Abstract  Switchable supramolecular self-assemblies on the basis of interaction between melamine group containing photochromic diarylethene unit (DTE) and naphthalimide derivate (1) were designed and fabricated. 1 can gelate several aprotic solvents with different morphologies. The gel turned into partial gel in ethyl acetate with the addition of DTE as a guest molecule. Both the absorption and fluorescence spectra of the assembly can be reversibly switched by alternating UV/visible light irradiation. Meanwhile, the morphology of the coassembly of 1(2)·DTE changed to film from original pieces of gel 1 in ethyl acetate. When 1(2)·DTE was irradiated by UV light, the film morphology was converted into aggregated flakes. Moreover, the surface wettability of the complex can also be switched by light irradiation. The photochromic diarylethene unit is able to modulate the fluorescence and morphology of the assembled system only by virtue of light irradiation. Therefore, these results provide further insights into fluorescence and morphology controlling, especially application in upscale smart responsive materials.

Abstract  Two new perylene diimide derivatives N,N'-bis(5-tridecyl-1,3,4-thiadiazol-2-yl) perylene-3,4,9,10-tetracarboxylic 3,4:9,10-diimide (PDI-T1) and N, N'-bis[5-(1-hexyl) nonyl-1,3,4-thiadiazol-2-yl] perylene-3,4,9,10-tetracarboxylic 3,4:9,10-diimide (PDI-T2), achieved by functionalizing the basic perylene molecular core at imide nitrogen with 1,3,4-thiadiazole rings, have been synthesized. Both these compounds make possible the fabrication of n-type organic thin-film transistors able to work in air, even when bare SiO2 surfaces are utilized as gate dielectric. As active channels of transistors in the bottom-contact bottom-gate configuration, PDI-T1 evaporated films exhibited a maximum mobility of 0.016 cm(2)/V s in vacuum. For evaporated PDI-T2 films, instead, mobility values were found to be more than one order of magnitude lower, because of their reduced degree of crystalline order. However, PDI-T2 films can be also deposited by solution techniques and field-effect transistors were fabricated by spin-coating, displaying mobility values ranging between 10(-6) and 10(-5) cm(2)/V s. Similar to what previously found for other perylene diimide derivatives, our experimental work also demonstrates that the electrical response of both PDI-T1 and PDI-T2 transistors under ambient conditions can be improved by increasing the level of hydrophobicity of the dielectric surface. (c) 2012 Elsevier B.V. All rights reserved.

Abstract  A novel heteroleptic ruthenium(II) complex D1 with a pni (3-(2'-pyridyl)-1,8-naphthalimide) derivative as a heteroleptic donor was designed and theoretical studies were performed of the molar absorptivity of D1 compared to that of the standard N749 dye and [Ru(dcbpy)(2)(ppy)] (dcbpy 4,4'-dicarboxy-2,2'-bipyridine, ppy = 2-phenylpyridine). Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were used to gain an insight into the factors responsible for the photovoltaic properties of the dye sensitizer. The results showed that the absorption spectrum of the D1 dye with the pni derivative was red-shifted compared to N749 and [Ru(dcbpy)(2)(ppy)], particularly, in the region above 600 nm. The red-shift was attributed to the heteroleptic electron-donating ligands of the D1 dye. According to the molecular orbital analysis, the LUMO of the D1 dye mainly localized on tctpy (4,4',4 ''-tricarboxy-2-2':6'.2 ''-terpyridine) moiety. HOMOs of the N749 were localized on the NCS moiety. However, HOMO and HOMO-2 of D1 were localized on the Ru-NCS moiety and the Ru-pni moiety, respectively. Owing to the additional HOMO-2, the D1 dye had a broad absorption spectrum and high photovoltaic efficiency compared to N749.

