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A series of carbazole based sensitizers with either phenyl based donors (TBC, TMC, OMC, PC, TBR, TMR, OMR and PR) or aryl amine based donors (OMNC, CNC and HNC) as well as one without a donor group (CC) have been synthesized to understand the influence of the strength of the donor moiety on the optical, electrochemical and photovoltaic properties. Two different acceptor moieties such as cyano acrylic acid and rhodanine acetic acid were introduced and evaluated. Different substituents on the phenyl group have a significant impact on the light harvesting ability of the sensitizers. Among phenyl based donors, anisole based carbazole (OMC) shows the highest short circuit current (JSC) of 4.96 mA cm-2 with overall power conversion efficiency (PCE) of 2.69%. In the case of the sensitizers with aryl amine based donors, the increasing bulkiness of the donor group lead to increasing open circuit potential. Transient photocurrent and photovoltage measurements signify the importance of a bulky donor fragment in determining the open circuit potential of the dyes. Sensitizers with hexyloxy substituted phenyl amine as the donor group shows a JSC of 6.84 mA cm-2 with PCE of 3.33%. The overall investigation provides vital information about the influence of donor groups on the optoelectronic properties of the sensitizers for its photovoltaic applications.

Three-photon absorption (3PA) properties of symmetric-type carbazole derivatives show great potential for application in light-activated therapy and optical limiting. A novel symmetrical carbazole derivative (abbreviated as POCP) with end-groups of 1,10-phenanthroline rings as the donor moieties, chained via carbon-nitrogen (C = N) double bond, has been synthetized and its three photon absorption properties has been also determined by using a Q-switched Nd: YAG laser pumped with 30 ps pulses at 1064 nm in dimethylformamide. The measurement of 3PA cross-section of this compound is performed by open aperture Z-scan and σ3PA is 481 × 10-78 cm6 s2/photon2 for the transition S0 → S 1. The influence of the molecular structure of this compound on three-photon absorption cross-sections is discussed micromechanically by Austin model 1 and Zerner's Intermediate Neglect of Differential Overlap/S method. Copyright

[Rh(NBD)CL]2 catalyst was used to prepare poly(N-n-octyl-3- carbazoyl)acetylene, p(NOCzA) in the presence of various solvents at room temperature to selectively produce the corresponding cis-transoid polymer in high yields. The poly(NOCzA)s obtained were characterized in detail using analytical methods. The yellow or orange color of the polymers was ascribed to formation of the columnar as the π-conjugated self assembly whose content could also be decreased with compression associated with a red shift of the absorption maximum in the UV vis spectrum. The correlation between the absorption maximum in the conjugated polymer with the ionization potential was also described.

A series of quinoline derivatives containing bithiophene and N-octyl-carbazole moieties and a variety of substituents in the quinoline core were synthesized and characterized. The influence of bithienyl and N-octyl-carbazyl substituents on the photophysical properties of novel quinolines were thoroughly investigated and supported by DFT calculations. The absorption and emission maxima of quinolines are located at 373-412 and 410–606?nm, respectively, which considerably red-shifts when an electron-withdrawing substituent (NO2) is introduced to the quinoline ring. The quantum yield and lifetime for carbazyl-substituted quinolines are considerably higher (Φem?=?9–70%, τ?=?0.83–5.72?ns) compared to their bithiophene substituted counterparts (Φem?=?18–53%, τ?=?0.61–1.46?ns) resulting from greater planarity of carbazyl-substituted quinolines as proved by theoretical calculations. The carbazyl functional group in quinolines has immense impact on values of Δμ (13.83–15.50 D) indicating that the electron-donating ability of carbazole moiety relative to bithiophene motif (Δμ?=?9.16–13.83) in studied quinolines is more predisposed to intramolecular charge transfer (ICT). The capability of the novel compounds for cellular staining was investigated. All examined quinoline derivatives penetrate cell organelles quickly and efficiently with good overall fluorescence and signal to noise ratio. Relative lack of toxicity make them useful in such applications.

Although a diverse range of chemical entities offering striking therapeutic potential against urease enzyme has been reported, the key challenges (toxicity and safety) associated with these inhibitors create a large unmet medical need to unveil new, poten

A hybrid carbazole hemicyanine dye (receptor CHD) was developed as a new visible and near infrared chemodosimeter type sensor with high ratiometric selectivity towards cyanide in the presence of other anions in aqueous solution. The chemosensor also showed excellent performance when used in the "dip stick" method, i.e. in solid phase (TLC plates). The Royal Society of Chemistry 2013.

