Abstract  Clusters of phthalocyanine and phthalocyanine-perylene diimide have been prepared and electrophoretically deposited on nanostructured SnO2 electrodes. The structure and photoelectrochemical properties of the clusters have been investigated by using UV-visible absorption, dynamic light scattering (DLS), atomic force microscopy (AFM), transmission electron microscopy (TEM), and photoelectrochemical and photodynamical measurements. Enhancement of the photocurrent generation efficiency in the composite system has been achieved relative to that in the phthalocyanine reference system without the perylene diimide. Such information will be valuable for the design of molecular photoelectrochemical devices that exhibit efficient photocurrent generation.

Abstract  A bisthienylethene-functionalized perylene diimide (BTE-PDI) photochromic dyad was synthesized for self-assembly into 1-D nanotubes by a reprecipitation method. SEM and TEM observations showed that the nanotubes were formed from their 0-D precursors of hollow nanospheres. HR-TEM images revealed that both the nanospheres and the nanotubes have highly ordered lamellar structure, indicating the hierarchical process during assembly. The IR and XRD results revealed that DAE-PDI molecules were connected through intermolecular hydrogen bonds to form building blocks that self-assembled into nanostructures. Electronic absorption and fluorescence spectroscopic results indicated the H-aggregate nature of the self-assembled nanostructures. Competition and cooperation between the dipole-dipole interaction, intermolecular pi-pi stacking, and hydrophilic/hydrophobic interaction are suggested to result in nanostructures. Reconstruction was found to happen during the morphology transition progress from the 0-D nanospheres to the 1-D nanotubes, which was driven by donor-acceptor dipole-dipole interactions. Green emission at 520 nm originating from the DAE subunit was observed for the aggregates of vesicles and nanotubes, which could be regulated by photoirradiation with 365 nm light, suggesting the nanoaggregates to be photochromic switches.

Abstract  We demonstrate that thin films of metal-organic framework (MOF)-like materials, containing two perylenediimides (PDICl4, PDIOPh2) and a squaraine dye (S1), can be fabricated by layer-by-layer assembly (LbL). Interestingly, these LbL films absorb across the visible light region (400-750 nm) and facilitate directional energy transfer. Due to the high spectral overlap and oriented transition dipole moments of the donor (PDICl4 and PDIOPh2) and acceptor (S1) components, directional long-range energy transfer from the bluest to reddest absorber was successfully demonstrated in the multicomponent MOF-like films. These findings have significant implications for the development of solar energy conversion devices based on MOFs.

Abstract  We report a comparative study on the self-assembly from solution and electrical characterization of n-type semiconducting fibres obtained from five different perylenebis(dicarboximide) (PDI) derivatives. In particular we investigated the role of the nature of the alkyl chain covalently linked to the N,N' sites of the PDI in modulating the molecular solubility and aggregation capacity. We explored the morphologies of the self-assembled architectures physisorbed on dielectric surfaces and in particular how they can be modified by tuning the deposition and post-deposition procedures, i.e. by modulating the kinetics of the self-assembly process. To this end, alongside the conventional spin-coating, solvent vapour annealing (SVA) and solvent induced precipitation (SIP) have been employed. Both approaches led to fibres having widths of several hundred nanometres and lengths up to tens of micrometres. SVA formed isolated fibres which were tens of nanometres high, flat, and tapered at the ends. Conversely, SIP fibres exhibited nearly matching heights and widths, but organized into bundles. Despite these morphological differences, the same intermolecular packing is found by XRD in each type of structure, albeit with differing degrees of long-range order. The study of the electrical characteristics of the obtained low dimensional nano-assemblies has been accomplished by fabricating and characterizing organic field-effect transistors.

Abstract  A facile approach for introducing photoactive poly(fluorene-perylene diimide) arrays (PFPDI) onto graphene sheets was accomplished. Noncovalent PFPDI/graphene ensembles formed via π-π stacking interactions between the two components and covalent PFPDI-graphene hybrids realized upon a Stille polycondensation reaction between an iodobenzyl-functionalized graphene, a 9,9-dialkyl substituted fluorene diboronic acid, and a 1,7-dibromo-PDI derivative were prepared. The morphology of PFPDI/graphene and PFPDI-graphene was evaluated by high-resolution transmission electron microscopy (HR-TEM), revealing the presence of even monolayered graphene sheets. Moreover, their photophysical and redox properties as assessed by electronic absorption spectroscopy and steady-state as well as time-resolved photoluminescence assays and electrochemistry, respectively, disclosed charge-transfer characteristics owing to the high photoluminescence quenching of PFPDI in the presence of graphene and the fast component attributed to the decay of the emission intensity of the singlet excited state of PFPDI in both PFPDI/graphene and PFPDI-graphene. Next, testing their ability to operate in energy conversion schemes, the PFPDI-graphene was successfully employed as catalyst for the reduction of 4-nitrophenol to 4-aminophenol. Notably, the kinetics for the reduction were enhanced by visible light photoirradiation as compared to dark conditions as well as the presence of PFPDI-graphene, contrasting the case where only PFPDI, in the absence of graphene, was employed. Finally, recycling of the catalyst PFPDI-graphene was achieved and reutilization in successive reduction reactions of 4-nitrophenol was found to proceed with the same efficiency.