Abstract  4-Alkylamino-N-alkyl-1,8-naphthalimides were prepared from 4-chloro-1,8-naphthalic anhydride and from 4-amino-1,8-naphthalimide. It was found that the amino nitrogen of 4-amino-N-alkyl-1,8-naphthalimides is nucleophilic enough to participate in nucleophilic displacement reactions without the need for added base, despite being a vinylogous amide. Bromination of 4-alkylamino-N-alkyl-1,8-naphthalimides using molecular bromine was found to occur in the absence of a Lewis acid catalyst, and to be regiospecific, yielding only the 3-bromo isomer. Extended reaction times and the use of excess bromine result in dealkylation of the 4-alkylamino substituent, but no polybromination of the naphthalimide ring system. (C) 1999 Elsevier Science Ltd. All rights reserved.

Abstract  Microporous polyethylene (PE) films with good mechanical properties have been produced by high-speed extrusion from the melt followed by annealing, uniaxial stretching and thermal fixation. The films have pores of 0.15-0.45 mum size and relief on the scale of 1-2 mum. Coloration of the films with fluorescent dyes, 3-aminobenzanthrone and derivatives of 1,8-naphthalimide, was performed at the room temperature. The quantity of adsorbed dye depends upon the spin draw ratio of PE membranes and has an influence upon their color shade. The color effect is not observed in the case of only extruded or annealed PE films treated in the same way. The enhanced adhesion of the dyes on porous films is related to their high surface area. Specifically, the interactions between dye and polymer at pore walls provide color stability of the microporous films. The effect of relevant properties of both PE membranes (pores relief and lamellar thickness) and dye molecules (aspect ratio and cohesion) is discussed.

Abstract  The copolymerization of 1,8-naththalimide derivatives (as fluorophore) with acrylonitrile has been investigated. The photophysical characteristics of monomeric and polymeric fluorophores in N,N-dimethylformamide solution have been determined and discussed. During copolymerization, no changes in the chromophoric systems of the fluorophore occur. The influence of the studied monomeric 1,8-naphthalimide fluorophores upon the structurally bleached polyacrylonitrile has been determined. Infrared adsorption characteristics of the polymerizable 4-alkoxy-and 4-allyloxy-N-substituted 1,8-naphthalimides have been measured and discussed. The effect of the substituents upon the vibration frequencies of the carbonyl and allylic groups has been established.

Abstract  A series of novel monoazo disperse dyes based on N-ester-1,8-naphthalimides were synthesized using 4-amino-N-methylglycinate-1,8-naph-thalimide and 4-amino-N-ethylglycinate-1,8-naphthalimide, as diazo components, with various couplers. The spectrophotometric properties of the dyes were examined in different solvents and their solvatochromism effects were investigated. The dyes displayed lambda(max) of between 515 and 563 nm and the molar extinction coefficient of the dyes varied from 25,863 to 49,080 l mol(-1) cm(-1). Most of the dyes showed acceptable build up properties on polyester fibres under high temperature conditions and displayed moderate light fastness and very good wash and dry heat fastness on polyester fibres. The results indicated that the presence of an ester group within the dye molecule provided alkali-clearable potential. (c) 2007 Elsevier Ltd. All rights reserved.

Abstract  The solubility of naphthalimide-based monoazo dyes containing N-ethyl and N-ethanoic acid groups was investigated in the presence of a conventional monomeric counterpart (DTAB) and two cationic gemini surfactants (12-4-12 or 14-4-14) individually. The effective parameters on dye solubility such as temperature, time and concentration of surfactants were investigated by UV-Visible spectrophotometry. The results demonstrate that the solubility of both dyes was considerably increased at concentrations above the surfactant CMC. The wavelength for the maximum absorbance of dyes in the aqueous solution shifts toward longer wavelengths with changes in the concentration of the cationic surfactants. A kinetic study of solubilization of dyes in cationic surfactants solution showed that the rate of solubilization follows the pseudo-first-order reactions. Rates of solubilization were in the range of 0.5 x 10(-3) to 6.8 x 10(-3) min(-1) for both dyes. The disperse dye containing a carboxylic acid group (dye 2) has a higher solubility rate than the dye containing an alkyl group (dye 1). The type of surfactant has a very low effect on adsorption of dye 1 onto the polyester fibers, whereas changing the surfactant type from DTAB to 12-4-12 or 14-4-14 causes adsorption of dye 2 on polyester to decrease.

