Perylene Diimide Research Articles

Heptannulated Perylene Diimides: Formation and Reactivity of Electron‐Deficient Tropylium Cations and Heptafulvenes

The development of new π‐conjugated motifs opens pathways to previously unexplored classes of organic semiconductors and functional dyes. In this study, five‐ and seven‐membered carbocycles were fused at the ortho and bay regions of electron‐deficient perylenes, starting from a common dialdehyde precursor. Structural analysis of the resulting perylene tetraesters, dianhydrides, and diimides (PDIs) revealed three distinct ring‐fusion patterns and defined stereochemistry. The fused PDI cycloheptatrienes demonstrated susceptibility to acid‐catalyzed transarylation, involving tropylium cation intermediates, which can be used preparatively. Under superacidic conditions, the PDI tropylium cations were directly observed and shown to undergo hydride‐transfer reductions. Additionally, a fused PDI bis(heptafulvene) was synthesized by dehydrogenating a suitably substituted PDI cycloheptatriene. The final system contains two quinomethane units, which can be protonated to yield a stable tropylium‐like dication.

Heptannulated Perylene Diimides: Formation and Reactivity of Electron-Deficient Tropylium Cations and Heptafulvenes.

The development of new π-conjugated motifs opens pathways to previously unexplored classes of organic semiconductors and functional dyes. In this study, five- and seven-membered carbocycles were fused at the ortho and bay regions of electron-deficient perylenes, starting from a common dialdehyde precursor. Structural analysis of the resulting perylene tetraesters, dianhydrides, and diimides (PDIs) revealed three distinct ring-fusion patterns and defined stereochemistry. The fused PDI cycloheptatrienes demonstrated susceptibility to acid-catalyzed transarylation, involving tropylium cation intermediates, which can be used preparatively. Under superacidic conditions, the PDI tropylium cations were directly observed and shown to undergo hydride-transfer reductions. Additionally, a fused PDI bis(heptafulvene) was synthesized by dehydrogenating a suitably substituted PDI cycloheptatriene. The final system contains two quinomethane units, which can be protonated to yield a stable tropylium-like dication.

5-Hydroxymethyl Furfural Oxidation by Perylene Diimide-Sensitized Electrodes Boosted by Photoinduced Doping.

We explored the electrochemical behavior of antimony-doped tin oxide (ATO) and perylene diimide (PDI)-sensitized ATO (ATO-PDI) for the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) mediated conversion of 5-hydroxymethyl furfural (HMF) to 2,5-furandicarboxylic acid (FDCA), a value-added substrate for alternative polymer synthesis. We first showed that ATO displayed good electrocatalytic properties towards TEMPO, affording a quasi-reversible response with a heterogeneous rate constant on the order of 2×10-4 cm s-1. We then evaluated the performance of ATO under exhaustive electrolysis of HMF in basic aqueous electrolyte, reaching 80 % Faradaic Efficiency (FE) for FDCA production. Interestingly, a significantly enhanced current (up to 2.5 mA cm-2) was recorded over time when ATO-PDI was exposed to prolonged visible illumination in a Dye-Sensitized Photoelectrochemical Cell (DSPEC) configuration, which we ascribed to the photoinduced doping of ATO resulting from the oxidative quenching of PDI excited states. The proposed system enabled the production of FDCA with ca. 75 % FE in <2 h reaction time, and an almost quantitative HMF conversion when both the mono- and di-acid products were considered. To the best of our knowledge, this is the first example of a molecular dye-sensitized interface used for the TEMPO-mediated oxidation of HMF.