Two simple semiconducting acceptor-acceptor1-donor-acceptor (A-A1-D-A) modular, small molecule non-fullerene electron acceptors, 2-(4-(7-hexadecyl-1,3,6,8-tetraoxo-3,6,7,8-tetrahydrobenzo[lmn][3,8]phenanthrolin-2(1H)-yl)phenyl)-3-(6-

Due to their optical and electro-conductive attributes, carbazole derivatives are interesting materials for a large range of biosensor applications. In this study, we present the synthesis routes and fluorescence evaluation of newly designed carbazole fluorosensors that, by modification with uracil, have a special affinity for antiretroviral drugs via either Watson-Crick or Hoogsteen base pairing. To an N-octylcarbazole-uracil compound, four different groups were attached, namely thiophene, furane, ethylenedioxythiophene, and another uracil; yielding four different derivatives. Photophysical properties of these newly obtained derivatives are described, as are their interactions with the reverse transcriptase inhibitors such as abacavir, zidovudine, lamivudine and didanosine. The influence of each analyte on biosensor fluorescence was assessed on the basis of the Stern-Volmer equation and represented by Stern-Volmer constants. Consequently we have demonstrated that these structures based on carbazole, with a uracil group, may be successfully incorporated into alternative carbazole derivatives to form biosensors for the molecular recognition of antiretroviral drugs. The Author(s) 2011. This article is published with open access at Springerlink.com.

Lipid raft is a microdomain being rich in cholesterol and sphingolipid and closely related to neurodegenerative diseases such as Alzheimer’s disease and prion disease. Hence the study on the physiological mechanism of lipid raft is helpful to reveal its biological role and its correlations with diseases. Two-photon fluorescence probe for lipid raft is a sharp tool to achieve this goal. A dicyanocarbazolylstilbene-derived two-photon fluorescence probe for lipid raft (DLR) was developed. Both DLR and lipid raft belong to D-π-A (donor-π-acceptor; π: C = C) type rigid planar molecule, and contain four fused carbon rings (one five-membered ring and three six-membered ring), and bear a long carbon chain (C8H17). The excellent comparability between the rigid plane of the probe molecule and the rigid lipid raft could significantly enhance the specific affinity to lipid rafts. DLR’s maximum emission wavelength increased with medium polarity while its fluorescence intensity (FI) augmented with viscosity, and FI in DPPC (dipalmitoylphosphatidylcholine) was 20 times higher than that in DOPC (dioleoylphosphatidylcholine). DLR’s fluorescence lifetime in DPPC was more than 2.2 times longer than that in DOPC. These indicate that DLR can distinguish DPPC from DOPC. Φδs of DLR in DPPC and DOPC were 1350 GM and 67 GM, respectively. DLR can image lipid raft distribution in cells and tissues. Graphic abstract: [Figure not available: see fulltext.]

The developmen of donor-acceptor (D-A) architecture based organic chromophores with large two-photon absorption (2 PA) cross-sections are essential for myriad of applications, ranging from nonlinear microscopy to biomedical imaging. Here, we present the results from a comprehensive study of 2 PA cross-sections of a new series of carbazole mono substituted-π-conjugated-2,2′-bipyridine derivatives with D-π-A architecture, possessing carbazole as the donor moiety and bipyridine core as an acceptor. Further, we have extended the π-conjugation by introducing the phenyl and butoxy substituted phenyl linkers. The fluorescence properties of these D-A chromophores are highly sensitive to solvent polarity and alteration of electron donor functionalities. The relevant computation studies support our experimental results, e.g., a shift in emission maxima and band gaps of the molecules. The third-order nonlinear optical (NLO) properties of the title donor-acceptor (D-A) chromophores demonstrated that 2 PA cross-section values are in the range of 6–39 GM, obtained using ~50 fs (fs) laser pulses at a wavelength of 800 nm. Further, the nonlinear refractive indices (n2) of these chromophores were found to be ~10?14 cm2/W, rendering them potential optical switching candidates since the coefficients were obtained with kHz, fs pulses extracting pure electronic nonlinearities. Based on our experimental findings and theoretical calculations presented in this study, we believe that carbazole-based π-conjugated 2,2′-bipyridines, demonstrated in this work, would be potential ligands to obtain a series of transition metal coordination complexes of interesting physical properties (for example, superior NLO behaviour).