Abstract  This paper reports the first fluorescent sensor for medium-chain fatty acids in water. The hybrid sensing material (S2) was prepared by the reaction of a rationally designed "recognition center", N-butyl-4-piperazin-1,8-naphthalimide, with a 3-glycidoxypropyl group which is pre-grafted on the interior of a mesoporous solid (MCM-41). The organo-functionalization of the mesoporous solid (MCM-41) was confirmed by FT-IR, Si-29 MAS NMR and elemental analysis. The results of XRD, N-2 physical adsorption-desorption, SEM and TEM studies proved that the organized structure of the nanoscopic porous solid is preserved after the reactions. The fatty acid-selective signaling behavior of S2 was investigated in water at pH = 5.80/7.16/8.00. This material displays much stronger fluorescence enhancement with C-8-C-12 fatty acids than with the shorter and longer chains in aqueous media, both in the absence and in the presence of aromatic acids.

Abstract  Coloured polymers of acrlylonitrile with 4 polymerizable fluorescent dyes (1,8-naphthalimide derivatives) have been obtained. The influence of the dye on thermostability and the molecular weights of the coloured polymers have been determined. It was established that between 85 and 95% of the dye was incorporated into the polymer molecule, providing resistance to wet treatments and solvents. (C) 1997 Elsevier Science Ltd.

Abstract  A new thiophene-fused naphthalimide building block, 9-(2-decyltetradecyl)-8H-dithieno-[3',2':3,4; 2 '',3 '':5,6]benzo[1,2-f]isoindole-8,10(9H)-dione (4), was synthesized and three novel conjugated copolymers P1-P3 based on this building block and electron-rich units such as 4,4'-didodecyl-2,2'-bithiophene (for P1), benzo[1,2-b:4,5-b']dithiophene (for P2) and 3,6-didodecylthieno[3,2-b] thiophene (for P3) were prepared by Stille coupling polymerization. The optical, electrochemical and thermal properties of polymers P1-P3 were studied and their applications in organic field effect transistors (OFETs) were also investigated. These new polymers have good solubility in common organic solvents and exhibit good thermal stability. Polymers P1 and P3 entered nematic liquid crystalline phases above 213 and 313 degrees C, respectively. The average field-effect hole mobilities were evaluated to be 0.15, 3 x 10(-3) and 0.05 cm(2) V-1 s(-1) for P1, P2 and P3, respectively, under ambient conditions, with a high on/off ratios of 10(5)-10(7). All the OFETs based on these polymers showed good environmental stability when stored in air.

Abstract  Fluorination of alkyl groups is a known strategy for hindering miscibility, thus promoting phase separation, when blends are prepared with a hydrocarbon compound. A new perylene bis(dicarboximide) derivative functionalized with branched N-perfluoroalkyl moieties (BPF-PDI) has been synthesized as electron acceptor to be potentially used in conjunction with the electron donor hexakis(dodecyl) hexabenzocoronene (HBC-C(12)) in bulk heterojunction solar cells. Aiming at controlling self-assembly between the two components at the supramolecular level, stoichiometric blends in CHCl(3) have been prepared either by spin-or drop-casting onto silicon surfaces, and further subjected to solvent vapour annealing (SVA) treatment in a CHCl(3)-saturated atmosphere. Spectroscopic investigation in solution shows the formation of supramolecular BPF-PDI-HBC-C(12) dimers, with an association constant K(ass) = (2.1 +/- 0.3) x 10(4) M(-1), pointing to a strong and unexpected affinity between the two species within the mixture. Characterization through optical and atomic force microscopies of the deposited samples revealed that the self-assembly behaviour of the blends on SiO(x) is remarkably different from mono-component films, thus confirming the absence of a macroscopic phase-separation between the two components featuring isolated domains of the neat acceptor or donor compound. In addition, X-ray studies provided evidence for the existence of a local-scale phase separation. These findings are of importance for organic photovoltaics, since they offer a new strategy to control the phase separation at different scales in electron acceptor-donor blends.