Abstract  The self-organizing structures formed by a water-soluble perylene diimide dye (PDI) have been studied by several experimental techniques as potential templates for the preparation of hybrid nanomaterials. The dye forms chromonic-nematic and hexagonal liquid crystals in water. The aggregates in liquid crystals consist of one-molecule-wide stacks. From the changes in the solution proton NMR chemical shifts with concentration, it appears that adjacent molecules are twisted. There is significant broadening of the aromatic resonances at higher concentrations, arising from nonmotionally averaged dipole-dipole coupling between adjacent aromatic hydrogens. This is attributed to slow overall rotation of the aggregates in solution, suggesting that they grow up to several tens of nanometers. Dye aggregates serve as templates for the formation of silica tubules (1-5 μm length, average diameter ≈300 nm), with aligned and very thin (1-2 nm) dye nanostripes embedded in the walls. The silica tubes precipitated from solution are formed by the cooperative interaction between PDI and silica species during the sol-gel reaction. Upon calcination, silica nanotubules with supermicroporous walls are obtained. In comparison with conventional surfactant systems, the use of π-π stacked chromonic aggregates brings new possibilities for the templated fabrication of pores with sizes below the mesoporous range. Materials could find applications in photovoltaics as well as in shape selective catalysis and adsorption.

Abstract  As the agency continues working on the final risk evaluation for PV29, we are interested in information from people that process PV29 for plastics and paint manufacturing to better understand exposures. During conference calls over the last week, Sun Chemical Corporation confirmed their intent to seek downstream processing information on PV29. Sun Chemical Corporation requested the types of information that could inform the risk evaluation and requested EPA provide some written questions. The questions are below. Compiling and submitting this data is entirely voluntary.

Abstract  A series of 4-amino-N-substituted-1,8-naphthalimide and 4-allylamino-N-substituted-1,8-naphthalimide derivatives were synthesized from intermediate 4-nitro-1,8-naphthalimide by imidation, reduction and allylation reactions. These compounds were characterized by thin layer chromatography (TLC), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), elemental analysis, H-1-nuclear magnetic resonance (1HNMR), C-13-NMR, liquid chromatography-mass spectroscopy, UV-Vis spectroscopy and fluorimetry. 1,8-Naphthalimide derivatives with amino and allylamino groups in the C-4 position exhibit fluorescent emission on irradiation. In addition, synthesized compounds had biological properties due to the presence of sulfonamide group (-SO2-N-) in their structure. The absorption maximum wavelength of synthesized dyes that are fluorescent is in the range of 427-439 nm while emitting in the range of 526-528.5 nm. The absorption spectra of synthesized dyes demonstrated that the type of substitutions in C-4 position and N-imide of naphthalimide ring had small effect on their colour. The photophysical characteristics of these dyes were assessed, and their Stokes shift values were determined in dimethylformamide solvent. The results demonstrated that Stokes shift values were between 3860 and 4469 cm(-1). Antibacterial and antifungal activities of the dyes were evaluated against gram positive and gram negative bacteria and Candida albicans fungi using cup plate, minimum inhibitory concentration and minimum bactericidal concentration methods. The results revealed that dye 10 had the most levels of antimicrobial activity against bacteria and fungi.

Abstract  This OECD Emission Scenario Document (ESD) is intended to provide information on the sources, use patterns, and potential release pathways of non-volatile chemicals used in textile dyes. The document focuses primarily on the application of dyes to fibers, yarns and fabrics by batch or continuous processes. The document presents standard approaches for estimating the environmental releases of and occupational exposures to non-volatile chemicals used in dye formulations.

Abstract  Most polymers employed in organic photovoltaic cells have pi-conjugated backbones Here we investigate the physical and optoelectionic properties of three nonconjugated polymers based on perylene diimides The optical properties. exciton diffusion length, band edge positions, conductivity, and carrier mobility of these polymers are described They are electron-conducting and highly photostable The film structure and optoelectronic properties vary with deposition conditions and annealing procedures One of the polymers has an unusually long exciton diffusion length of 22 nm. The free electron density resulting from n-type charged defects is similar to 3 x 10(15) cm(-3) in one polymer and is even lower in the others Simple bilayer solar cells are limited by their series resistance suggesting that these semiconductor films would benefit from doping

Abstract  Fluorescent monodisperse polystyrene microspheres were prepared by two-stage dispersion polymerization, which successfully covalently labeled microspheres with two dyes without disturbing the final particle size and size distribution. By varying the dye concentrations, microspheres show tuned colors with different fluorescent intensity under a single wavelength excitation. Fluorescence resonance energy transfer (FRET) between two labeled dyes was proved to contribute to the emission of the longer-wavelength dye at a shorter-wavelength excitation. There is no dye leakage for microspheres because of the covalent incorporation of dye molecules. The microsphere matrix provides good protection of dye molecules and blocks the influence of media outside on the fluorescence of microspheres. Single microsphere shows intense fluorescence due to a large number of encapsulated dye molecules. These uniform barcoding fluorescent microspheres have potential application in multiplexed bioanalysis. (c) 2007 Elsevier B.V. All rights reserved.

