Pyrene Derivatives Research Articles

Synthesis and Luminescence Property of Pyrene Derivatives Including Diphenyl-Imidazole Moiety

We have designed and synthesized blue emitting compounds, DBF-PI and DBT-PI, by incorporating pyrene and imidazole groups as main chromophore and introducing dibenzofuran and dibenzothiophene groups. Pyrene and diphenyl-imidazole were used to synthesize blue emitters of 1-(4-Dibenzofuran-4-yl-phenyl)-4,5-diphenyl-2-pyren-1-yl-1H-imidazole (DBF-PI) and 1-(4-Dibenzothiophen-4-yl-phenyl)-4,5-diphenyl-2-pyren-1-yl-1H-imidazole (DBT-PI). The optical and electroluminescence properties of newly synthesized materials were measured. Both materials emit blue photoluminescence in the film state and DBF-PI have a high PLQY value of about 80% in solution state. The synthesized materials were applied as EML in non-doped devices, and high efficiency of 2.92 cd/A and EQE of 2.07% in DBF-PI device were achieved.

Modification of electron structure on the semiconducting single-walled carbon nanotubes for effectively electrosensing guanine and adenine

The as-prepared SWNTs are always a mixture of metallic (m-) and semiconducting (s-) tubes with quite different electrochemical properties which is a major barrier for their application in many fields. Based on the noncovalent interactions between planar aromatic molecules and SWNTs, the pyrene derivatives 1-docosyloxylmethylpyrene (DomP) was synthesized to separate the m-SWNTs and s-SWNTs via its significant selectivity toward s-SWNTs, i.e. electronic modulation. Before and after doping with electron, the electrochemical properties of s-SWNTs were studied and compared with that of m-SWNTs by electronic absorption spectroscopy, electrochemical impedance spectroscopy and cyclic voltammogram. As demonstrated, the electrocatalytic activity of electron modulated s-SWNTs was significantly improved and even better than m-SWNTs. Thus a novel sensor was constructed with the electron modulated s-SWNTs modified electrode and successfully applied for simultaneous determination of guanine and adenine.

Highly-twisted pyrene derivative for pure-blue organic light emitting diodes

The new fluorescent blue host material, 1,3,6,8-tetrakis(2,5-dimethylbiphenyl-4-yl)pyrene (BD4PP), was synthesized for pure-blue organic light-emitting diodes (OLEDs). BD4PP has highly twisted and steric structure for efficient fluorescence, and has high thermal stability of 492°C. BD4PP host doped with 5wt.% 4,4′-bis(9-ethyl-3-carbazovinylene)-1,1′-biphenyl (BCzVBi) or 5wt. % 1,4-bis[2-(3-N-ethylcarbazoryl)-vinyl]benzene (BCzVB) showed high device efficiencies due to wide bandgap (˜ 3.1eV) and electron-rich host. An OLED with the BD4PP:BCzVB emitter showed higher current and external quantum efficiencies of 4.41cd/A and 3.80% with color coordinates (0.16, 0.13) compared to those of the BD4PP:BCzVBi (3.63cd/A and 3.62%) with color coordinates (0.16, 0.11) and non-doped BD4PP (2.01cd/A and 1.61%) with color coordinates (0.18, 0.13).

Development of Biofuel Cell Using a Complex of Highly Oriented Immobilized His-Tagged Enzyme and Carbon Nanotube Surface Through a Pyrene Derivative.

For increasing the output of biofuel cells, increasing the cooperation between enzyme reaction and electron transfer on the electrode surface is essential. Highly oriented immobilization of enzymes onto a carbon nanotube (CNT) with a large specific surface area and excellent conductivity would increase the potential for their application as biosensors and biofuel cells, by utilizing the electron transfer between the electrode-molecular layer. In this study, we prepared a CNT-enzyme complex with highly oriented immobilization of enzyme onto the CNT surface. The complex showed excellent electrical characteristics, and could be used to develop biodevices that enable efficient electron transfer. Multi-walled carbon nanotubes (MWCNT) were dispersed by pyrene butyric acid N-hydroxysuccinimide ester, and then N-(5-amino-1-carboxypentyl) iminodiacetic acid (AB-NTA) and NiCl₂ were added to modify the NTA-Ni2+ complex on the CNT surface. Pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase (GDH) was immobilized on the CNT surface through a genetically introduced His-tag. Formation of the MWCNT-enzyme complex was confirmed by monitoring the catalytic current electrochemically to indicate the enzymatic activity. PQQ-GDH was also immobilized onto a highly ordered pyrolytic graphite surface using a similar process, and the enzyme monolayer was visualized by atomic force microscopy to confirm its structural properties. A biofuel cell was constructed using the prepared CNT-enzyme complex and output evaluation was carried out. As a result, an output of 32 μW/cm² could be obtained without mediators.