Both carbazole and pyrene are electron-rich aromatic systems and are expected to be potential donors when used in a push-pull dye architecture in the field of DSSC technology. Herein, two novel pyrene-carbazole dyes bearing single bond (PC1) and double bond (PC2) linkers and cyano-acrylic acid as an acceptor were synthesized. The dye with a double bond spacer (PC2) in the presence of CDCA achieved an improved power conversion efficiency of 6.30% with a short circuit current of 11.59 mA cm-2, open circuit potential (VOC) of 0.80 V, and a fill factor of 0.68 under standard global AM 1.5G solar conditions. Cyclic voltammetry and density functional theory studies indicate that the incorporation of two donors improved the ease of oxidation of the dyes, which resulted in a high VOC. Despite having a rigid single bond, the charge transfer of the PC1 dye is found to be poor, which affected the photovoltaic performance. The dihedral angle measured at each joint of the optimized dye indicated that PC2 exhibits excellent intramolecular charge transfer due to the near planarity in the structure. Besides, the high electron lifetime in the excited state of PC2 makes it the best performer among the three dyes studied.

Mechanoluminescence (ML) materials are environmentally friendly and emit light by utilizing mechanical energy. This has been utilized in light sources, displays, bioimaging, and advanced sensors. Organic ML materials are strongly limited to application by in situ unrepeatable ML. Now, in situ solar-renewable organic ML materials can be formed by introducing a soft alkyl chain into an ML unit. For the first time, the ML from these polycrystalline thin films can be iteratively produced by simply recrystallizing the fractured crystal in situ after a contactless exposure to sunlight within a short time (≤60 s). Additionally, their ML color and lifetime can be also easily tuned by doping with organic luminescent dyes. Therefore, large-area sandwich-type organic ML devices can be fabricated, which can be repeatedly used in a colorful piezo-display, visual handwriting monitor, and sensitive optical sensor, showing a lowest pressure threshold for ML of about 5 kPa.

The invention belongs to the technical field of fine chemical engineering, and particularly relates to a preparation method of a two-photon fluorescence pH probe and application in cell imaging thereof. The probe is prepared by taking dicyan-biphenyl-ethylene as a matrix, and comprises carbazolyl, di-cyano and n-octyl. Because the molecular structure of the probe has a longer flexible chain, the lipophicity is stronger, the probe can penetrate a cell wall (or cell membrane) into a cell to stain the cell for detecting the pH in the cell; the molecular structure of the probe belongs to D-pi-A type molecules, the two-photon absorption cross section (delta) is improved, so that the probe has higher imaging definition and resolution; in addition, the probe has a large Stokes shift in the marking process, thereby greatly improving the imaging accuracy and precision; the fluorescence quantum yield (phi) of the probe in a solvent is higher, the two-photon emission cross section is larger, so that the higher the brightness of the imaging is, the clearer the image is, and the higher the resolution is.

In this study, newly substituted carbazole derivatives of S1; (Z)-4-((9-isobutyl-9H-carbazol-3-ylimino)methyl)phenol, S2; (Z)-9-butyl- N-(2,3,4-trimethoxybenzylidine)-9H-carbazol-3-amine, S3; (Z)-4-((9-octyl-9H-carbazol-3-ylimino)methyl)benzene-1,2-diol and S4; (Z)-3-((9-octyl-9H-carbazol-3-ylimino)methyl)benzene-1,2-diol compounds are synthesized by using condensation reaction between carbazole amines and aromatic aldehydes. All synthesized carbazole Schiff bases are purified by crystallizing from chloroform. The structural and optical characterizations of synthesized compounds are investigated by FT-IR (Fourier Transform-Infrared Spectroscopy), 1H NMR (Proton Nuclear Magnetic Resonance), 13C NMR (Carbon Nuclear Magnetic Resonance), LC-MS (Liquid Chromatography-Mass Spectrometry) and temperature dependent PL (Photoluminescence) measurements. The formations of synthesized Schiff bases were confirmed by FT-IR, NMR and microanalysis. Due to stronger π-conjugation and efficient charge transfer from host material, the broad and complex bands centered at about ～2.16 and ～1.76 eV are observed in PL spectra for all samples. Their relative intensities depend on functional groups associated with the carbazole. These newly synthesized Schiff bases could be considered as an active emissive layer for organic light emitting diodes.