Abstract  The structural and optical properties of Langmuir-Blodgett (LB) films of two perylene diimide derivates, N,N'-Bis(propyl)-3,4,9,10-perylenebis(dicarboximide) and N,N'-Bis(neopentyl)-3,4,9,10-perylenebis(dicarboximide), are reported. The surface pressure-area (pi-A) isotherms have evidenced how the lateral chain substituents control the strength of the intermolecular interaction. Nevertheless, a head-on tilted molecular orientation on the water subphase was found for both compounds. This molecular orientation is preserved when the monolayers are transferred onto substrates. Molecular orientation in the films was extracted from comparative analysis of transmission and reflection-absorption infrared spectroscopy (RAIRS) data. Film structure has been studied by means of atomic force microscopy (AFM). The observed different emission profiles have been correlated with the ability of the derivatives to get coupled. (C) 2003 Elsevier B.V. All rights reserved.

Abstract  Three conjugated copolymers based on cyclopentadithiophene (CPDT) units, namely, poly{4,4-bis(2-ethylhexyl)cyclopenta[2,1-b:3,4-b']dithiophene-2,6-diyl-alt-2,1,3-benzothiadiazole-4,7-diyl} (P1), Poly{4,4-bis(2-ethylhexyl)cyclopeanta[2,1-b:3,4-b']dithiophene-2,6-diyl-alt-2,1,3-benzoselenadiazole-4,7-diyl} (P2) and Poly{4,4-bis(2-ethylhexyl)cyclopenta[2,1-b:3,4-b']dithiophene-2,6-diyl-alt-N,N'-bis(2-ethylhexyl)-3,4,9,10-perylene diimide-1,7-diyl} (P3) have been synthesized via Stille coupling reaction. The polymers were characterized by H-1 NMR spectroscopy, gel permeation chromatography (GPC), UV-vis absorption spectroscopy, and cyclic voltammetry. These new polymers exhibit broad and strong absorption between 500 and 800 nm. The highest occupied molecular orbital energy levels of polymers vary between -4.98 and -5.27 eV and the lowest unoccupied molecular orbital energy levels range from -3.43 to -3.70 eV. By employing P1 and P2 as electron donors (D) and P3 as electron acceptor (A), all-polymer solar cells with bulk heterojunction structure have been fabricated. Preliminary results indicate that these devices show higher open circuit voltage (V (OC) ) in comparison with the traditional polymer/fullerene systems of P1 and P2 blended with the acceptor (6,6)-phenyl C-61-butyric acid methyl ester (PCBM).

Abstract  Three near-infrared (NIR) absorbing unsymmetrical perylene diimide D A D type dyes containing 6-undecanoxy as donor group were utilized in dye-sensitized nanocrystalline TiO(2) solar cells. Structure of the acceptor side of the molecules were improved by adding 4-[2-methyl-5-(cyanoacrylic acid)-3-thienyl]-phenyl (V), 3-carboxy-2-pyridil (VI) and 3-carboxy-2-pyrazyl (VII) moieties attached to one of the N-side of the dye. The relationship between the molecular structure of the acceptor sites of the dyes and the photovoltaic performances were discussed. Electrochemical measurements indicated that band gaps of the dyes were energetically favorable for electron injection from the excited state of the dyes to the conduction band of TiO(2) nanoparticles. However, three dyes gave lower conversion efficiency on DSSC applications. Strong electron-withdrawing nature of perylene core might not permit to transfer the photo-generated electrons to the carboxyl groups anchoring to TiO(2) surface, and then solar-to-electricity conversion efficiencies of the dyes were reduced. (C) 2011 Elsevier Ltd. All rights reserved.