All-Armchair Graphene Nanoribbon Field-Effect Uridine Diphosphate Glucose Sensor: First-Principles In-Silico Design and Characterization

Label-free sensors capable of detecting low concentrations of significant biomolecular substances without inducing immune response would simplify experiments, minimize errors, improve real-time observations, and reduce costs in probing living organisms. This paper presents a first-principles, in-silico derived, all-armchair graphene nanoribbon field-effect transistor (g-FET) device for the detection and measurement of low-concentration (pM-nM) uridine diphosphate glucose, UDP-glucose. UDP-glucose is an intermediate reactant in the synthesis of sucrose in a plant cell’s cytoplasm and an extracellular signaling molecule capable of activating downstream defense mechanisms. The unique g-FET configuration for the semiconducting channel and electrodes favors the fabrication of high-density nanoarray sensors. Optimal device electronic transport and switching properties are predicted by screening configurations with different widths, to control bandgap, and lengths, to control thermionic versus tunneling transport across the semiconducting junction. A self-assembled monolayer (SAM) of pyrene derivatives, 1-pyrenebutyric acid, is used to noncovalently functionalize the graphene surface on one end and to covalently ligate the target analyte on the other while providing mechanical, chemical, and electronic signal sensing stability. We find that the device offers a predicted limit of detection (LOD) of 0.997 / $n$ mM/L (where $n$ is the number of sensor units in an array), with high transconductance sensitivity, 0.75– $1.5\mu \text {S}$ for 1–3 UDP-glucose molecules, at low input ( $V_{G}= 0.9$ V) and output voltages $V_{\text {DS}}=0.1$ V. Thus, a $1000\times1000$ nanoarray sensor would yield an LOD = 0.997 nM/L. This low-power, all-armchair g-FET sensor with SAM ligands that may be chosen to bind different biomarkers provides a unique opportunity for high throughput, real-time, low-cost, high-mobility, and minimal-calibration sensing applications.

Confining Photoacidity

Confining Photoacidity

Noncovalent Functionalization of 2D Black Phosphorus with Fluorescent Boronic Derivatives of Pyrene for Probing and Modulating the Interaction with Molecular Oxygen.

We studied the chemical–physical nature of interactions involved in the formation of adducts of two-dimensional black phosphorus (2D BP) with organoboron derivatives of a conjugated fluorescent molecule (pyrene). Time-resolved fluorescence spectroscopy showed a stabilization effect of 2D BP on all derivatives, in particular for the adducts endowed with the boronic functionalities. Also, a stronger modulation of the fluorescence decay with oxygen was registered for one of the adducts compared to the corresponding organoboron derivative alone. Nuclear magnetic resonance experiments in suspension and density functional theory simulations confirmed that only noncovalent interactions were involved in the formation of the adducts. The energetic gain in their formation arises from the interaction of P atoms with both C atoms of the pyrene core and the B atom of the boronic functionalities, with a stronger contribution from the ester with respect to the acid one. The interaction results in the lowering of the band gap of 2D BP by around 0.10 eV. Furthermore, we demonstrated through Raman spectroscopy an increased stability toward oxidation in air of 2D BP in the adducts in the solid state (more than 6 months). The modification of the electronic structure at the interface between 2D BP and a conjugated organic molecule through noncovalent stabilizing interactions mediated by the B atom is particularly appealing in view of creating heterojunctions for optoelectronic, photonic, and chemical sensing applications.

Noncovalent Functionalization of Carbon Substrates with Hydrogels Improves Structural Analysis of Vitrified Proteins by Electron Cryo-Microscopy.

