Abstract  Fluorene-containing N boolean AND N Pt(II) bisacetylide complexes were prepared, in which the fluorene moieties were connected to the Pt(II) center via acetylide bonds (-C C-). Different aryl groups were attached to the fluorene moiety, such as phenylacetylide (Pt-4), naphthalimide-4-acetylide (Pt-1) and in Pt-2, the fluorene moiety was changed to carbozale moiety. We found that with the fluorene linker between the arylacetylide and the Pt(II) center, the absorption of complexes in the visible range were intensified. All the complexes show room temperature (RT) phosphorescence. Furthermore, Pt-1 shows much longer triplet excited state lifetime (tau = 138.1 mu s) than the analogue Pt-3 (tau = 47.4 mu s). For Pt-2, with changing the fluorene moiety to carbazole moiety, the T-1 state lifetime becomes much shorter (tau = 23.0 mu s). Thus the one-atom (N vs. C) difference is crucial for the photophysical properties. The triplet excited state of Pt-1 was proved to be the intraligand excited state ((IL)-I-3) by nanosecond time-resolved transient absorption spectroscopy, spin density analysis and emission at 77 K. The complexes were used as triplet sensitizers for triplet-triplet annihilation (TTA) upconversion. Upconversion quantum yield (Phi(UC)) up to 24.3% was observed for Pt-1. Under the same conditions the model complex Pt-4 shows no upconversion. The overall upconversion efficiency (eta) of the new complexes are improved compared to the model complexes, such as Pt-2, Pt-3 and Pt-4. The improved upconversion efficiency was attributed to either the prolonged T-1 excited state lifetime or the intensified absorption in the visible range. Our study on the fluorene-containing N boolean AND N Pt(II) bisacetylide complexes will be useful for designing new phosphorescent Pt(II) complexes and for their applications.

Abstract  This paper reports the synthesis and electrochemical and optical properties of two molecular dyads (Dyad 1 and Dyad 2) consisting of a 2,7-bis(4-(diarylamino)styryl)carbazole two-photon-absorbing donor chromophore, connected by different linkers to a perylene diimide (PDI) acceptor. The photoinduced charge transfer in these compounds is characterised using transient absorption measurements. The use of the compounds for optical limiting is discussed; because of spectral overlap between the donor two-photon absorption band and the one-photon absorption band of the PDI radical anion, the dyads exhibit enhanced nonlinear absorption at wavelengths between 700 and 800 nm relative to that seen for the two-photon absorbing donor chromophore. The stronger nonlinear absorption observed for Dyad 1 vs. Dyad 2 is attributed to a higher yield of photo-generated radical ions and a longer lived charge-separated state, resulting from differences in the linker between the donor and acceptor.

Abstract  A new diamine with phthalic diimide moiety, i.e. N,N'-bis(4-amino-2,3,5,6-tetramethylphenyl)phthalene-1,4-dicarboxyimide was synthesized and applied for condensation with 4-(4,4,5,5,6,6,7,7,8,8,9,9,10, 10,11,11,11-heptadecafluoroundecyloxy)benzaldehyde and 4-octadecyloxybenzaldehyde, which resulted in two new azomethine-phthalic diimides (AZ-PDIs). Thermal, optical and electrochemical properties of AZ-PDIs were discussed in relation to their analogous containing instead of five-membered six-membered imide rings (AZ-NDIs) described in our previous work. The phase behavior of AZ-PDIs examined by differential scanning calorimetry (DSC) and polarized optical microscopy (POM) confirms their liquid crystalline properties in wide range of temperatures. AZ-PDIs do not show decomposition below 400 degrees C as was found based on thermogravimetric analyses (TGA). Optical properties of the prepared compounds were investigated by UV-vis and photoluminescence (PL) measurements. Azomethine-phthalic diimides emitted blue light with emission maximum (lambda(em)) at ca. 446-492 nm contrary to azomethine-naphthalene diimides which emitted green light and lambda(em) was at 536 and 540 nm. The obtained compounds are electrochemically active and undergo reversible reduction and oxidation as evidenced by differential pulse voltammetry (DPV). The azomethine-phthalic diimides exhibited low electrochemical band gap ca. 1.68 eV being promising for optoelectronic applications. (c) 2013 Elsevier B.V. All rights reserved.

