A white emitting copolymer with the polyphenylenevinylene (PPV) structure is obtained via the Stille cross-coupling reaction. Substitution of hydrogen atoms with fluorine atoms on the vinylene units of poly(1,4-dialkoxyphenylenevinylene) shifts the emission from orange-red to blue. White emission is obtained by combining dialkoxyphenylenedifluorovinylene and dialkoxyphenylenevinylene units in proper ratio. The two complementary emitters are obtained separately by Stille polymerization reaction. Then, the two reaction mixtures are combined without purification in different ratios and further reacted in similar experimental conditions. A white luminescent material is obtained using 99/1 mixing ratio. OLED devices fabricated with this copolymer shows near-white emission with CIE (0.30, 0.40) and excellent stability in the range 10e200 cd/m2.

An alkoxy-substituted poly(phenylene thiophene) is used in order to suspend single-walled carbon nanotubes in an organic solvent. The suspension is spread on the air–water interface of a Langmuir trough and the floating film is characterized by means of Brewster angle microscopy and UV-visible reflection spectroscopy and the compression isotherm is recorded. The polymer/carbon-nanotube blend is transferred onto different substrates using the Langmuir–Blodgett technique. AFM measurements indicate the formation of globular structures for the samples transferred at low surfacepressure values and a tubular morphology for high-pressure-deposited samples. AFM analysis is repeated on a sample exposed to soft X-rays for about 5 h and a highly organized structure of bundles of carbon nanotubes rises up. Samples with different numbers of layers are transferred onto ITO substrates by means of the Langmuir–Blodgett method and are tested as photocathodes in a photo-electrochemical cell. A Voc of 0.18 V, an Isc of 85.8mA, FF of 40.0%, and h of (6.23T103)% are obtained.

The use of an amphiphilic aryleneethynylene fluorophore as a plasma membrane marker in fixed and living mammalian cells and liposome model systems is demonstrated. We show here that the optical properties of the novel dye are almost independent on pH, in the range 5.0–8.0. Spectroscopic characterization performed on unilamellar liposomes ascertained that the fluorescence intensity of the aryleneethynylene fluorophore greatly increases after incorporation in lipidic membranes. Experiments performed on different mammalian cells demonstrated that the novel membrane marker exhibits fast staining and a good photostability that make it a suitable tool for live cell imaging. Importantly, the aryleneethynylene fluorophore was also shown to be a fast and reliable blue membrane marker in classical multicolor immunofluorescence experiments. This study adds new important findings to the recent exploitation of the wide class of aryleneethynylene molecules as luminescent markers for biological investigations.

The covalent functionalization of photosynthetic proteins with properly tailored organic molecular antennas represents a powerful approach to build a new generation of hybrid systems capable of exploiting solar energy. In this paper the strategy for the synthesis of the tailored aryleneethynylene organic fluorophore (AE) properly designed to act as light harvesting antenna is presented along with its successful bioconjugation to the photosynthetic reaction center RC from the bacterium Rhodobacter sphaeroides .

The aggregation behavior of two D-glucose-substituted phenyleneethynylenes, an alternate copolymer (AP) and a homooligomer (HO), has been investigated by means of UV−vis absorption, circular dichroism (CD) and fluorescence spectroscopy. CD reveals superior capability to detect the early stages of aggregation and to provide information about aggregate geometries. The multiband CD spectrum of the AP and of analogous chiral PPEs is rationalized on the basis of the exciton coupling between vibronic transitions localized on proximate portions of the chromophoric chains.

Ternary blends comprising an ‘energy-cascade former’ in addition to the donor and the acceptor materials increasingly attract attention in the organic solar cell area as they seem to provide a tool to positively manipulate the open-circuit voltage of bulk-heterojunction devices. By comparing two additives that have similar HOMO/LUMO levels and that can be expected to lead to an energy cascade in ternaries with the prototypical P3HT:PC60BM system, we demonstrate here that the compatibility of the additive with, in this specific case, the fullerene, that can be tailored by peripheral chemical functionalization, plays a critical role in energy cascade formation. A compromise needs to be found between good mixing (favoring energy cascade formation) and phase separation (supporting charge extraction) that affect the open-circuit voltage in an as important fashion as their electronic features, providing critical insights for future materials design activities.