The invention relates to a preparation method of photoinitiator of benzophenone oxime acetate containing dicarbazole. Carbazole and 1-bromooctane react in potassium hydroxide and DMSO system, and a midbody I is obtained; the midbody I is subjected to a nitration reaction with nitric acid, and a midbody II is obtained; under the catalysis effect of alchlor, the midbody II is subjected to a Friedel-Crafts reaction with 4,4'-oxydibenzoyl chloride, and a midbody III is obtained; under the condition of a mixed solvent of DMF (dimethyl formamide)-water, the midbody II reacts with hydroxylamine hydrochloride, and a midbody IV is obtained; and finally the midbody IV reacts with acetic anhydride, and the target compound, that is, the photoinitiator of benzophenone oxime acetate containing dicarbazole is obtained. The preparation method is easy to operate, the technology is advanced, the solvent can be recycled and reused, and the preparation method is easy to be put into industrialized production.

Novel 2,4,6-triphenyl-1,3,5-triazine linked carbazole through olefin double bond star shape molecules with different linear and branched chain were synthesized and systematically investigated by aggregation induced emission (AIE) studies and electrochemical properties. These molecules are shows broad absorbance range with good intramolecular charge transfer character (ICT). These derivatives are exhibit positive solvatochromism effect and higher Stokes shift values in the range of 6819–1119?cm?1. These derivatives are displayed aggregation-induced emission (AIE) property in THF-water mixture (TRZ-hexyl at 10/90%, TRZ-octyl at 30/70%, TRZ-branched at 50/50%). The electrochemical studies show that band gap of TRZ-hexyl, TRZ-octyl, and TRZ-branched at 1.87, 1.73?eV, and 1.86?eV respectively. All these derivatives are exhibit deep-lying highest occupied molecular orbital (HOMO) energy levels at?～??5.04?eV and LUMO energy levels at?～??3.20?eV. The proper AIE, HOMO, and LUMO energy level pave the way for their potential use in OLEDs and solar cell applications.

The invention discloses novel 3, 5-position styryl-bridged BODIPY dyes and a preparation method thereof. The novel 3, 5-position styryl-bridged BODIPY dyes I are prepared by first performing Suzuki coupling on halogenated fluorene, carbazole, phenothiazine and other groups and p-formylbenzeneboronic acid under the catalytic action of tetrakis(triphenylphosphine palladium) to obtain corresponding aldehyde with a donor unit, and then performing Knoevenagel condensation on the corresponding aldehyde and a BODIPY unit under the action of piperidine. A synthesis method of the novel 3, 5-position styryl-bridged BODIPY dyes I is simple; the reaction condition is easy to control; the novel 3, 5-position styryl-bridged BODIPY dyes have universal applicability, can be widely applied to the scientific fields of energy, life, analysis, materials and the like, and are especially suitable to be used as organic small molecule solar cell donor materials.

A multibranched carbazole linked triazine centre based molecule (TRZ-Cz) was synthesized using the Wittig-Horner reaction and used as a fluorescent probe for the detection of picric acid (PA). The thermally more stable alkylated carbazole moiety was purposely introduced into TRZ-Cz, and could play a significant role in enhancing the thermal stability and solubility, reducing the steric hindrance, and increasing the intramolecular charge transfer (ICT) between the carbazole donor and the triazine acceptor moiety. In this paper, we employed the TRZ-Cz molecule in the detection of different nitroaromatic compounds (NACs). Among these various NACs, hydroxyl containing nitro compounds are effectively quenched; this may be due to the π-π interactions between TRZ-Cz and the acidic phenolic hydroxyl groups. The TRZ-Cz molecule exhibits a high quenching response to PA with high sensitivity and selectivity, compared to other analytes. TRZ-Cz shows good aggregation-induced emission (AIE) effects in a H2O/THF (7?:?3 v/v) mixture and these aggregates are also able to detect PA. This study offers details for the design and preparation of a new multibranched molecular fluorescent probe for the detection of PA, with low toxicity, easy synthesis steps, and high selectivity.