Abstract  Novel, symmetric and unsymmetric perylene diimide dyes with pyrene or indole units in the bay positions of the perylene ring were synthesized and characterized using FT-IR, (1)H and (13)C NMR, MS, UV-Vis spectra and cyclic voltammetry. The lambda(max) different solvents were in the range 526-585 nm and emission wavelengths of the dyes exhibited positive solvatochromism with increasing solvent polarity. Long wavelength emissions >750 nm of dyes with pyrene units displayed charge-separated state of perylene-pyrene system. Dyes with pyrene or indole units showed greater photostability in toluene than dyes which did not contain these bulky substituents. Incorporating electron-donating indole substituents lowered the band gap energies and, therefore, the HOMO energy levels were increased. The energy density and shape of the molecular orbitals were calculated theoretically. (C) 2009 Elsevier Ltd. All rights reserved.

Abstract  Nine compounds having electron-accepting 1,8-naphthalimide and electron-donating carbazole moieties were synthesized employing palladium-catalyzed C-N and C-C coupling reactions and characterized by the thermal methods, absorption and emission spectrometry, electrochemical and photoelectrical tools. The synthesized compounds possess high thermal stability with the 5% weight loss temperatures being in the range of 351-476 degrees C. Most of the synthesized compounds are capable of glass formation with glass transition temperatures ranging from 30 to 87 degrees C. The cyclic voltammetry measurements showed that the solid state ionization potentials values of the carbazole and 1,8-naphthalimide derivatives range from 5.46 eV to 5.76 eV and the electron affinities values range from -3.04 eV to -2.92 eV. Dilute solutions of the 3- and 3,6-naphthalimide-substituted derivatives of carbazole in polar solvents were found to emit in the green region with quantum yields ranging from 0.66 to 0.83, while in the solid state fluorescence quantum yields were found to be in the range of 0.01-0.45. ((E)-9-(((N-(2-ethylhexyl)-1,8-naphthalimide)-4-yl)ethenyl)-9H-carbazole) exhibited efficient fluorescence in the solid state with quantum yield as high as 0.45. The effects of the linking topology of the chromophores and of the incorporated alkyl substituents on the thermal, optical, and photoelectrical properties of the synthesized donor-acceptor compounds are analyzed. The impact of the ground state intramolecular twisting of the carbazole and naphthalimide moieties induced by the substituents resulting in significant variation in the rates of radiative and nonradiative excitation deactivation is revealed. (C) 2014 Elsevier Ltd. All rights reserved.

Abstract  Naphthalimide-substituted derivatives of fluorene were synthesized by Suzuki Miyaura coupling reactions. Most of the synthesized materials were found to constitute glasses with glass transition temperatures ranging from 30 to 76 degrees C as characterized by differential scanning calorimetry. Their initial weight loss temperatures range from 315 to 466 degrees C. Dilute solutions of the naphthalimide-substituted derivatives of fluorene in nonpolar solvents were found to emit in the blue region with high quantum yield ranging from 0.47 to 0.69, while in the solid state fluorescence quantum yields were found to be in the range of 0.06-0.25. Fluorenes possessing two naphthalimide moieties exhibited higher values of the fluorescence quantum yield due to enhanced oscillator strength of the transition. The derivatives of fluorene containing naphthalimide moieties exhibited pronounced positive solvatochromic behaviour in polar solvents indicating on charge-transfer character of the lowest excited states. Fluorescence red shift in dimethylsulfoxide is found of 94 nm, while the fluorescence quantum yield is increasing with polarity from 0.47 in cyclohexane to 0.84 in dimethylsulfoxide. Such untypical enhancement of fluorescence quantum yield is accounted to reduced intersystem crossing in polar solvents, which is proved by almost 10 fold increase in the values of nonradiative decay rate for compounds dissolved in polar solvents. Time-of-flight electron drift mobilities of the layer of 2,7-di((N-octyl-1,8-naphthalimide)-4-yl)-9,9-dioctyl-9H-fluorene in air at 25 degrees C appproach 1.2 x 10(-3) cm(2) V-1 s(-1) at an eletric field of 6.4 x 10(5) Vcm(-1). (C) 2013 Elsevier Ltd. All rights reserved.

