Fluoranthene-Based Molecules as Electron Transport and Blue Fluorescent Materials for Organic Light-Emitting Diodes

Herein we report the synthesis, characterization, and potential application of bis­(4-(7,9,10-triphenylfluoranthen-8-yl)­phenyl)­sulfone (TPFDPSO2) and 2,8-bis­(7,9,10-triphenylfluoranthen-8-yl)­dibenzo­[<i>b</i>,<i>d</i>]­thiophene 5,5-dioxide (TPFDBTO2) as electron transport as well as light-emitting materials. These fluoranthene derivatives were synthesized by oxidation of their corresponding parent sulfide compounds, which were prepared via Diels–Alder reaction. These materials exhibit deep blue fluorescence emission in both solution and thin film, high photoluminescence quantum yield (PLQY), thermal and electrochemical stability over a wide potential range. Hole- and electron-only devices were fabricated to study the charge transport characteristics, and predominant electron transport property comparable with that of a well-known electron transport material, Alq₃, was observed. Furthermore, bilayer electroluminescent devices were fabricated utilizing these fluoranthene derivatives as electron transport as well as emitting layer, and device performance was compared with that of their parent sulfide molecules. The electroluminescence (EL) devices fabricated with these molecules displayed bright sky blue color emission and 5-fold improvement in external quantum efficiency (EQE) with respect to their parent compounds

Fluoranthene Based Derivatives for Detection of Trace Explosive Nitroaromatics

A series of fluoranthene derivatives (<b>F1</b>–<b>F5</b>) varied with nature and type of substituents were synthesized <i>via</i> Diels–Alder reaction followed by <i>in situ</i> decarbonylation. The solid state structures have been established through single crystal X-ray diffraction (XRD). The presence of extended conjugation and having two alkyloxy chains on phenyl rings induces flexibility to orient opposite to each other and interacts with another fluoranthene unit with weak π–π interactions and show unique supramolecular arrangements. The envisaged photophysical and DFT studies demonstrated that HOMO–LUMO levels were effectively tuned by different substituents with an optical band gap from 3.44 to 3.88 eV provoked to examine as sensitive fluorescent chemosensors for the detection of nitroaromatic compounds (NACs). The sensitivity toward the detection of NACs was evaluated through fluorescence quenching in solution (aqueous and non-aqueous) and solid state (vapor and contact mode). Fluorescence studies demonstrated that electron transfer occurs from the electron rich fluoranthene fluorophores to the electron deficient NACs by the dominant static quenching mechanism and the quenching process is reversible. It was found that the detection sensitivity increases with extent of conjugation on fluoranthene unit. The contact mode approach using thin layer silica chromatographic plates exhibits a femtogram (1.15 fg/cm²) detection limit for trinitrotoluene (TNT) and picric acid (PA), while the solution state fluorescence quenching shows for PA detection at the 2–20 ppb level. The sensing performance of fluoranthene thin films to NACs in aqueous solution reveals that fluorophores are highly selective towards the detection of PA. The smart performances of thin film fluorophores with high photostability have great advantage than those of conjugated polymers with superior sensitive detection of PA in groundwater

Correlation between Optical Properties and Nanomorphology of Fluoranthene-Based Conjugated Copolymer

Nanoparticles of conjugated polymers are receiving attention due to their interesting optical properties. Here we report nanoparticles of fluoranthene-based conjugated copolymer prepared by the Suzuki coupling reaction. The copolymer forms nanoparticles by the spontaneous self-assembly after evaporation of organic solvent. The mean diameter of the nanoparticles can be manipulated by varying solvent composition. We investigated the parameters that govern the nanostructured morphology of polymer by systematic variation of good and poor solvent. The UV–vis and time-resolved fluorescence spectroscopy measurement reveal the use of poor solvent in the organization of nanostructures. Furthermore, transmission electron microscopy highlights the importance of rigidity of the polymer backbone in morphological development