The invention discloses a boron fluoride complexing bi-pyrrole methylidyne derivative substituted by meso-position alkyl thiophene and a 3,5-position electron-donating group and a preparation method of the derivative. According to the method, 2-bromothiophene serves as a starting raw material, dipyrrylmethanes substituted by meso-position alkyl thiophene is synthesized through a series of reactions, NBS bromination is conducted, and 3,5-dibromo bi-pyrrolidine is obtained; then, TCQ oxidation and boron trifluoride ether complexing are conducted, a 3,5-boron dibromo fluorine intermediate with the meso-position containing alkyl thiophene is obtained, then the intermediate is utilized to conduct an Suzuki/Stille coupled reaction with a variety of modification groups, the boron fluoride complexing bi-pyrrole methylidyne derivative substituted by a 3,5-position donor unit is obtained, and the structural formula can be found in formula I. The boron fluoride complexing bi-pyrrole methylidyne derivative substituted by meso-position alkyl thiophene and the 3,5-position electron-donating group has good stability and has potential application value in the fields of life science, solar cells, environment, energy and the like.

The present invention relates to a novel 2,6-site-substituted BODIPY organic dye sensitizer and a preparation method therefor. The organic dye sensitizer is organic photovoltaic materials with a D-pi-A structure. By taking a meso-site-substituted BODIPY core as a pi bridge framework, the sites 2 and 6 of the BODIPY core is respectively substituted by an electron donor and an electron acceptor. The present invention further discloses a preparation method for the above the dye sensitizer. The preparation method obtains a dye molecule having a general structural formula I by taking 2,4-dimethylpyrrole as an initial reaction raw material, performing a serials of simple synthesis reactions, and finally performing classical Suzuki coupling and Knoevenagel condensation reactions. The dye sensitizer synthesis method is simple, easy to control and high in yield, and has general applicability. When the method is applied to dye sensitized solar cell preparation, a dye sensitized solar cell material with a high fill factor and an ideal photoelectric conversion efficiency can be obtained. The formula I is shown in the description.

The invention discloses a median alkoxy phenyl substituted and 2, 6 site strong electron donating group substituted BODIPY (4,4'-difluoro-4-bora-3a,4a-diaza-sindacene) derivative and a preparation method thereof. The preparation method comprises: synthesizing a median alkoxy phenyl substituted 2, 6-dibromo fluorine boron intermediate through a series of reactions; and performing Suzuki/Stille coupling reaction by using the intermediate and a variety of modified groups to obtain a median alkoxy phenyl substituted and 2, 6 site thiofuran, thienothiophene, fluorene, carbazole and other strong electron donating units substituted BODIPY derivatives. The absorption spectrum of the prepared target dye molecules generates obvious bathochromic shift, and the maximum absorption wavelength is lengthened to a near infrared area. The median alkoxy phenyl substituted and 2, 6 site strong electron donating group substituted BODIPY derivative has good stability, and has potential application values in the fields of life sciences, solar batteries, environment energy sources and the like.

A series of novel carbazole aminothiazoles as a new type of antimicrobial agents were designed, synthesized and characterized by 1H NMR, 13C NMR, IR, MS and HRMS spectra. Some of the carbazole aminothiazoles exhibited good antimicrobial activities; particularly, heptyl-derived carbazole aminothiazole 4f could effectively inhibit the growth of MRSA with an MIC value of 4 μg mL-1, which was superior to the reference drugs Chloromycin and Norfloxacin. Moreover, cytotoxicity investigation indicated that bioactive compound 4f did not exhibit cytotoxicity to Hep-2 cells within its MIC against MRSA. Preliminary interactive investigation revealed that compound 4f could effectively intercalate into calf thymus DNA to form 4f-DNA complexes which might block DNA replication and thus exert antimicrobial activities. In addition, the binding behavior of compound 4f to DNA revealed that compound 4f could interact with DNA by hydrogen bonds and electrostatic interactions.