Abstract  Treatment of sandwich-type mixed (phthalocyaninato)( porphyrinato) metal complex [HEu(III){Pc(alpha-3-OC(5)H(11))(4)}{TriBPP( NH(2))}] (3) [Pc(alpha-3-OC(5)H(11))(4)=1,8,15,22-tetrakis(3-Pentyloxy)-phthalocyaninate, TriBPP(NH(2))=5,10,15-tris(4-tert-butylphenyl)-20-(4-aminophenyl)porphyrinate] with N-n-butyl-1,6,7,12-tetra(4-rert-butylphenoxyl)perylene-3,4-dicarboxylate anhydride-9,10-dicarboxylate imide (2) in the presence of imidazole in toluene afforded the novel perylene diimide-appended mixed (phthalocyaninato)(porphyrinato) europium(III) double-decker complex (5). Porphyrin-PDI dyad 4 was also obtained by similar method. The electronic absorption spectroscopic and electrochemical properties of PDI-appended double-decker sand the model compounds 2, 3, and 4 were studied, the results indicated that there was no considerable ground-state interaction between the double-decker unit and the PDI unit in 5. The fluorescence measurements revealed that the emission of PDI unit was effectively quenched by the double-decker unit, suggesting remarkable intramolecular interaction in 5 under excited state. (C) 2011 Elsevier Ltd. All rights reserved.

Abstract  Phenol substituted 1,8-naphthalimide derivatives acting as a donor and an iridium(III) complex which emits orange light acting as an acceptor were synthesized to fabricate a novel white-light-emitting two-component gel. The intermolecular energy transfer between the two components plays a crucial role in providing the tuneable emission in the mixed gels. The emission of white light can be obtained by carefully tuning the ratio of the two components. These gels are ideal constituents for the design of supramolecular light-harvesting materials, which afford a novel approach to displaying information in soft materials with tuneable optical properties. Furthermore, the two-component gel can respond to cysteine with an obvious change in luminescence that is visible to the naked eye.

Abstract  Di-(N-butanoic acid-1,8-naphthalimide)-piperazine dithienylethene was covalently linked to a cysteamine monolayer associated with a Au surface to yield a photoisomerizable monolayer composed of the open or closed dithienylcyclopentene isomers (3a or 3b), respectively. Electrochemical and XPS analyses reveal that the association of metal ions to the monolayer is controlled by its photoisomerization state. We find that Cu(2+) ions reveal a high affinity for the open (3a) monolayer state, K(a) = 4.6 × 10(5) M(-1), whereas the closed monolayer state (3b) exhibits a substantially lower binding affinity for Cu(2+), K(a) = 4.1 × 10(4) M(-1). Similarly, Ag(+) ions bind strongly to the 3a monolayer state but lack binding affinity for the 3b state. The reversible photoinduced binding and dissociation of the metal ions (Cu(2+) or Ag(+)) with respect to the photoisomerizable monolayer are demonstrated, and the systems may be used for the photochemically controlled uptake and release of polluting ions. Furthermore, we demonstrate that the photoinduced reversible binding and dissociation of the metal ions to and from the photoisomerizable electrode control the wettability properties of the surface.

Abstract  In this paper, one methacrylate monomer contaming naphthalimide as electron acceptor and aromatic hydrazone as electron donor was designed and synthesized. Its copolymer with styrene has been incorporated into sandwiched memory devices which show dynamic random access memory, characteristics with highest ON/OFF current ratio up to 10(6) and a long retention time. Moreover, it was observed that switch threshold voltage of the device varied almost linearly with functional moiety content in the copolymer. The photoluminescence spectra and X-ray diffraction of the copolymer's film were investigated and the results showed that the functional moieties in the pendant chains occurred as pi-pi stacking and the distance between each other became closer as the functional moieties content in the copolymer increased The mechanisms associated with dram characteristics were elucidated from molecular simulation results that the slight electron density transition from the HOMO to LUMO surfaces would easily revert to original state once the external electric field was removed.

Abstract  Combined electronic structure and quantum dynamical calculations are employed to investigate charge separation in a novel class of covalently bound bisthiophene-perylene diimide type donor-acceptor (DA) co-oligomer aggregates. In an earlier spectroscopic study of this DA system in a smectic liquid crystalline (LC) film, efficient and ultrafast (subpicosecond) initial charge separation was found to be followed by rapid recombination. By comparison, the same DA system in solution exhibits ultrafast resonant energy transfer followed by slower (picosecond scale) charge separation. The present first-principles study explains these contrasting observations, highlighting the role of an efficient intermolecular charge-transfer pathway that results from the molecular packing in the LC phase. Despite the efficiency of this primary charge-transfer step, long-range charge separation is impeded by a comparatively high Coulomb barrier in conjunction with small electron- and hole-transfer integrals. Quantum dynamical calculations are carried out for a fragment-based model Hamiltonian, parametrized by ab initio second-order Algebraic Diagrammatic Construction (ADC(2)) and Time-Dependent Density Functional Theory (TDDFT) electronic structure calculations. Simulations of coherent vibronic quantum dynamics for up to 156 electronic states and 48 modes are performed using the Multi-Layer Multi-Configuration Time-Dependent Hartree (ML-MCTDH) method. Excellent agreement with experimentally determined charge separation time scales is obtained, and the spatially coherent nature of the dynamics is analyzed.

