this nanohybrid would offer a broad range of possible DNA sequences for specific applications in biodiagnostics and bionanotechnology.

New organic–inorganic hybrid materials based on perylene diimide–polyhedral oligomeric silsesquioxane dyes with reduced quenching of the emission in the solid state

Abstract Solid state luminescent materials are the subject of ever growing interest both from a scientific and a technological point of view because high-tech applications of light emitting materials very often require their use in the condensed phase. Aggregation caused quenching processes however represent an obstacle to the development of most luminogens in the condensed phase. This is why particularly fascinating are those materials showing high emission intensity in the solid state. Aggregation caused quenching is particularly detrimental for π-extended polycyclic aromatic hydrocarbons, for example perylene tetracarboxylic acid diimides which are characterized by a near-unity fluorescence quantum yield in solution but are far less emissive in the solid state. Here we report on the easy preparation and on the optical investigation of perylene tetracarboxylic acid diimide derivatives linked to the inorganic cage of polyhedral oligomeric silsesquioxanes. These new hybrid perylene diimide–polyhedral oligomeric silsesquioxane dyes show in solution the typical absorption and emission features of the perylene diimide fragment, with a quantum efficiency close to unity. Moreover, in the solid state (both as spin-coated films and powders) the electronic absorption spectra indicate a reduced fluorophore aggregation and significant quantum yield efficiencies induced by the positive effect of the polyhedral oligomeric silsesquioxane cage.

DNA Triplex‐Mediated Assembly of Polyaromatic Chromophores

The synthesis and characterization of intramolecular triple-helical DNA structures containing polyaromatic pyrene and perylene (perylenetetracarboxylic acid diimide, PDI) building blocks are presented. Two 1,8-dialkynylpyrene units are located in the Watson-Crick stem of the construct, while a PDI or a natural thymidine is present in the Hoogsteen strand. The triple helical structures were investigated by UV/VIS absorbance, fluorescence spectroscopy, and circular dichroism (CD) measurements. The folding of the intramolecular triple helix can be monitored by changes in the vibronic transition ratios, as well as by a change in the alkynylpyrene fluorescence (monomer vs. excimer). It is shown that thymine in the third strand has a pronounced influence on the interaction and, thus, on the fluorescence properties of two pyrene building blocks.

Synthesis and Aggregation Properties of Polycationic Perylenetetracarboxylic Acid Diimides

AbstractThe synthesis and structural characterization of a first family of dendronized polycationic perylenetetracarboxylic acid diimides (PDIs) 7, 8, and 10 is reported. They were obtained by amide coupling reactions of pyridinium salt head groups with terminal carboxylic groups of Newkome‐dendron‐type functionalized PDIs. Resulting pyridinium‐terminated PDIs 7, 8, and 10 are highly water‐soluble, independent of the pH value. This is due to 6, 18, and 9 permanent positive charges, respectively. PDIs 7 containing the smaller first‐generation dendrons exhibit a pronounced aggregation behavior in water. This was studied by absorption and fluorescence spectroscopy, by pulsed‐gradient spin‐echo (PGSE, DOSY) NMR measurements, and by cryo‐transmission electron microscopy (cryo‐TEM). The counterparts containing the bulkier second‐generation dendrons hamper aggregation, and as a consequence intermolecular π–π stacking interactions between the perylene cores is suppressed.

In Situ Monitoring Alzheimer's Disease β‐Amyloid Aggregation and Screening of Aβ Inhibitors Using a Perylene Probe

A cationic perylene tetracarboxylic acid diimide derivative (1) is employed as a probe for in situ monitoring of Aβ aggregation and screening Aβ inhibitors. The assay is based on the fluorescence change through the aggregation of compound 1 following Aβ assembly. Importantly, this probe, compared with the well known amyloid-staining compound thioflavin T (ThT), is more sensitive to Aβ oligomer, which is highly toxic and plays a crucial role in the early stages of Alzheimer's disease.

Fabrication of aligned microwire arrays of perylene bisimide by micromolding in capillary

In this work, we synthesized a novel perylene tetracarboxylic acid diimides derivative (APBI-G) which shows a strong self-assembling tendency to the semiconducting nano/microwires based on the augmented intermolecular hydrogen bonding interaction. We demonstrate the spinning of continuous thread of APBI-G from the liquid–liquid interface and also the fabrication of patterned nano/microwire arrays using MIMIC (micromolding in capillaries) method. MIMIC-fabricated APBI-G nano/microwires showed the excellent uniaxial orientation, large birefringence, and reproducible electrical conductivity (1.93 ± 0.47 × 10 −6 S cm −1).