Fluoranthene Based Derivatives for Detection of Trace Explosive Nitroaromatics

A series of fluoranthene derivatives (<b>F1</b>–<b>F5</b>) varied with nature and type of substituents were synthesized <i>via</i> Diels–Alder reaction followed by <i>in situ</i> decarbonylation. The solid state structures have been established through single crystal X-ray diffraction (XRD). The presence of extended conjugation and having two alkyloxy chains on phenyl rings induces flexibility to orient opposite to each other and interacts with another fluoranthene unit with weak π–π interactions and show unique supramolecular arrangements. The envisaged photophysical and DFT studies demonstrated that HOMO–LUMO levels were effectively tuned by different substituents with an optical band gap from 3.44 to 3.88 eV provoked to examine as sensitive fluorescent chemosensors for the detection of nitroaromatic compounds (NACs). The sensitivity toward the detection of NACs was evaluated through fluorescence quenching in solution (aqueous and non-aqueous) and solid state (vapor and contact mode). Fluorescence studies demonstrated that electron transfer occurs from the electron rich fluoranthene fluorophores to the electron deficient NACs by the dominant static quenching mechanism and the quenching process is reversible. It was found that the detection sensitivity increases with extent of conjugation on fluoranthene unit. The contact mode approach using thin layer silica chromatographic plates exhibits a femtogram (1.15 fg/cm²) detection limit for trinitrotoluene (TNT) and picric acid (PA), while the solution state fluorescence quenching shows for PA detection at the 2–20 ppb level. The sensing performance of fluoranthene thin films to NACs in aqueous solution reveals that fluorophores are highly selective towards the detection of PA. The smart performances of thin film fluorophores with high photostability have great advantage than those of conjugated polymers with superior sensitive detection of PA in groundwater

Bioactive isoquinoline alkaloids from <i>Cissampelos pareira</i>^†

<p>The phytochemical and biological investigation of <i>Cissampelos pareira</i> leads to the isolation of one new isoquinoline alkaloid (<b>7</b>) along with six known isoquinoline alkaloids, namely, magnoflorine (<b>1</b>), magnocurarine (<b>2</b>), cissamine (<b>3</b>), curine (<b>4</b>), hayatinine (<b>5</b>) and cycleanine (<b>6</b>). Magnoflorine (<b>1</b>) and magnocurarine (<b>2</b>) were isolated for the first time from <i>C. pareira.</i> A new, rapid, simple and sensitive UPLC method was developed for simultaneous quantification of five pure compounds (<b>1</b>–<b>5</b>). Seasonal variation study revealed higher content of these compounds during the rainy season. The chloroform (CPCF) and <i>n</i>-butanol (CPBF) fractions showed cytotoxic efficacy against KB cells. Among pure compounds, hayatinine (<b>5</b>) was found to be most active against KB and A549, while, cycleanine (<b>6</b>) against KB cells.</p

List of the 73 EST and genomic SSRs primers used in present study.

<p>List of the 73 EST and genomic SSRs primers used in present study.</p

Source / Origin of 96 genotypes of lentil used in the study.

<p>Source / Origin of 96 genotypes of lentil used in the study.</p

Neighbour joining dendrogram of 96 genotype of lentil with 73 SSRs (Serial number of genotype in the figure corresponds with serial number and genotype in Table 1).

<p>Neighbour joining dendrogram of 96 genotype of lentil with 73 SSRs (Serial number of genotype in the figure corresponds with serial number and genotype in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0188296#pone.0188296.t001" target="_blank">Table 1</a>).</p

Linkage disequilibrium patterns among 96 genotypes genotyped with 73 SSRs.

<p>The squared correlation coefficients (r²) for each pair of markers are presented in the upper triangle and their corresponding p values in the lower triangle.</p

Manhattan plot depicting association of 73 SSRs markers with grain iron concentration for (A) Delhi (2013–14) (B) Dharwad (2013–14) (C) Indore (2013–14) (D) Delhi (2014–15) (E) Combined all location year.

<p>Manhattan plot depicting association of 73 SSRs markers with grain iron concentration for (A) Delhi (2013–14) (B) Dharwad (2013–14) (C) Indore (2013–14) (D) Delhi (2014–15) (E) Combined all location year.</p