Reported herein are six novel metal free organic dyes such as PCA1-PCA3 and PCTA1-PCTA3 featuring fused heterocyclic structural motifs such as phenothiazine and alkylcarbazole. Photophysical/electrochemical properties and nanocrystalline TiO2 based dye-sensitized solar cell performance of the same have been investigated. Electronic distribution within the molecules has been determined through a computational approach. The overall power conversion efficiencies of the devices with the utilization of dyes PCA1-PCA3 and PCTA1-PCTA3 as sensitizers ranges between 4.67 and 8.08%. The novel dyes possessing cyanoacrylic acid as electron acceptor, PCA1-PCA3, exhibit higher power conversion efficiency, short-circuit current, open-circuit voltage, and electron lifetime those with thioxothiazolidinylacetic acid, PCTA1-PCTA3, as the same. Of the devices fabricated by employing the new metal-free organic sensitizers, that with the dye PCA2 exerted a power conversion efficiency (PCE, η) of 8.08% with a short circuit current density (JSC) of 16.45 mA cm-2, an open circuit voltage (VOC) of 735 mV and a fill factor (ff) of 0.68; this PCE is the highest amongst the devices fabricated.

Two benzo(1,2-b:4,5-b′)dithiophene (denoted as BDT) based organic dyes, Dye 1 and Dye 2, containing triphenylamine and carbazole in the molecular frameworks respectively, were synthesized, characterized and applied in dye-sensitized solar cells (DSSCs). The photo-physical, photovoltaic, and electrochemical properties of the two dyes were analyzed in this work. The two dyes exhibit strong charge transfer absorption bands in the visible region. The dyes were applied in dye sensitized solar cells obtaining 11.34 mA/cm2, 0.75 V and 0.74, for the short-circuit photocurrent density (Jsc), open-circuit voltage (Voc), and fill factor (FF) respectively, corresponding to an overall power conversion efficiency of 6.3%. These results revealed that BDT-based dyes are promising dyes for DSSCs.

A series of new molecular materials with varying carbazole and fluorene contents were prepared employing Suzuki coupling and their properties were compared. A variation of the core nucleus from fluorene to carbazole was a key point to study its effect on the thermal, optical and electrochemical properties. The materials were characterized by FTIR, 1H-, 13C-NMR, APCI-MS and elemental microanalyses. The synthesized materials exhibit slightly bathochromic shifted UV/Vis spectra in dilute solution and emission maxima in the blue region along with good thermal stability. The dyes with a fluorene core are electrochemically and spectrally stable with high lying HOMO levels, in contrast to the carbazole only materials, having potential as light emitting and hole transporting materials in organic light emitting diodes.

The N-arylation of various amines with aryl chlorides proceeded in good-to-excellent yields in the presence of P[N{(p-NMe2)C6H4CH2}CH2CH2]3N (1e, a new electron-rich proazaphosphatrane ligand) and small amounts of Pd2(dba)3 (dba = dibenzylideneacetone). This catalytic system was also very effective for the synthesis of carbazoles. An efficient palladium-catalyzed N-arylation reaction of amines under mild conditions with a tuned bicyclic proazaphosphatrane has been developed.

By using Heck polycondensation, we have synthesized carbazole-based alt-copolymers tethered with polyhedral oligomeric silsesquioxanes (POSS), which had well-defined architectures, similar polymerization degrees and the different contents of POSS. The effect of POSS content and the length of the side chain containing POSS on the electroluminescence properties of these polymers were investigated. POSS particles in these alt-copolymers showed excellent dispersity and prevented the interchain aggregation of polymers in film state well. Besides, POSS benefited charge balance by increasing the electron current density, which led to a higher luminance and current efficiency, as well as purer blue light-emitting.

Three novel donor-π-acceptor (D-π-A) type chiral polymers P1, P2, and P3 could be synthesized from diiodo-substituted chiral boron-dipyrromethene (BODIPY) derivative (M-1) with 2,7-diethynyl-9,9-dioctyl-9H-fluorene (M-2), 3,6-diethynyl-9-octyl-9H-carbazol

A series of 4-nitrophenylacrylonitrile and phenylacrylonitrile derivatives consisting of a carbazole moiety was synthesized. Some of these derivatives with longer alkyl chains and a nitro group could gelatinize some organic solvents, such as ethanol, n-butanol, ethyl acetate, and DMSO. By contrast, phenylacrylonitrile derivatives did not form gels in measured solvents. This result proved that the electron-withdrawing nitro moiety was important for gel formation because it conferred the molecules with large dipole moments, which enhanced the intermolecular interaction. Analyses by UV-vis absorption, X-ray diffraction, and scanning electron microscopy showed that the gelator molecules could self-assemble into one-dimensional nanofibers with layer packing, which further twisted into thicker fibers and formed three-dimensional networks in the gel phase. The single crystal structure of C4CNPA implied that the gelators might adopt an anti-parallel molecular stacking because of their larger ground-state dipole moment. Interestingly, the organogels had enhanced fluorescence relative to solutions at the same concentrations. This journal is the Partner Organisations 2014.