White organic light emitting diodes (WOLEDs) are promising devices for application in low energy consumption lighting since they combine the potentialities of high efficiency and inexpensive production with the appealing features of large surfaces emitting good quality white light. However, lifetime, performances and costs still have to be optimized to make WOLEDs commercially competitive as alternative lighting sources. Development of efficient and stable emitters plays a key role in the progress of WOLED technology. This tutorial review discusses the main approaches to obtain white electroluminescence with organic and organometallic emitters. Representative examples of each method are reported highlighting the most significant achievements together with open issues and challenges to be faced by future research.

Light machine: The simplest photosynthetic protein able to convert sunlight in other energy forms is covalently functionalized with a tailored organic dye to obtain a fully functional hybrid complex that outperforms the natural system in light harvesting and conversion ability.

Fluorination has become a versatile route to tune the electronic and optical properties of organic conjugated materials. Herein we report a new phenomenon, excited-state switching by per-fluorination of para-oligophenylenes, placing a low intensity 11B2 state below the 11B1 state, giving rise to large Stokes shifts. The switching is attributed to the specific impact of fluorine on the delocalized and localized frontier orbitals as elucidated by quantum-chemical calculations. The sterical demands of the fluorine atom additionally diminish efficient conjugation along the chain, leading to hypsochromic shifts with respect to the unsubstituted counterparts and to a weak chain length dependence of the absorption and unstructured emission spectra and enhanced internal conversion.

This review is an overview of our previous work on the synthesis and properties of poly(p-phenylenevinylene)s (PPVs) selectively fluorinated in different positions of the conjugated backbone. Both the synthetic challenges and the effects of functionalization with fluorine atoms on the optical behavior are discussed, highlighting the peculiarities and the interest of this class of conjugated polymers. A general polymerization protocol for PPVs, that is based on the Pd-catalyzed Stille cross-coupling reaction of bis-stannylated vinylene monomers with aromatic bis-halides, has been successfully extended to the synthesis of selectively fluorinated poly(p-phenylenevinylene)s. The properties of a series of these PPVs differing in the number and positions of the fluorine atoms on the conjugated backbone have been studied, even in comparison with the non-fluorinated counterparts. The intriguing optical features of the resulting materials are discussed considering not only the role of the electronic and steric effects induced by the fluorine substituents, but also the impact of the fluorination on the solid state organization and intermolecular interactions.

A low band-gap copolymer PDTBTFV alternating bis-thienyl-(bis-alkoxy)-benzothiadiazole blocks with difluorovinylene units and its non-fluorinated counterpart PDTBTV have been synthesized and characterized as donor materials in bulk heterojunction (BHJ) solar cells with PCBM as the acceptor. The solar cells with the fluorinated polymer show better photovoltaic performances than those recorded with the non-fluorinated material. Comparative spectroscopic and computational studies, together with morphological, electrical and optical characterization of thin films, have been carried out to shed light on the reasons for the improvement of performances as induced by the double bond fluorination. Our study introduces the fluorinated double bond as a new conjugated unit in donor polymers for BHJ solar cells.

Hysteresis behaviour of the current-voltage characteristics collected on spin coated synthetic eumelanin layer embedded in the Au/eumelanin/ITO/glass structure is shown. The effect has been observed under dark both in air and vacuum environment and its magnitude has been found related to the eumelanin hydration state. Moreover, in vacuum and under white light illumination, enhancement of the hysteresis loop area respect to those collected under dark has been observed. Space charge storage and charge trapping/detrapping as possible mechanisms responsible of the observed current-voltage behaviour are discussed. Preliminary experimental results have evidenced the possible integration of eumelanin layers in electro-optical charge storage based memory devices. (C) 2010 Elsevier B.V. All rights reserved.