Abstract  A new class of polyelectrolyte-surfactant (PE-surf) composites having potential applications as thin film organic semiconductors is introduced. These materials are comprised of cationic asymmetrically substituted perylene diimides and oppositely charged poly(acrylate) polyanions. Thin films of the composite materials are prepared by mixing and drop casting aqueous solutions of the two precursors onto appropriate substrates. The resulting materials yield photovoltages of >140 mV for approximately equal to 0.6 W/cm(2) illumination intensities, when incorporated in p-n heterojunction devices. Solution-phase spectra obtained from the PE-surf complexes exhibit excimer-like emission and evidence for formation of weakly coupled aggregates in the ground state. Wide-angle X-ray scattering data show the composite films are locally amorphous, while small-angle X-ray data are consistent with a mixture of polymorphic structures that incorporate planar PE-surf bilayers of 3.9-nm repeat distances. Images obtained by conventional far-field light microscopy and multiphoton-excited fluorescence microscopy (MPEFM) indicate that the films are heterogeneous, incorporating submicrometer sized clusters dispersed among much thinner film regions that also incorporate dye. Polarization-dependent MPEFM studies prove the clusters are semiorganized, yielding order parameters (s and P(4)) of 0.09 and 0.01 for in-plane alignment of the chromophores, consistent with a relatively high degree of disorder.

Abstract  In this study, a solution-processed n-type photo-sensing organic thin film transistor was investigated using polymeric dielectric under different white light illuminations. N, N'-di (2-ethylhexyl)-3,4,9,10-perylene diimide and divinyl tetramethyl disiloxane-bis (benzo-cyclobutene) were used as a soluble active organic semiconductor and as a dielectric material, respectively. Stable amplification was observed in the visible region without gate bias by the device. The electrical characterization results showed that an n-type phototransistor with a saturated electron mobility of 0.6 x 10(-3) cm(2)/V.s and a threshold voltage of 1.8 V was obtained. The charge carrier density of the channel of the device exhibited photo-induced behaviors that strongly affected the electrical properties of the transistor. The photosensitivity and photoresponsivity values of the device were 63.82 and 24 mA/W, respectively. These findings indicate that perylene diimide is a promising material for use on organic based phototransistors. (C) 2014 Elsevier B.V. All rights reserved.

Abstract  Several new 1,8-naphthalimide dyad compounds connected with 1,3,4-oxadiazole at different substitution positions were synthesized, in which there are two compounds to be copolymerized with N-vinyl carbazole to form a single-layer electroluminescence (EL) device film, which consists of electron-transporting unit (oxadiazole), hole-transporting unit (PVK) and emitting unit. The photoemission and electroemission of these dyad compounds are near 540 nm, with a maximum luminance of 350 cd/m(2) and luminous efficiency of 3.02 lm/W at 14 V. (C) 1998 Elsevier Science S.A. All rights reserved.

Abstract  The reduction of the two 3,4,9,10-perylene diimide (PDI) derivatives in the mixture of hydrazine hydrate and N, N-dimethylformamide was investigated by the UV-vis absorption spectra, fluorescence spectra (FL) and electron spin resonance spectroscopy (ESR). The time dependence of the PDI content, as well as the structure of PDI aggregates were also investigated and discussed. Combining the electro-migration behavior of PDI- with the molecular self-assembly properties, the films of two PDI derivatives (PDI-32 and PDI-123) were successfully fabricated via anode electro-deposition (AED). The difference of aggregation state between the two PDI films was studied by UV-vis absorption spectra, XRD and SEM. Based on these, the formation mechanism of PDI films was also deduced.

Abstract  We report the interface properties of a perylene-diimide thin film between Au and n-Si substrate fabricated by the spin coating method. The relaxation time (tau) and interface trap density (D (it)) characteristics of the fabricated structure were obtained across various voltage ranges (0.0 V-300 mV) and various frequency ranges (1 kHz-1 MHz). We observed a peak in G (it)/omega versus log (f) plots from 0.0 V to 300 mV. This peak shows the presence of the interface state and its relaxation time. We observed a decrease in values at the same time as an increase in N (ss) values with the increasing applied voltage for the sample. The N (ss) and tau values found to be in the ranges 1.50 x 10(12) eV(-1) cm(-2)-2.83 x 10(12) eV(-1) cm(-2) and 2.83 x 10(-6) s-4.82 x 10(-7) s between 0.0 V and 0.3 V, respectively.