Spontaneous Formation of Polymeric Nanoribbons in Water Driven by π–π Interactions

AbstractA simple method was developed to produce polymeric nanoribbons and other nanostructures in water. This approach incorporates a perylene diimide (PDI) functionalized by triethylene glycol (TEG) as a hydrophobic supramolecular structure directing unit (SSDU) into the core of hydrophilic poly(N,N‐dimethylacrylamide) (PDMAc) chains using RAFT polymerization. All PDI‐functional polymers dissolved spontaneously in water, forming different nanostructures depending on the degree of polymerization (DPn): nanoribbons and nanocylinders for DPn=14 and 22, and spheres for DPn&gt;50 as determined by cryo‐TEM and SAXS analyses. UV/Vis absorption spectroscopy was used to monitor the evolution of the PDI absorption signal upon dissolution. In solid form, all polymers show a H‐aggregate absorption signature, but upon dissolution in water, the shortest DPn forming nanoribbons evolved to show HJ‐aggregate absorption signals. Over time, the J‐aggregate band increased in intensity, while cryo‐TEM monitoring evidenced an increase in the nanoribbon's width. Heating the nanoribbons above 60 °C, triggered a morphological transition from nanoribbons to nanocylinders, due to the disappearance of J‐aggregates, while H‐aggregates were maintained. The study shows that the TEG‐PDI is a powerful SSDU to promote 2D or 1D self‐assembly of polymers depending on DPn through simple dissolution in water.

Spontaneous Formation of Polymeric Nanoribbons in Water Driven by π-π Interactions.

A simple method was developed to produce polymeric nanoribbons and other nanostructures in water. This approach incorporates a perylene diimide (PDI) functionalized by triethylene glycol (TEG) as a hydrophobic supramolecular structure directing unit (SSDU) into the core of hydrophilic poly(N,N-dimethylacrylamide) (PDMAc) chains using RAFT polymerization. All PDI-functional polymers dissolved spontaneously in water, forming different nanostructures depending on the degree of polymerization (DPn): nanoribbons and nanocylinders for DPn=14 and 22, and spheres for DPn>50 as determined by cryo-TEM and SAXS analyses. UV/Vis absorption spectroscopy was used to monitor the evolution of the PDI absorption signal upon dissolution. In solid form, all polymers show a H-aggregate absorption signature, but upon dissolution in water, the shortest DPn forming nanoribbons evolved to show HJ-aggregate absorption signals. Over time, the J-aggregate band increased in intensity, while cryo-TEM monitoring evidenced an increase in the nanoribbon's width. Heating the nanoribbons above 60 °C, triggered a morphological transition from nanoribbons to nanocylinders, due to the disappearance of J-aggregates, while H-aggregates were maintained. The study shows that the TEG-PDI is a powerful SSDU to promote 2D or 1D self-assembly of polymers depending on DPn through simple dissolution in water.

Polyimide-based triazine-cored covalent organic frameworks supported metal (Fe, Ni, Ru and Rh) nanoparticles for high-efficiency electrocatalytic hydrogen evolution

Covalent organic frameworks (COFs) have great potential in electrocatalytic hydrogen evolution reaction (HER). Nevertheless, it is a challenging task to fabricate COF-based electrocatalysts with low overpotential and high stability for HER in acidic media. Herein, a series of polyimide-based triazine-cored COFs (PIT-COFs) with different aromatic diimides are designed to support metal (Fe, Ni, Ru and Rh) nanoparticles for electrocatalytic HER. PIT-COFs are obtained by the reaction between melamine and aromatic (benzene, biphenyl, naphthalene and perylene) diimides. PIT-COFs based on perylenediimide show the optimal electrocatalytic HER activity in acidic media due to its large π-conjugated structure. Rh@COFMA-PT has a low overpotential value of 70 mV at 10 mA cm−2 and a small Tafel slope of 56.58 mV dec−1, which surpasses numerous previously published HER electrocatalysts. Furthermore, Rh@COFMA-PT exhibits good electrocatalytic stability and still keeps high activity after 3000 cycles. The conjugated nitrogen-rich structures of PIT-COFs and their ability to effectively anchor metal nanoparticles as active sites significantly promote the electron and proton transport during the electrocatalytic HER process. This work offers a guideline for developing effective and stable COF-based HER electrocatalysts with abundant active sites.

Perylene- and Perylene Diimide-based Framework Materials Constructed through Metal Coordination.