In electron cryo-microscopy, structure determination of protein molecules is frequently hampered by adsorption of the particles to the support film material, typically amorphous carbon. Here, we report that pyrene derivatives with one or two polyglycerol (PG) side chains bind to the amorphous carbon films, forming a biorepulsive hydrogel layer so that the number of protein particles in the vitreous ice drastically increases. This approach could be extended by adding a hydrogel-functionalized carbon nanotube network (HyCaNet, the hydrogel again being formed from the PG-pyrene derivatives), which stabilized the protein-containing thin ice films during imaging with the electron beam. The stabilization resulted in reduced particle motion by up to 70%. These substrates were instrumental for determining the structure of a large membrane protein complex.

Structure and piezochromism of pyrene-1-carbaldehyde at high pressure.

The crystal structure of pyrene-1-carbaldehyde (PA), a model polyaromatic hydrocarbon, highly luminescent in the solid state and crystallizing in the triclinic system, has been re-determined at several pressures ranging from atmospheric up to 3 GPa using a diamond anvil cell. A `multi-crystal' approach was used in crystal structure determination, significantly improving completeness of X-ray diffraction data attainable for such a low-symmetry system. The crystal structure consists of infinite π-stacks of PA molecules with discernible dimers, which resemble aggregates formed by pyrene derivatives in solution as well as in the solid state. A series of measurements showed that the average inter-planar distance between individual molecules within π-stacks decreases with pressure in the investigated range. This results in piezochromic properties of PA: a significant sample color change as well as a red-shift of fluorescence with pressure, as studied with UV-vis spectroscopy. Periodic DFT calculations allowed us to relate the variations in the crystal structure with pressure to the changes in the electronic structure of this material.

Is it worthwhile to deal with 1,3-disubstituted pyrene derivatives? – Photophysical, optical and theoretical study of substitution position effect of pyrenes containing tetrazole groups

Among disubstituted at non-K region pyrenes, the most number of molecules contain the substituents at positions 1 and 6, followed by 1 and 8 whereas 1,3-disubstituted pyrenes are definitely unexplored. In this work, we present the theoretical calculations based on DFT and TD-DFT methods of 1,3,6,8-tetrasubstituted and 1,6-, and 1,8-disubstituted pyrenes which were confronted with the experimental data of synthesized, based on 1,3-dipolar cycloaddition, tetra- and disubstituted pyrenes derivatives containing tetrazole motif with n-butyl chain, what allow to find optimal parameters of quantum-chemical calculations which are necessary to obtain the reasonable theoretical results for 1,3-disubstituted by (hetero)aryl groups pyrenes. What will allow to answer if it is worthwhile to deal in arduous and laborious work with 1,3-disubstituted pyrene derivatives. Moreover, the knowledge about the differences and similarities among the group of disubstituted pyrenes at positions 1,3-, 1,6-, and 1,8- is crucial for design and synthesis of the materials with expected properties.

Effect of Organic Modification on Multiwalled Carbon Nanotube Dispersions in Highly Concentrated Emulsions.

Highly concentrated water-in-oil emulsions incorporating multiwalled carbon nanotubes (MWCNTs) are prepared. Homogeneous and selective dispersions of MWCNTs throughout the oil phase of the emulsions are investigated. The practical insolubility of carbon nanotubes (CNTs) in aqueous and organic media necessitates the disentanglement of CNT “agglomerates” through the utilization of functionalized CNTs. The design and synthesis of two tetra-alkylated pyrene derivatives, namely, 1,3,6,8-tetra(oct-1-yn-1-yl)pyrene (TOPy) and 1,3,6,8-tetra(dodec-1-yn-1-yl)pyrene (TDPy), for the noncovalent organic modification of MWCNTs are reported. The modifier molecules are designed in such a manner that they facilitate an improved dispersion of individualized MWCNTs in the continuous-oil phase of the highly concentrated emulsion (HCE). Transmission electron microscopic analyses suggest that the alkylated pyrene molecules are adsorbed on the MWCNT surface, and their adsorption eventually results in the debundling of MWCNT agglomerates. Fourier transform infrared, Raman, and fluorescence spectroscopic analyses confirm the π–π interaction between the alkylated pyrene molecules and MWCNTs. The noncovalent modification significantly improves the effective debundling and selective dispersion of MWCNTs in HCEs.