Abstract  We report the control of molecular orientation in solid films through self-organization and inducedorientation processes. We synthesized water-soluble cationic 3,4,9,10-perylene diimide (1) and studied its self-organization in aqueous solution. By UV-vis spectroscopy, H-aggregates of 1 were observed forming in solutions with concentrations as low as 10(-7) M. At concentrations above approximately 0.1 M (7% w/w), these solutions were observed with polarized microscopy to form a chromonic N phase (a nematic lyotropic liquid crystalline phase) at room temperature. Upon induced alignment (by shearing) of the chromonic N phase on a glass substrate and removal of solvent, anisotropic solid films of the dichroic dye were produced. These films have dichroic ratio values that routinely exceed 25 and in some cases 30, making them excellent polarizers over the blue and green region. By use of a combination of polarized UV-vis and FT-IR spectroscopies, the orientation of the average molecular plane in these films was determined to be perpendicular to both the shearing direction and the substrate plane. Small-angle X-ray diffraction studies indicate that the molecules in the solid film possess a high degree of order.

Abstract  Abstract: A novel application of ethylene-norbornene cyclic olefin copolymers (COC) as gate dielectric layers in organic field-effect transistors (OFETs) that require thermal annealing as a strategy for improving the OFET performance and stability is reported. The thermally-treated N,N'-ditridecyl perylene diimide (PTCDI-C13)-based n-type FETs using a COC/SiO(2) gate dielectric show remarkably enhanced atmospheric performance and stability. The COC gate dielectric layer displays a hydrophobic surface (water contact angle = 95 degrees +/- 1 degrees) and high thermal stability (glass transition temperature = 181 degrees C) without producing crosslinking. After thermal annealing, the crystallinity improves and the grain size of PTCDI-C13 domains grown on the COC/SiO(2) gate dielectric increases significantly. The resulting n-type FETs exhibit high atmospheric field-effect mobilities, up to 0.90 cm(2) V(-1) s(-1) in the 20 V saturation regime and long-term stability with respect to H(2)O/O(2) degradation, hysteresis, or sweep-stress over 110 days. By integrating the n-type FETs with p-type pentacene-based FETs in a single device, high performance organic complementary inverters that exhibit high gain (exceeding 45 in ambient air) are realized. ds: Materials Science cument Delivery No.: 648KG

Abstract  The synthesis of two unprecedented series of dissymmetric molecular tweezers, with usnic acid, phenanthrene, or substituted naphthalimide arms as pincers, is described. Their association ability with the 2,4,7-trinitrofluorenone guest molecule has been quantified through NMR experiments in CD2Cl2 solution. Density Functional Theory calculations, including dispersion terms, have been carried out and rationalize both the conformational and the complexation mode behaviors of these new tweezers. With a naphthalimide and an usnic acid arms, the U-tweezer series indeed appears to behave as molecular tweezers. Conversely, in the P-tweezer series, involving a naphthalimide and a phenanthrene arm, the selected theoretical approach indicates that external complexes are more stabilized than the internal tweezed structures, corroborating experimental evidence of qualitatively different behaviors of the two series of tweezers.