Metal-organic frameworks (MOFs) are a class of materials composed by coordinative interactions between metal ions and organic linkers, encompassing two-dimensional (2D), and three-dimensional (3D) architectures. Metal-organic cages (MOCs), a special case of these species, are discrete molecular "capsules" with zero-dimensional (0D) structures. Over the last two decades, MOFs and MOCs composed of organic perylene (P) and perylene diimide (PDI) linkers have gained much attention due to their versatile properties, which can be further enhanced after incorporation into the frameworks. This minireview highlights recent progress in the construction and application of P/PDI-based coordination framework materials. The text offers an overview of the synthesis of P/PDI organic linkers, proceeds to their integration into coordination frameworks of different dimensionalities - 2D and 3D MOFs, and 0D MOCs, and then explores potential applications. These include sensing, photocatalysis, electrochemical devices as well as photothermal conversion and focus on the apparent structure-property relationships. Finally, the challenges and future prospects of P/PDI-derived coordination frameworks will be addressed.

Planar Chiral Charge-Transfer Cyclophanes: Convenient Synthesis, Circularly Polarized Light-Responsive Photothermal Conversion and Supramolecular Chiral Assembly.

We report herein a series of macrocycles in which the densely π-stacked charge-transfer (CT) donor/acceptor with naphthalenediimides (NDIs) or perylene diimide (PDI) as acceptor moiety pairing various donor moieties are locked by covalent bond. The X-ray crystallography of C8BDT-NDI reveals a short intramolecular π-stacking distance around 3.4 Å and the existence of intermolecular donor/acceptor π-stacking (3.7 Å). The intramolecular CT is highly dependent on the electron-donating ability of donor moiety and replacing carbazole (C8KZ) with benzo[1,2-b:4,5-b']dithiophene (C8BDT) or dihydroindolo[3,2-b]indole (C8DN) redshift CT absorption into NIR region. Notably, both C8BDT-NDI and C8DN-NDI demonstrate excellent photothermal performance, which is a result of the active non-radiative pathways. Interestingly, the different molecular symmetry between donor and acceptor moiety in cyclophanes endow C8BDT-NDI and C8DN-NDI with intrinsic planar chirality. The enantiomeric C8BDT-NDI shows chiral selectivity for incident light, i.e., when irradiated by left-circularly polarized light, (R)-C8BDT-NDI is more sensitive and a higher maximum stable temperature is achieved. While, enantiomeric C8DN-NDI pack with different orientations forming M- and P-handedness helix, respectively, demonstrating molecular planar chirality being transferred and amplified through molecular assembly. These results provide insight into the intramolecular charge transfer in enforced D/A π-stacks in which CT interactions and planar chirality would be engineered through structural control.

Planar Chiral Charge‐Transfer Cyclophanes: Convenient Synthesis, Circularly Polarized Light‐Responsive Photothermal Conversion and Supramolecular Chiral Assembly

AbstractWe report herein a series of macrocycles in which the densely π‐stacked charge‐transfer (CT) donor/acceptor with naphthalenediimides (NDIs) or perylene diimide (PDI) as acceptor moiety pairing various donor moieties are locked by covalent bond. The X‐ray crystallography of C8BDT‐NDI reveals a short intramolecular π‐stacking distance around 3.4 Å and the existence of intermolecular donor/acceptor π‐stacking (3.7 Å). The intramolecular CT is highly dependent on the electron‐donating ability of donor moiety and replacing carbazole (C8KZ) with benzo[1,2‐b:4,5‐b′]dithiophene (C8BDT) or dihydroindolo[3,2‐b]indole (C8DN) redshift CT absorption into NIR region. Notably, both C8BDT‐NDI and C8DN‐NDI demonstrate excellent photothermal performance, which is a result of the active non‐radiative pathways. Interestingly, the different molecular symmetry between donor and acceptor moiety in cyclophanes endow C8BDT‐NDI and C8DN‐NDI with intrinsic planar chirality. The enantiomeric C8BDT‐NDI shows chiral selectivity for incident light, i.e., when irradiated by left‐circularly polarized light, (R)‐C8BDT‐NDI is more sensitive and a higher maximum stable temperature is achieved. While, enantiomeric C8DN‐NDI pack with different orientations forming M‐ and P‐handedness helix, respectively, demonstrating molecular planar chirality being transferred and amplified through molecular assembly. These results provide insight into the intramolecular charge transfer in enforced D/A π‐stacks in which CT interactions and planar chirality would be engineered through structural control.