Hysteresis behaviour of the current–voltage characteristics collected on spin coated synthetic eumelanin layer embedded in the Au/eumelanin/ITO/glass structure is shown. The effect has been observed under dark both in air and vacuum environment and its magnitude has been found related to the eumelanin hydration state. Moreover, in vacuum and under white light illumination, enhancement of the hysteresis loop area respect to those collected under dark has been observed. Space charge storage and charge trapping/detrapping as possible mechanisms responsible of the observed current–voltage behaviour are discussed. Preliminary experimental results have evidenced the possible integration of eumelanin layers in electro-optical charge storage based memory devices.

application in organic polymer solar cells. A large variety of low bandgap polymers are prepared by alternating copolymerization of electron-donating donor and electron-withdrawing acceptor units. The interaction between these two units can reduce the polymer bandgap, increasing the sunlight absorption. Benzothiadiazole is commonly used as acceptor block unit in low bandgap polymers. In this contribution we investigate the supramolecular organization and optical properties of thin films of conjugated polymers consisting of benzothiadiazole and thiophene with electron-withdrawing difluorovinylene, and electron-donating vinylene substituents. Atomic force microscopy and spectroscopic ellipsometry are exploited for the analysis of the morphology and optical transitions, respectively. It is found that F-atoms in the vinylene unit yield a blue-shift of the absorption peaks of 0.2 eV respect to the hydrogenated polymer and an increase in the absorption coefficient of fluorinated polymers, which indicates their potential application as photovoltaic material. The morphology evolution of the conjugated polymers blended with a fullerene derivate ([6,6]-phenyl C61-butyric acid methyl ester, PCBM) is also investigated by atomic force microscopy.???

We describe the synthesis of two novel poly(1,4-arylene-2,5-thienylene)s P1 and P2 containing benzo[c][2,1,3]thiadiazole monomeric units via Suzuki–Miyaura polymerization of a thiophene diboronic ester with aryl diiodides. The use of a catalyst complex consisting of Pd(OAc)2 in combination with the electron-rich biaryl phosphine S-Phos resulted in efficient polymerization reactions. The polymers synthesized, P1 and P2, were characterized by UV–vis spectroscopy and cyclic voltammetry. Theoretical calculations and electrochemical measurements on P1 suggested a favorable position of the molecular orbitals for employment in polymer solar cells in combination with PCBM. Devices containing P1:PCBM 1:2 in the active layer showed an efficiency of 1.2% by simple spin casting from chloroform.

Synthetic melanin based metal-insulator-semiconductor devices are fabricated for the first time thanks to silicon surface wettability modification by using dielectric barrier discharge plasma. Ambipolar charge trapping in air and ion drift mechanisms under vacuum are identified by capacitance-voltage hysteresis loops. These results aim to foresee the possible integration of synthetic melanin layers as a novel capacitor in organic polymer based devices.

The electrical transport across a biomimetic interface made up of spin coated melanin layers on nanotextured silicon surfaces with different texturing features and wetting properties is discussed. Nanotexturing allows, under certain conditions, the melanin better anchoring on a hydrophobic silicon surface, overcoming the hydrophilic melanin-hydrophobic silicon interface criticism. The feature of the electrical signal transduction across such a structure was studied by impedance spectroscopy and found to be influenced by the nano-texturing chemistry and surface morphology. The effects of a voltage pulse, as external stimulus modifying the electrical transport mechanisms and retention of the subsequently achieved carrier transport conditions have been elucidated. The results let to foresee a possible exploiting of this circuital element for bio and environmental molecules sensing.

Organic field-effect transistors (OFETs) are key devices in organic electronics, and their performances largely depend on molecular structure and solid-state organization of the π-conjugated compounds used as semiconductors. This microreview reports several examples of materials for OFET devices and sensors, which have been selected to highlight the basic criteria of molecular design together with the synthetic logic driving the development of organic semiconductors. Versatile synthetic methodologies enable to optimize properties by tailoring molecular structures and functionalization, thus playing a key role in the progress of OFET technology, and more in general of organic electronics, which is emphasized in the discussion.