Synthesis, physical properties and electroluminescence of functionalized pyrene derivative

Developing novel polycyclic aromatic hydrocarbons with high stability is of great importance, as well for opto-electronic applications as to provide novel materials for organic soft matter devices. Here the synthesis of a cyclized arene 13 and the corresponding acene-functionalized pyrene derivative 8 are described. Both molecules have been characterized by FT-IR, NMR spectroscopy, and mass spectroscopy. Their opto-electronic properties were determined from their absorption and emission spectra and electrochemistry and by theoretical calculations. Molecules 13 and 8 exhibit respectively a strong orange and cyan fluorescence in dichloromethane with high fluorescence quantum yields of 0.45 and 0.84 respectively, and present enhanced photo- and thermal stability compared to other large acenes. The organic light-emitting diodes using 13 and 8 as emitters were fabricated by via spin-coating way. After optimization they exhibited a maximum brightness of 2647 cd m−2 at 16.4 V with CIE coordinate of (0.61, 0.39) and 5620 cd m−2 at 7.2 V with CIE coordinate of (0.28, 0.64), respectively.

Composite Films of Waterborne Polyurethane and Few-Layer Graphene—Enhancing Barrier, Mechanical, and Electrical Properties

Graphene has excellent mechanical, thermal, and electrical properties. Graphene can serve as potential reinforcement in polymer-based nanocomposites. In order to achieve this goal, graphene has to be distributed homogeneously and dispersed throughout the polymer matrix, establishing a strong interface with the polymer. Solution mixing is an interesting method for the preparation of homogeneous nanocomposites, in particular when using environmentally friendly solvents such as water. The major difficulty met in the production of graphene/polymer composites concerns the preparation and stabilization of graphene in aqueous suspension. In the present work three different graphite-based materials, with different crystallinity and purity grades, were exfoliated in aqueous solution of an amphiphilic pyrene derivative, forming few-layer graphene (FLG). The FLG prepared was dispersed in waterborne polyurethane (WPU) to produce composite films. The composite films were produced by solvent casting and spray coating, forming free-standing films that were characterized in terms of its distribution of FLG through the composite, its permeability to water vapor, its electrical resistivity, and its mechanical properties. The studies demonstrated the influence of different factors on the composite film properties such as the use of graphite vs. FLG, the FLG lateral dimensions, and the FLG composition and composite preparation method.

Synthesis, Structures and Lewis‐Acid‐Induced Isomerization of 8‐Methoxy[2.2]metaparacyclophanes and a DFT Study

AbstractMethyl substituted 8‐methoxy[2.2]MPCPs 8 a–b were obtained via the corresponding thiacylophanes and its oxidized products. Lewis acid‐catalyzed (AlCl3‐MeNO2) reactions of 5‐tert‐butyl‐8‐methoxy‐12,13,15,16‐tetramethyl[2.2]MPCP 8 b under various conditions led to transannular cyclization and isomerization reactions, affording the considerably less‐strained 5‐tert‐butyl‐8‐methoxy[2.2]MPCP 9, 5‐tert‐butyl‐8‐hydroxy‐14,16,17,18‐tetramethyl[2.2]metacyclophane 10 and pyrene derivatives 11 and 12. However, on prolonging the reaction time to 3 h for 8 b, the major product is 5‐tert‐butyl‐8‐hydroxy[2.2]MPCP 10. These reactions are strongly affected by the size and properties of the C‐8 substitutents as well as the methyl substitutents on the para‐linked benzene rings, which increase the strain in the molecules. The 1H NMR spectra and X‐ray crystallographic analysis of 8 b revealed that it adopts a syn‐conformation both in solution and in the solid state.

Pressure-Dependent Structural and Luminescence Properties of 1-(Pyren-1-yl)but-2-yn-1-one.