Redox‐Neutral Cascade Trifluoromethylation of Dienes and Enynes using a Perylene Diimide (PDI) Organophotocatalyst

The Perylene diimide (PDI) is an underexplored synthetic organic dye with significant potential in photoredox catalysis. We have developed a good chemo‐ and regioselective, atom‐economical methodology for synthesizing trifluoroethylated saturated heterocyclic derivatives and trifluoroethyl‐containing cyclobutane derivatives. This process involves the generation of trifluoromethyl radical from the Langlois (CF&lt;sub&gt;3&lt;/sub&gt;SO&lt;sub&gt;2&lt;/sub&gt;Na) reagent under photoredox conditions, which selectively reacts with the electron‐rich terminal double/triple bonds in the diene/enyne framework. The resulting intermediate undergoes a cascade cyclization, yielding the desired compounds in a redox‐neutral manner. Our methodology operates under very mild conditions, eliminating the need for transition metals and external oxidizing agents. It is broadly applicable across various substrates and is supported by comprehensive mechanistic insights from regular photophysical experiments.

Acceptor-acceptor′-acceptor type N-annulated perylenediimide dimeric acceptors at the outside-bay position: Synthesis and role of asymmetric 4,7-di(thien-2-yl)-5-fluorobenzothiadiazole linker

Acceptor-acceptor′-acceptor (A-A′-A) type N-annulation perylene diimide (PDI) dimeric acceptors possessed the fascinating merits but were ignored. Herein, two A-A′-A type N-annulated PDI dimers, termed as, DTBT-(PPDI-B)2 and DTFBT-(PPDI-B)2, in which the electron-deficient moieties 4,7-di(thien-2-yl)benzothiadiazole (DTBT) and monofluorinated 4,7-di(thien-2-yl)-5-fluorobenzothiadiazole (DTFBT) were selected as the central linkers and two N-annulation N-butyl-[1,12-b,c,d]pyrrole-N,Nʹ-bis(2-hexyldecyl)perylenediimide (PPDI-B) aromatic rings as the dual wings were explored. The annulation-free DTBT-(PDI-HD)2 was chosen as reference material. Owing to electron-donating of the newly formed pyrrolic aromatic ring, these studied N-annulated acceptors possessed the improved absorption and up-shifted ELUMO than those of the counterpart DTBT-(PDI-HD)2. Both of them exhibited the wide absorption spectra spanning from 300 nm to 700 nm, the similar aggregation and good photostability in solution. Monofluorinating the central benzothiadiazole linker gave the enhanced absorption, the down-shifted EHOMO and ELUMO, the reduced the dihedral angle from 9.09° to 3.64° between two N-annulated PPDI sub-planes and the enhanced solid stacking and aggregation. As a result, the N-annulation modification achieved the 0.16 V increased VOC, decreased JSC and FF, and thus the reduced PCE of 0.90 %. Moreover, the 21.33 % increased JSC of 3.64 mA cm−2 and the 35.58 % raised FF up to 42.68 % were observed in the monofluorinated PTB7-Th:DTFBT-(PPDI-B)2-based device, synergistically contributing to an 62.22 % elevated PCE of 1.46 % in spite of a 0.01 V dropped VOC. This upgradation was predominantly profited from the increased absorption, the improved exciton dissociation, elevated electron mobility and improved microstructural morphology benefiting from introducing the asymmetric 4,7-dithienyl-5-fluorobenzothiadiazole. This work demonstrates that outside bay N-annulation strategy could tune the molecular structure, energy level and thus improve the voltage, and monofluorinating the central linker is an effective tactic for regulating the molecular configuration, aggregation, morphology and thus elevating the photovoltaic performance in the A-A′-A type N-annulated PDI dimeric acceptors.