A new set of linear oligoarylene thiol molecules, namely (4'-(Thiophen-2-yl) Biphenyl-3,5-diyl) Dimethanethiol (TBD), (4'-(Thiophen-2-yl) Biphenyl-4-yl) Methanethiol (TBM) and ([ 1,1'; 4',1''] Terphenyl-3,5-diyl) Dimethanethiol (TD), were synthesized and used for functionalizing the polycrystalline gold electrodes. Such molecules differ for the number of anchoring groups (TBM vs. TBD) and the terminal rings (TD vs. TBD). As shown by electrochemical measurements, they form homogeneous and pinholes-free self-assembly monolayers (SAMs) when deposited on the gold electrode. Moreover, the wettability of the functionalized surface and the morphological changes of pentacene films grown on SAMs were investigated by contact angle and atomic force microscopy, respectively. OTFT has been used as organic gauge for investigating the metal-SAM-organic semiconductor structure. Charge carriers mobility, threshold voltage, contact resistance were measured in both air and vacuum to assess the influence of the anchoring groups and the terminal rings to the transistor performance. Although these SAMs do not show an improvement of mobility due to an increase of contact resistance, they allow a better modulation of the current flowing across the electrode-organic semiconductor (OS) interface, pointing out the structural differences between the three SAMs in terms of resistance drop combined with the critical voltage.

White organic light emitting diodes (WOLEDs) represent a promising alternative to incandescent or fluorescent lamps and inorganic LEDs for low energy consumption lighting applications. WOLEDs combine the potentialities of high white color quality and low production costs with the distinctive feature of being available also as flexible and large area devices. Moreover, fine control of white color quality can be easily achieved by proper chemical design of organic electroluminescent materials. Here we survey the main chemical approaches to white organic electroluminescence, highlighting strong and weak points of each strategy.

An overview of the organometallic synthetic approaches to low-band-gap polymers for organic solar cells from 2008 to the present is reported. The key role of the synthetic methods in development of materials with increasing performances is outlined, with consideration not only of research laboratory criteria, but also of parameters relevant to mass production: synthetic complexity, amount and toxicity of reactants and by-products, and purification steps. The review is organized into sections covering the different organometallic polymerization reactions, also including olefin metathesis and the most recent results on direct arylation processes that appear particularly promising in terms of reduced synthetic complexity, costs, and byproducts. In the last section of the review, the discussed synthetic methods are reconsidered from the perspective of industrial scalability, which is one of the most critical issues for making OPV technology an effective route to solar energy exploitation. Interesting considerations are drawn on these basis, and directions for future developments in terms of requirements of the synthetic protocols are outlined.

Palladium-promoted cross-dimerization reaction of alkenylsilanes is reported for the first time, which is also one of the very first studies on oxidative cross-coupling between vinylic organometallic reagents. The reaction occurs at room temperature in aqueous micelles and represents a convenient access to alltrans pushepull butadienes.

Palladium-promoted homocoupling reaction of vinyl- and polyenylsilanes in aqueous conditions has been investigated. The reaction is catalyzed by PdCl2 in the presence of the reoxidizing system CuCl2/LiCl and occurs at room temperature in aqueous solutions containing nonionic amphiphiles. Symmetrically α,ω-disubstituted stereodefined all-trans polyenes have been obtained in mild conditions and in good yields (65–87%), higher than those previously reported for the same reactions carried out in methanol or HMPA. A comparison between two commercially available surfactants, Triton X-100 and PTS, has been performed.

Several organometallic methods are used to synthesize pi-conjugated molecules and polymers with alternating thiophene-dialkoxyphenylene units in the conjugated backbone. Here we describe our approaches to the synthesis of materials based on the dialkoxyphenylenethienylene structural motif via palladium catalyzed cross-coupling reactions of organomagnesium or organoboron reagents with aryl halides. The properties of the resulting compounds and their applications in (opto)electronic devices (organic field effect transistors, resistive gas sensors, field effect chiral sensors, photoelectrochemical cells and bulk-heterojunction solar cells) are also discussed, highlighting the role of the synthetic logic in the design of multifunctional organic materials.