Abstract  Fluorescence polarization (FP)-based signal is a self-referencing fluorescence signal, and it is less dependent on dye concentration and environmental interferences, which makes FP measurement an attractive alternative sensing technology to fluorescence intensity-based detection. However, most of the fluorescence polarization probes were constructed by introducing fluorescein, rhodamine, and cyanine dyes, which have relatively shorter excited-state lifetimes compared with BODIPY and naphthalimide dyes. Herein, a first naphthalimide based fluorescence polarization probe (BIO) was designed and synthesized for selective and direct detection of cancer cells. The relatively longer excited-state lifetimes and high photostability of naphthalimide makes BIO more sensitive and accuracy in quantitative determination of HeLa cells in homogeneous solution without cell lysis and further separation steps. The detection limit of BIO for HeLa cells was about 85 cells mL(-1), the linear range was from 2.5 × 10(2) cells mL(-1) to 1 × 10(6) cells mL(-1) and the response time is no more than 25 min. Moreover, due to the relatively high photostability of naphthalimide, BIO was particularly suitable for live cell imaging under continuous irradiation with confocal microscopy, and the specific interaction of BIO with CD44-overexpressing cell lines was clearly visualized. Importantly, this BIO based sensing platform offers a direct and real-time tool for cancer cell diagnosis when complemented with the use of naphthalimide-based fluorescence polarization probe.

Abstract  A novel folate fluorescent nanoconjugate was synthesized and used for detection of cancer cells overexpressing the folate receptor (FR). The folate conjugate (PCMS-NA-FA) was synthesized by conjugating folic acid (FA) and 4-ethylnyl-N-ethyl-1, 8-naphthalimide (NA) to the polychloromethylstyrene (PCMS) functionalized with azido group (PCMS-N₃) through click reaction. The obtained conjugate had clear structure and could form PCMS-NA-FA nanoparticles with particle size around 86 nm in aqueous solution. Ability of PCMS-NA-FA targeting to cancerous cells was investigated by comparing the uptake of the nanoparticles by human adenocarcinoma HeLa cells and by non-FR expressing human lung carcinoma A549 cells. Specificity of the PCMS-NA-FA nanoparticles targeting on FRs was verified with cellular uptake inhibition assay, in which HeLa cells were incubated with both nanoconjugate and free FA. In addition, the specificity was also confirmed by the collocation of the immunofluorescence staining of anti-FR and the cellular uptake of the PCMS-NA-FA nanoparticles. Furthermore, the organ distribution of this folate nanoconjugate was studied on HeLa cell-bearing mice via frozen slicing, and the results showed that the folate nanoparticles were preferentially accumulated in the tumor site rather than other tissues, indicating the desired specificity for tumor targeting and imaging. All these findings suggested that this practical synthetic strategy can potentially facilitate the preparation of multifunctional imaging probe in biology and diagnosis of disease.

Abstract  Three 1,8-naphthalimide based small molecules (NI-TAT-NI-C8, NI-TAT-NI-C12, and NI-TAT-NI-C16) have been synthesized and used as acceptor materials for wide band gap polymer solar cells. The side chains of the acceptor molecules have a significant influence on the molecular packing, morphology and photovoltaic performance. The octyl and 2-hexyldecyl substituted small molecular acceptors (NI-TAT-NI-C8 and NI-TAT-NI-C16)are prone to form J-aggregates as films; whereas dodecyl substituted one (NI-TAT-NI-C12) forms H-aggregates. Polymer solar cells with NI-TAT-NI-C12 as the acceptor showed much higher power conversion efficiency than that with NI-TAT-NI-C8 or NI-TAT-NI-C16 as the acceptor. Our results have demonstrated that the molecular packing as well as the photovoltaic performance could be modulated by varying the side chains of acceptor molecules. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  Four novel dyad monomers containing two copolymerizable groups have been synthesized. They were copolymerized with N-vinyl carbazole and would be used as electroluminescent materials, in which there are three functional segments: 1,8-naphthalimide as emitter, oxadiazole as electron-transporting unit and carbazole as hole-transporting segments. The effective intramolecular singlet energy transfer from oxadiazole or carbazole to naphthalimide was observed from the emission spectra of the dyad monomers and copolymers.