Stable radicals in bacteria composites hybridized by a doubly-strapped perylene diimide for near-infrared photothermal conversion

Stable radicals in bacteria composites hybridized by a doubly-strapped perylene diimide for near-infrared photothermal conversion

A-A′-A structured methoxy-modified perylenediimide dimeric acceptors at the outside-bay position: Synthesis, spectroscopic property and photovoltaic application

Acceptor-acceptor′-acceptor (A-A′-A) structured methoxy-modified perylene diimide (PDI-OMe) electron acceptors weren′t fully investigated so far. Herein, two A-A′-A type dimeric acceptors, denoted as DTBT-(PDI-OMe)2 and difluorinated DTFFBT-(PDI-OMe)2, where two methoxy-modified PDI-OMe subunits as biswings and electron-deficient units 4,7-di(thien-2- yl)benzothiadiazole (DTBT) and difluorinated 4,7-di(thien-2-yl)-5,6-difluorobenzothiadiazole (DTFFBT) as central linkers, were developed. And the methoxy-free DTBT-(PDI-HD)2 was utilized as reference material. Owing to the electron-donating characteristic of incorporating methoxy group at the outside bay position of PDI, DTBT-(PDI-OMe)2 possessed an enlarged optical bandgap but improved light-capturing ability, weakened aggregation and up-shifted ELUMO. Moreover, the decreased the thermal- and photo-stability, slightly red-shifted maximum absorption, the reduced the bandgap, weakened aggregation and the deepened ELUMO were seen after further difluorinating the central benzothiadiazole linker. Thereupon, compared with DTBT-(PDI-HD)2, PTB7-Th:DTBT-(PDI-OMe)2-based device achieved a 0.07V increased VOC of 0.86V, an 5.91% enhanced JSC of 3.94mAcm2 and a 20.69% elevated FF of 42.23% and thus a 38.83% raised PCE of 1.43%. Moreover, the further difluorinating the central benzothiadiazole linker led to a 20.98% decreased PCE of 1.13%, which was mainly limited by the 0.07V decreased VOC and 15.65% dropped FF regardless of slightly increased JSC in the DTFFBT-(PDI-OMe)2-based device. The dropped PCE was mainly due to the enlarged charge recombination, reduced electron mobility resulted from the weakened aggregation and insufficient microstructural phase separation. The work suggested that introducing the methoxy substituent at the outside bay position was an effective strategy for enhancing the voltage and efficiency, but it should be cautious to further incorporate fluorine atoms into the central electron-deficient linking cores during the A-A′-A structured methoxy-modified PDI dimers for high performance photovoltaic device.

Perylene diimide configuration to construct g-C3N4 and iron phthalocyanine composite catalyst as PMS activator for contaminant degradation

The photocatalysis-assisted peroxymonosulfate (PMS) activation process has shown great potential for organic wastewater treatment. Herein, the composite photocatalyst (FeTAPc/PDI/CN) was obtained by grafting graphitic carbon nitride (CN) and amino iron phthalocyanine (FeTAPc) onto both ends of perylene tetracarboxylic anhydride (PTCDA) through an imidization process. Under simulated solar irradiation, the catalyst exhibited a remarkable degradation performance toward the target pollutant by activated PMS over a wide pH range from 3 to 11. The degradation efficiency of SMX reached 100 % in 7 min with the reaction kinetic constant of 0.845 min−1, which was 13 times higher than that of pure CN. In addition, the removal rate of FeTAPc/PDI/CN-4 for SMX was more than 80 % after 9 cycles. The introduction of phthalocyanine and PDI improved the separation efficiency of photogenerated electron-hole pairs. Furthermore, the active species involved in the SMX degradation were identified as •OH, SO4•-, •O2– and 1O2. The possible degradation pathways were proposed based on the identified intermediates, in which the oxidation of the amino group on the benzene ring was the main degradation pathway. This study is anticipated to result in a favorable method for designing CN-based photocatalysts with high stability and excellent catalytic activity for environmental remediation.

Fluence-Dependent Photoinduced Charge Transfer Dynamics in Polymer-Wrapped Semiconducting Single-Walled Carbon Nanotubes.