Four thiolated oligoarylene molecules (i) 4- methoxy-terphenyl-4″-methanethiol (MTM), (ii) 4-methoxyterphenyl- 3″,5″-dimethanethiol (MTD), (iii) 4-nitro-terphenyl- 4″-methanethiol (NTM), and (iv) 4-nitro-terphenyl-3″,5″- dimethanethiol (NTD) were synthesized and self-assembled as monolayers (SAMs) on polycrystalline Au electrodes of organic field-effect transistors (OFETs). SAMs were characterized by contact angle and AC/DC electrochemical measurements, whereas atomic force microscopy was used for imaging the pentacene films grown on the coated electrodes. The electrical properties of functionalized OFETs, the electrochemical SAMs features and the morphology of pentacene films were correlated to the molecular organization of the thiolated oligoarylenes on Au, as calculated by means of the density functional theory. This multi-methodological approach allows us to associate the systematic replacement of the SAM anchoring head group (viz. methanethiol and dimethanethiol) and/or terminal tail group (viz. nitro-, −NO2, and methoxy, −OCH3) with the change of the electrical features. The dimethanethiol head group endows SAMs with higher resistive features along with higher surface tensions compared with methanethiol. Furthermore, the different number of thiolated heads affects the kinetics of Au passivation as well as the pentacene morphology. On the other hand, the nitro group confers further distinctive properties, such as the positive shift of both threshold and critical voltages of OFETs with respect to the methoxy one. The latter experimental evidence arise from its electron-withdrawing capability, which has been verified by both DFT calculations and DC electrochemical measurements.

Colloidal white emitting nanostructures were successfully fabricated by covalently binding a blue emitting oligofluorene at the surface of silica beads, that incorporate orange luminescent colloidal CdSe@ZnS quantum dots (QDs). White light was achieved by carefully tuning the size of the QDs to complementarily match the emission color of the blue fluorophore and taking into account the delicate balance between the emission of the QDs in the core of the silica beads and the amount of the organic dye bound to the silica surface. The proposed approach is highly versatile as it can be extended to the fabrication of a variety of luminescent hybrid nano-objects, playing with the complementarity of the emission color of the inorganic and organic fluorophores at the nanoscale.

Anthocyanins, extracted from grape skin (Vitis vinifera), were dissolved in ultrapure aqueous subphase and an oligophenylenevinylene derivative was spread on the subphase surface. Such oligomer was chosen as anionic counterpart of hydrosoluble anthocyanins in order to perform a Langmuir-Schafer film of the dyad. Interface interactions between oligophenylenevinylene derivative and anthocyanins were studied by Brewster angle microscopy and reflection spectroscopy. Additionally, the oligomer exhibits a chemical structure able to ensure an enhancement of the stability under UV-visible irradiations of the film of the dyad without any variation of the natural pigment absorption in the visible range. The visible spectra of cast anthocyanins film and Langmuir-Schafer oligomer/anthocyanins film after exposure to 254 nm irradiation showed a remarkable increase of the film stability, probably due to the screening effect of the oligomer. Preliminary test of a Langmuir-Schafer film of oligophenylenevinylene derivative/anthocyanins as a herbicide sensor showed that sensing is completely reversible, stable and repeatable. (C) 2011 Elsevier Ltd. All rights reserved.

Fully fluorinated arylenevinylene polymers have been synthesized via a methodology based on the Stille cross-coupling reaction and characterized by FTIR spectroscopy and MALDI-TOF mass spectrometry. Investigation of thin film properties by cyclic voltammetry and ellipsometry shows that complete substitution of hydrogen atoms with fluorine atoms on the conjugated backbone of the poly(arylenevinylene) s results in a strong increase of the band gap.