The crystal structure of 1-(pyren-1-yl)but-2-yn-1-one (, a polynuclear aromatic hydrocarbon displaying enhanced luminescence in the solid state, has been re-determined at several pressures ranging from atmospheric up to 3 GPa using a Diamond Anvil Cell (DAC). These experiments were augmented by periodic DFT calculations at pressures up to 4.4 GPa. UV-Vis fluorescence of at non-ambient pressures has also been investigated. The crystal structure consists of infinite -stacks of anti-parallel molecules with discernible dimers, which may exemplify aggregates formed by pyrene derivatives in solution and thin films, and is predominantly stabilized by dispersion. The average inter-planar distance between individual molecules within -stacks decreases with pressure in the investigated range. This results in piezochromic properties of : a red-shift of sample color, as well as a bathochromic shift of fluorescence with pressure (by ca. 100 nm at 3.5 GPa). Two-component fluorescence spectra support the hypothesis that at least two types of excimers are involved in the electronic excitation processes in crystalline .

Synthesis of Fluoro and Cyanoaryl‐Containing Pyrene Derivatives and their Optical and Electrochemical Properties

AbstractMono‐ and 1,6‐disubstituted pyrene derivatives bearing perfluorotoluene or perfluorobenzonitrile moieties were synthesized by nucleophilic substitution processes. The compounds were characterized by NMR, UV‐vis, photoluminescence (PL), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), cyclic voltametry (CV) and density functional theory (DFT) calculations. It was found that derivatives substituted with perfluorobenzonitrile showed better thermal stability, stronger electron withdrawing ability and better fluorescence properties than the corresponding perfluorotoluyl‐pyrene systems

Strategic design and synthesis of AIEE (Aggregation Induced Enhanced Emission) active push-pull type pyrene derivatives for the ultrasensitive detection of explosives

Tuning of solid and solution phase emission with simple push-pull ‘Aggregation Induced Enhanced Emission’ (AIEE) pyrene compounds for deeper understanding on the mechanism for selectivity and sensitivity towards the nitro explosives with lowering the detection limit upto ppt (parts per trillion) level.

A pyrene based colorimetric chemosensor for CO2 gas detection triggered by fluoride ion

A pyrene derivative (KB-3) was synthesized and demonstrated as a colorimetric and ratiometric chemosensor for selective detection of fluoride ion with the detection limit of 391 nM. The mechanism of fluoride ion detection is due to the complete deprotonation of NH proton in KB-3 as revealed by 1H NMR studies. Further, the deprotonated KB-3 is demonstrated for perceptive detection of CO2 gas down to 0.1 ml. Moreover, detection of fluoride using KB-3 is explored to develop INHIBIT type logic gate at molecular level.

Highly Efficient Blue Organic Light-Emitting Diodes Based on Diarylamine-Substituted Pyrene Derivatives.

In this study, we designed and synthesized three blue fluorescence materials based on diarylamine-substituted pyrene derivatives. Organic Light Emitting-Diodes devices using these materials were fabricated in the following sequence; ITO/2-TNATA (300 Å)/NPB (200 Å)/α,β-ADN: 10 wt% blue materials 1-3 (300 Å)/DNAB (300 Å)/Liq (20 Å)/Al (1000 Å). All devices showed highly efficient blue emissions. Particularly, a device using materials (3) shown highly efficient blue emission with luminous efficiency of 8.94 cd/A, power efficiency of 4.40 lm/W, external quantum efficiency of 6.62% at 20 mA/cm², respectively, and the CIE coordinates of (0.16, 0.23) at 6.0 V.

Selective turn-on sensing of Cu2+ and Cl− by a ferrocene-modified pyrene derivative

Detection of metal ions and anions by fluorescent turn-on sensors are attractive and challenging. In this work, we designed and synthesized a ferrocene-modified bispyrene derivative, DPFc, as a fluorescent turn-on sensor to detect both Cu2+ and Cl−. The probe has good fluorescence stability in acetonitrile and can form an intramolecular excimer. When Cl− is present in the system, the addition of Cu2+ could effectively enhance the fluorescence of the probe, and the turn-on response to Cu2+ is selective by comparison with other metal ions. The probe also shows selective responses to Cl− over other type anions when an inert copper salt is present. The fluorescent turn-on responses to Cu2+ is attributed to the oxidation of Fe(II) in the ferrocene unit into Fe(III) by Cu2+ that prohibits the electron transfer-induced fluorescence quenching. UV–vis absorption measurements revealed that the presence of Cl− helped to bind with the probe and realized the oxidation of ferrocene unit by Cu2+. The present sensor could be used as a selective turn-on sensor for both Cu2+ and Cl−.