Because an individual single-walled carbon nanotube (SWNT) can absorb multiple photons, the exciton density within a single tube depends upon excitation conditions. In SWNT-based energy conversion systems, interactions between excitons and charges make it possible for multiple types of charge transfer reactions. We exploit a SWNT-molecular donor-acceptor hybrid system (R-PBN(b)-Ph6-PDI-[(6,5) SWNT]) that fixes spatial organization and stoichiometry of perylene diimide (PDI) electron acceptors on the nanotube surface, to elucidate how excitation fluence affects ultrafast charge separation (CS) and the nature of charge recombination (CR) dynamics triggered upon SWNT near-infrared excitation. Pump-probe data characterizing these photoinduced CS and thermal CR reactions were acquired over excitation fluences that produce ∼5-125 excitons per 700 nm long nanotube. These experiments show that optical excitation gives rise to CS states in which PDI radical anions (PDI-•) and SWNT hole polarons (SWNT•+) have geminate and nongeminate spatial relationships. Under low excitation fluences, the observed dynamics reflect CR reactions of these geminate and nongeminate CS states. As excitation fluence increases, persistent excitons, which have not undergone CS, undergo reaction with ([SWNT(•+)n]-(PDI-•)n) CS states to produce lower-energy CS states that are characterized by hole (SWNT•+) and electron (SWNT•-) polarons. When nongeminate SWNT•+ and SWNT•- charge carriers are generated, CR dynamics depend on the time scale required for these oppositely charged solvated SWNT polarons to encounter each other. Because SWNT excitons have substantial excited-state reduction (1E-/*) and excited-state oxidation (1E*/+) potentials, they can drive additional charge transfer reactions involving initially prepared CS states under experimental conditions where excess excitons are present.

Solution-processing induced H-aggregate of Perylene-Diimide Zwitterion Exhibiting Compact Molecular Stacking toward Efficient Cathode Modification in Organic Solar Cells.

High-performance organic cathode interlayers (CILs) play a crucial role in the advance of organic solar cells (OSCs). However, organic CILs have exhibited inferior performances to their inorganic counterparts over a long time, due to the inherent shortcoming of poor charge transporting capability. Here, we designed and synthesized a perylene-diimide (PDI) zwitterion PDI-B as high-performance organic CIL for OSCs. We revealed that an obvious H-aggregate of PDI-B was formed during the solution processing, thereby significantly enhancing the charge transporting capability of the CIL. Compared to the classic PDINN, the π-π stacking distance of PDI-B was reduced from 4.2 Å to 3.9 Å, which further facilitated the charge transport. Consequently, PDI-B showed a high conductivity of 1.81×10-3S/m; this is comparable to that of inorganic CILs. The binary OSC showed an elevated PCE of 19.23 %, which is among the highest PCE values for binary OSCs. Benefitting from improved solvent resistance and good compatibility with large-area processing method of PDI-B, the photovoltaic performances of inverted and 1-cm2 OSC were significantly improved. The results from this work provide a new approach of optimizing the condensed structure of PDI film to boost the charge conductivity, opening an avenue to develop high-performance PDI-based CILs.

Dual-mode electrochemical and electrochemiluminescence detection of dopamine based on perylene diimide self-assembly material.

The self-assembly materialN,N-bis-(3-dimethyl aminopropyl)-3,4,9,10-perylene tetracarboxylic acid diimide (PDI) isreported to show electrochemical (EC)/electrochemiluminescence (ECL) property for designing new dual-mode dopamine (DA) sensors. K2S2O8 significantly improved the EC reduction current at -0.346V and ECL intensity at -0.25V of thePDI self-assembly material. DA largely decreased the EC reduction current and ECL intensity of this homogeneous EC/ECL material due to the competitive consumption of K2S2O8 in theoxidization process of DA and the low electron conductivity of polyDA formed through the oxidization of DA by K2S2O8. In addition, the ECL quenching mechanism involved an energy-transfer process resulting from the collision between the produced o-benzoquinone species (oxidization of DA) and the excited state of PDI, which decreased the ECL intensity. This homogeneous EC/ECL material showed linear EC current response for DA from 5.0 nM to 50.0 µM with a detection of limit of 2.7 nM and linear ECL response for DA from 1.0 nM to 100.0 µM with a detection of limit of 0.41 nM. Theproposed dual-mode EC/ECL sensors also showed good feasibility in urine sample analysis.