Two new thermally crosslinkable hole-transporting polymers, X-PTPA and X-PCz, were synthesized via Yamamoto coupling reactions. The number-averaged molecular weights (Mn) of X-PTPA and X-PCz were found to be 45,000 and 48,000, respectively, and therewith, polydispersity indices were of 1.8 and 1.7, respectively. Thermally crosslinked X-PTPA and X-PCz exhibit excellent solvent resistance and stable optoelectronic properties. The UV-visible maximum absorption peaks of X-PTPA and X-PCz in the thin film state are at 389 and 322 nm, respectively. The HOMO levels of X-PTPA and X-PCz are estimated to be -5.27 and -5.39 eV, respectively. Multilayered devices (ITO/crosslinked X-PTPA or X-PCz/SY-PPV/LiF/Al) were fabricated with SY (SuperYellow) as the emitting layer. The maximum efficiency of the multilayered device with a crosslinked X-PTPA layer is approximately three times higher than that of the device without a crosslinked X-PTPA layer and much higher than that of the crosslinked X-PCz device. This result can be explained by the observations that crosslinked X-PTPA produces increased electron accumulation within the emitter, SY, and also efficient exciton formation due to improved charge balance. Copyright

A novel carbazole-based conjugated polymer with tethered acetylenes, poly [(9,9-dioctyl)-2,7-fluorene-(N-octyl-3,6-carbazole)]-co-[(9,9-dioctyl)-2, 7-fluorene-(N-4-phenylacetylene)-3,6-carbazole)] (P-2), was successfully synthesized through the desilylati

A series of pyrene-centered starburst oligocarbazoles (1-3) have been synthesized and well characterized. Based on photophysical, thermal and electrochemical studies in solutions and as thin films, all starburst molecules reveal a sky blue emission with a high efficiency (ΦF = 0.99 - 0.81) and excellent thermal and electrochemical stabilities. As OLED materials, these superior properties are helpful to enhance device stability and lifetime.

The synthesis, as well as spectroscopic and thermochemical studies of a novel class of carbazole-4-phenylpyridine co-polymers are described. The synthesis was carried out by a simple and cheaper method compared to the lengthy methods usually adopted for the preparation of carbazole-pyridine copolymers which involve costly catalysts. Thus, two series of polymers were synthesized by a modified Chichibabin reaction, i.e., by the condensation of diacetylated N-alkylcarbazoles with 3-substituted benzaldehydes in the presence of ammonium acetate in refluxing acetic acid. All the polymers were characterized by FTIR, 1H NMR, 13C NMR, UV-vis spectroscopy, fluorimetry, TGA and DSC. The weight average molecular masses (Mw) of the polymers were estimated by the laser light scattering (LLS) technique.

A series of new triphenylamine-functionalized bis(β-diketone)s bridged by a carbazole (CnBDKC, n=1, 4, 8, 16) with twisted intramolecular charge-transfer emission in polar solvents has been synthesized. The length of the carbon chains has a significant effect on the self-assembling properties of the compounds. Well-defined 1D nanowires were easily generated from C1BDKC with a methyl group by a reprecipitation approach directed by π-stacking interaction, and the molecules packed into J-aggregates in the nanowires. In addition, 1D nanofibers based on C16BDKC bearing a long hexadecyl chain were prepared through the organogelation process, and H-aggregates were formed driven by the synergistic effect of π-stacking interaction and van der Waals force in the gel phase. C4BDKC and C8BDKC containing butyl and octyl side chains, respectively, cannot arrange into dispersed nanostructures, probably because π-π interaction between conjugated moieties might be disturbed by the interaction between the side chains, which is, however, not strong enough to dominate the self-assembling process. Notably, the nanowires based on C1BDKC and the gel nanofibers from C16BDKC can emit strong green light under irradiation, which suggests that these 1D nanomaterials may have potential applications in emitting materials as well as photonic devices. Given the green light: Well-defined 1D nanowires and nanofibers have been fabricated by reprecipitation and organogelation from triphenylamine-functionalized bis(β-diketone)s bridged by carbazole with alkyl chains of different length (CnBDKC, n=1, 16, respectively; see picture). The nanostructures give strong green fluorescent emission.