Abstract  Due to their high electron affinities, chemical and thermal stabilities, π-conjugated molecules with imide/amide frameworks have received considerable attentions as promising candidates for high-performance optoelectronic materials, particularly for organic semiconductors with high carrier mobilities. The purpose of this Research News is to give an overview of recent advances in development of high performance imide/amide based organic semiconductors for field-effect transistors. It covers naphthalene diimide-, perylene diimide- and amide-based conjugated molecules and polymers for organic semiconductors.

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  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  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  The molecular packing of a new class of perylene diimide-based acceptor-donor (A-D) co-oligomers has been investigated by combining electron diffraction and X-ray scattering methods for AD dyads and an ADA triad structure. The AD and ADA compounds form highly ordered lamellar mesophases with well-defined donor and acceptor domains. To determine the structure of the co-oligomers, highly oriented films with different orientations were prepared. Both flat-on and edge-on orientations of the lamellae were obtained by using two different alignment methods. High temperature rubbing leads to edge-on oriented lamellae with the long molecular axis of the co-oligomer oriented almost parallel to the rubbing direction. Instead, on oriented substrates of poly(tetrafluoroethylene) (PTFE), flat-on lying lamellae with the pi-stacking direction oriented parallel to the PTFE chains are obtained. The structural data gathered by low dose selected area electron diffraction and high resolution transmission electron microscopy are used to establish a structural model of an AD dyad. Driven by the strong pi-stacking of the PDI core, both AD and ADA co-oligomers form two similar self-assembled lamellar structures with an original zipper-like organization of the PDI blocks.

Abstract  Perovskite hybrid solar cells (pero-HSCs) were demonstrated to be among the most promising candidates within the emerging photovoltaic materials with respect to their power conversion efficiency (PCE) and inexpensive fabrication. Further PCE enhancement mainly relies on minimizing the interface losses via interface engineering and the quality of the perovskite film. Here, we demonstrate that the PCEs of pero-HSCs are significantly increased to 14.0% by incorporation of a solution-processed perylene-diimide (PDINO) as cathode interface layer between the [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) layer and the top Ag electrode. Notably, for PDINO-based devices, prominent PCEs over 13% are achieved within a wide range of the PDINO thicknesses (5-24 nm). Without the PDINO layer, the best PCE of the reference PCBM/Ag device was only 10.0%. The PCBM/PDINO/Ag devices also outperformed the PCBM/ZnO/Ag devices (11.3%) with the well-established zinc oxide (ZnO) cathode interface layer. This enhanced performance is due to the formation of a highly qualitative contact between PDINO and the top Ag electrode, leading to reduced series resistance (R-s) and enhanced shunt resistance (R-sh) values. This study opens the door for the integration of a new class of easily-accessible, solution-processed high-performance interfacial materials for pero-HSCs.

Abstract  A triple bond-linked perylene diimide (PDI) conjugated polymer, poly{[N,N'-dioctylperylene-3,4,9,10-bis(dicarboximide)-1,7(6)-diyll-alt-[(2,5-bis(2-ethylhexyl)-1,4- phenylene)bis(ethyn-2,1-diyl]} (PDIC8-EB), was examined as an electron-accepting component in all-polymer solar cells. As an electron-donating component, poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyllthieno[3,4-b]-thiophenediyl] (PTB7) and poly[4,8-bis(5-(2-ethylhexyp thiophen-2-yl)benzo[1,2-b:4,5-b'] dithiophene-alt-3-fluorothieno [3,4-b]thiophene-2-carboxylate] (PTB7-Th) were introduced in order to investigate the feasibility of PDIC8-EB because of their similarity. Results showed that the power conversion efficiency (PCE) was higher for the PTB7-Th:PDIC8-EB solar cells (PCE = 3.58%) than the PTB7:PDIC8-EB solar cells (PCE = 2.81%). The better performance of the PTB7-Th:PDIC8-EB solar cells has been attributed to the formation of a well-defined nanodomain morphology in the PTB7Th:PDIC8-EB bulk heterojunction layer, as measured with transmission electron microscopy (TEM), atomic force microscopy (AFM), and synchrotron radiation grazing incidence X-ray diffraction (GIXD).

Abstract  A nonfullerene electron acceptor (IEIC) based on indaceno[1,2-b:5,6-b']dithiophene and 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile was designed and synthesized. IEIC exhibited good thermal stability, strong absorption in the 500-750 nm region with an extinction coefficient of 1.1 x 10(5) M-1 cm(-1) at 672 nm, deep LUMO energy level (-3.82 eV) close to those of fullerenes, and a relatively high electron mobility of 2.1 x 10(-4) cm(2) V-1 s(-1). Fullerene-free polymer solar cells (PSCs) based on the blends of the IEIC acceptor and a low-bandgap polymer donor PTB7-TH, using a perylene diimide derivative as a cathode interlayer, showed power conversion efficiencies (PCEs) of up to 6.31%, which is among the best PCEs reported for fullerene-free PSCs.