Organic Thin-Film Solar Cells Using Electron-Donating Perylene Tetracarboxylic Acid Derivatives

Various electron-donating amino groups were introduced into the perylene core of perylene tetracarboxylic acid derivatives (PTCs) to address the potential use in organic solar cells. Broad absorptions of the PTC solutions in the visible to near-infrared (NIR) region suggest that PTCs are promising light-harvesting molecules for solar cells. Electrochemical measurements reveal that the introduction of the electron-donating amino groups makes the energy level of the highest occupied molecular orbital (HOMO) shallow, imparting electron-rich characteristics to the PTCs. The electronic properties of the PTCs are studied on the basis of quantum chemical calculations. The results show that the variation of the amino groups has a significant influence on the HOMO level, while the lowest unoccupied molecular orbital (LUMO) level is relatively sensitive to the electronegativity of the PTC terminal atoms. The PTC thin films exhibit broad absorption bands in the visible to NIR region, as for the PTC solutions, and possess relatively shallow HOMO and LUMO energies that are higher or comparable to those of fullerene C60. These excellent properties encouraged us to employ amine-substituted PTCs as electron donors in a thin film solar cell with C60 as an n-type semiconductor. Photovoltaic devices with a structure of indium tin oxide (ITO)/PTCs/C60/bathocuproine (BCP)/Al were fabricated by spin-coating PTCs on an ITO electrode. The devices with perylene tetracarboxylic acid diimides (PTCDIs), bearing highly basic amino groups (Py-PTCDI, Me2N-PTCDI, and Ph2N-PTCDI), exhibit the higher power conversion efficiencies than those with carbazoyl PTCDI (Cz-PTCDI) and perylene tetracarboxylic acid dianhydrides (PTCDAs). The higher device performance originates from the efficient electron transfer from the PTCs to C60 as the results of the relatively shallow HOMO and LUMO levels of the PTCs bearing the highly basic amino groups. The dependence of the device performance on the PTC film thickness indicates that the introduction of diphenylamino groups on the perylene core suppresses the nonradiative decay of the exciton without decreasing the hole mobility. These results will provide important information for the molecular design of post PTC derivatives.

P-n Type Heterostructures Based on N,N′-Dimethyl Perylene-Tetracarboxylic Acid Diimide

Photovoltaic properties of new photosensitive p-n type heterostructures based on N,N′-dimethyl perylene-tetracarboxylic acid diimide and organic [pentacene, hexathiopentacene, lead phthalocyanine] and inorganic [CuI] semiconductors are investigated. The basic attention is focused on the influence of energy diagram parameters and substrate temperatures (T s) during the deposition on the photosensitivity of heterostructures. The maximal photovoltage, minimal surface recombination rate, and structural homogeneity of layers for the heterostructures were obtained at T s = 370 K. The comparison of the obtained results with energy diagram parameters according to the Anderson model (without taking surface states into account) shows a qualitative agreement for two-layered organic p-n heterojunctions.

Palladium Complexes of Perylene Diimides: Strong Fluorescence Despite Direct Attachment of Late Transition Metals to Organic Dyes

We prepared the first sigma-bonded metal complexes of widely utilized organic dyes, perylene tetracarboxylic acid diimides (PDIs). These 1,7-dipalladium PDI complexes were synthesized by C-Br oxidative addition of 1,7-dibromo-N,N'-dicyclohexyl PDI (Br2PDI) to Pd(0) phosphine complexes bearing triphenylphosphine and bischelating 1,2-bis(diphenylphosphino)ethane (dppe). The structures of Pd-PDI complexes were elucidated by single-crystal X-ray analysis. Surprisingly, despite direct attachement of two late transition metal centers, Pd-PDI systems are highly fluorescent (Phi=0.65 and 0.22 for triphenylphosphine and dppe systems, respectively). This is rationalized in terms of weak electronic interactions between the metal centers and PDI pi-system, as revealed by TD-DFT calculations.