To exploit an effective way to improve polymeric photovoltaic performance, a series of dithiophene-benzothiadiazole-alt-fluorene copolymers containing carbazole groups at C-9 positions of the alternating fluorene units (PFO-FCz-DBT) were synthesized and characterized. The effect of the carbazole groups on the optophysical, electrochemical, and photovoltaic properties of these copolymers was investigated. By comparison, this type of copolymers with carbazole units exhibited significantly improved photovoltaic properties than poly(2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4′,7′-di-2-thienyl- 2′,1′,3′-benzothiadiazole) (PFO-DBT) in the bulk heterojunction solar cells. A maximum power-conversion efficiency (PCE) of 2.41% and a highest short-circuit current density (Jsc) of 9.68 mA cm -2 were obtained for the PFO-FCz-DBT30, which are about two times higher than the corresponding levels for the PFO-DBT30. This work demonstrated that introducing a hole-transporting carbazole unit into copolymer is a simple and effective method to improve the Jsc and PCE. Copyright

The invention aims at providing a photovoltaic device with high photoelectric conversion efficiency. The aim is attained by an electron donating organic material containing a benzothiadiazole compound in which (a) a benzothiadiazole skeleton and an oligothiophene skeleton are contained, (b) a band gap (Eg) is 1.8 eV or less, and (c) the level of the highest occupied molecular orbital (HOMO) is -4.8 eV or less, wherein said benzothiadiazole compound is formed by covalently combining the benzothiadiazole skeleton and the oligothiophene skeleton alternately, the proportion between the benzothiadiazole skeleton and the oligothiophene skeleton is within a range of 1:1 to 1:2 (however, excluding 1:1), and the number of thiophene rings contained in an oligothiophene skeleton is 3 or more and 12 or less.

A highly efficient one-pot synthesis of carbazoles via palladium-catalyzed double N-arylation of primary amines with 2,2'-dihalobiphenyls is described using a catalyst system comprised of tris(dibenzylideneacetone)dipalladium(O) (Pd2dba3) and the proazaphosphatrane P(i-BuNCH 2CH2)3N (8) or its derivative (t-Bu) 2P=N-P(iBuNCH2CH2)3N (9a) as the ligand. The process is effective for double N-arylation of 2,2'-biphenyl dibromide, diiodide, and even dichloride with a variety of primary amines including neutral, electronrich, electron-deficient, and sterically hindered anilines as well as aliphatic amines.

The one-step construction of N-substituted carbazoles by way of the Pd-catalyzed double N-arylation reaction of primary amines with 2,2′-dibromobiphenyl is described. Aryl and aliphatic amines including tert-butylamine and a protected glucopyranosylamine were effectively transformed into the corresponding N-substituted carbazoles. The first total synthesis of murrastifoline-A, a biscarbazole alkaloid, based on this methodology is also presented.

A series of novel carbazole compounds was synthesized and tested for their suitability as host for triplet emitters in an organic-light emitting diode (OLED). In these compounds, a carbazole unit is either connected to other carbazole units to form carbazole dimers and trimers or to fluorene and oxadiazole derivatives to form mixed compounds. The HOMO level of carbazole compounds can be tuned by substitution at the 3, 6, and/or 9 positions. Making oligomers by connecting carbazole molecules via their 3 (3′) positions shifts the HOMO level to higher energy, while replacing alkyl groups at the 9 (9′) positions by aryl groups shifts the HOMO level to lower energy. Furthermore, it has been found that the triplet energy of these compounds is determined by the presence of poly(p-phenyl) chains in the molecular structure. By identifying the longest poly(p-phenyl) chain, one can predict whether a compound will be a suitable host for a high-energy triplet emitter. An overview of HOMO levels, singlet and triplet levels, and exchange energies is given for all carbazole compounds synthesized. Finally, OLEDs employing two selected carbazole compounds as host and fac-tris(2-phenylpyridine)-iridium (Ir(ppy) 3) as guest were constructed and characterized electrically.

A powerful method: A variety of sterically crowded, substituted carbazoles have been prepared from anilines and biphenyl compounds (see scheme). The method enabled the preparation of 2,2′-dicarbazolyl-1,1′-biaryl compounds, which show excimer (or exciplex) emissions with significant solvent dependency.