Investigations of Crucial Factors for the Non-Covalent Functionalization of Black Phosphorus (BP) using Perylene Diimide Derivatives for the Passivation of BP Nanosheets.

The non-covalent functionalization of black phosphorus (BP) was studied with a scope of ten tailor-made perylene diimides (PDIs). A combination of UV/Vis-, fluorescence-, as well as Raman spectroscopy and atomic force microscopy was used to investigate the structural factors, which contribute to a pronounced PDI-BP interaction and thus support the protection of BP nanosheets against oxidative degradation. We were able to show, that water-soluble, amphiphilic PDIs with highly charged head groups can be used for the non-covalent functionalization of BP in aqueous media. Here, based on the hydrophobic effect, an efficient adsorption of the respective PDI molecules takes place and leads to the formation of a passivating film, yielding a considerable stabilization of the BP flakes under ambient conditions exceeding 30 days.

MAPLE-Deposited Perylene Diimide Derivative Based Layers for Optoelectronic Applications.

Nowadays, the development of devices based on organic materials is an interesting research challenge. The performance of such devices is strongly influenced by material selection, material properties, design, and the manufacturing process. Usually, buckminsterfullerene (C60) is employed as electron transport material in organic photovoltaic (OPV) devices due to its high mobility. However, considering its low solubility, there have been many attempts to replace it with more soluble non-fullerene compounds. In this study, bulk heterojunction thin films with various compositions of zinc phthalocyanine (ZnPc), a perylene diimide derivative, or C60 were prepared by matrix-assisted pulsed laser evaporation (MAPLE) technique to assess the influence of C60 replacement on fabricated heterostructure properties. The investigations revealed that the optical features and the electrical parameters of the organic heterostructures based on this perylene diimide derivative used as an organic acceptor were improved. An increase in the JSC value (4.3 × 10-4 A/cm2) was obtained for the structures where the perylene diimide derivative acceptor entirely replaced C60 compared to the JSC value (7.5 × 10-8 A/cm2) for the heterostructure fabricated only with fullerene. These results are encouraging, demonstrating the potential of non-fullerene compounds as electron transport material in OPV devices.

Modified perylene diimide for femto molar level detection of glucose: smartphone-assisted colorimetric glucose detection kits.

In this report, a functionalized hydroxyphenyl benzothiazole (HBT) derivative has been synthesized and anchored onto the perylene diimide (PDI) core at the -bay position (PHI). PHI has been explored for the generation of radical anions (PH1˙-) and dianions (PH12-) in 20% HEPES buffer-DMSO solution using H2S as a sacrificial electron donor. The PH1˙- has a half-life (t1/2) of 1.5 h and 3 h in oxygenated and hypoxic conditions, respectively. The formation of radical anions has been confirmed by optical (absorbance and fluorescence) methods, cyclic voltammetry (CV), differential pulse voltammetry (DPV), and femtosecond transient absorbance spectroscopy along with current-voltage (I-V) and NOBF4 studies. The PH1˙- showed peroxidase-like activity for the reduction of H2O2 as low as 170 fmol L-1 (fM) giving a colour change from sea green to pink. The biochemical assay which consists of PH1˙-+ GOx has been further utilized as a glucose sensor. Upon addition of glucose (0-8 nM) in the biochemical assay, the in-situ produced H2O2 (after oxidation of glucose with GOx) oxidized PH1˙- to PH1 giving a sea green to pink colorimetric read out along with a decrease in the absorption intensities at 720, 815, 880 and 950 nm and the emergence of absorption intensity at 541 nm. The lowest limit of detection is 85 fM. We also explored this biochemical assay for the detection of 860 fM of glucose in a 10% blood serum. Similarly, fluorometric, CV and DPV studies were carried out for the detection of glucose using this biochemical assay. The smartphone-assisted RGB colour analyser showed large variations in the red colour and this RGB based colour differentiation can be used for the detection of 1 nM of glucose.