The synthesis of two new dye families of croconic acid derivatives, semicroconaine and non-symmetric croconaine dyes, is reported for the first time. These compounds show strong absorption in the UV-visible and NIR, respectively. Semicrocon-aine dyes were obtained by a scalable and efficient condensation of croconic acid with aromatic heterocyclic methylene-active compounds. The subsequent reaction of the semicroconaine dyes with aromatic heterocyclic compounds affords non-symmetric croconaines. The structure and electronic properties of the synthesized compounds have been investigated by preliminary theoretical calculations at DFT level of approximation.

A general method to synthesize conjugated molecules with a benzofulvene core is reported. Up to four conjugated substituents have been introduced via a three-step sequence including (1) synthesis of 1,2-bis(arylethynyl)- benzenes; (2) exo-dig electrophilic cyclization promoted by iodine; and (3) cross-coupling reaction of the resulting bisiodobenzofulvenes with organoboron, organotin, or ethynyl derivatives under Pd catalysis. Structural aspects of the new compounds are discussed.

Phenylene-thiophene oligomers bearing peracetylated beta-D-glucose or N-BOC-L-phenylalanine as chiral substituents were synthesized in good yields by a versatile protocol based on the Suzuki-Miyaura cross-coupling reaction. Aryl iodides bearing the chiral biomolecules as substituents efficiently reacted with pinacol boronates of bi- or terthiophenes leading to the bio-functionalized oligomers in good yields.

This chapter discusses the most important synthetic routes to the main classes of electroluminescent -conjugated polymers, highlighting advantages and limitations of the different methods in terms of versatility, stereo- and regioselectivity, efficiency. The discussion covers not only the synthesis of basic classes of polymers such as polyarylenes, poly(arylenevinylene)s, poly(aryleneethynylene)s, but describes routes to systems with more complex structures, including multifunctional copolymers and coordination polymers.

In this article we discuss synthetic routes to organic conjugated oligomers and polymers bearing triple C-C bonds that have been recently developed in our laboratories, based on Pd-catalyzed Csp-Csp2 coupling reactions. Experimental protocols have been tuned to face synthetic challenges such as the presence in the main conjugated backbone of multifunctional substituents or

This review reports a survey of our recent results on the synthesis of arylenevinylene polymers and oligomers selectively functionalized with fluorine atoms on aromatic and/or vinylene units. The synthetic methods developed are based on Pd-catalyzed organometallic cross-coupling reactions and in particular on the Stille coupling between vinyl organotin derivatives and aromatic halides. Several compounds have been synthesized, which differ for the number and position of the fluorine atoms on the conjugated backbone, even combined with other functional groups. The effects of fluorination on optical properties both in solution and solid state are discussed.

A novel class of tetrathiolated aryleneethynylene oligomers was obtained by the Cassar–Heck–Sonogashira coupling between S,S'-(5-ethynyl-1,3-phenylene)bis(methylene)diethanethioate (1) and aryl diiodides or dibromides. Although standard coupling conditions are effective in the case of iodo derivatives, the addition of free triphenylphosphane to the reaction mixture was required to overcome the slower reaction rate of dibromoarenes. Oligomers with an extended conjugated system could be obtained starting from a higher homologue of 1 by applying the same synthetic approach. These oligomers represent interesting molecular wires, potentially able to self-assemble on various substrates, including gold and other noble metals in the form of thin films or nanoparticles. The chelating arrangement of the thiol functionalities should ensure stable anchoring and would also represent an interesting novel feature in the study of single molecule conduction with respect to traditional monodentate systems.

In this review the main synthetic aspects and properties of fluorinated arylenevinylene compounds, both oligomers and polymers, are summarized and analyzed. Starting from vinyl organotin derivatives and aryl halides, the Stille cross-coupling reaction has been successfully applied as a versatile synthetic protocol to prepare a wide series of -conjugated compounds, selectively fluorinated on the aromatic and/or vinylene units. The impact of fluoro-functionalization on properties, the solid state organization and intermolecular interactions of the synthesized compounds are discussed, also in comparison with the non-fluorinated counterparts. Luminescent and photovoltaic applications are also discussed highlighting the role of fluorine on the performance of devices

Self-assembled monolayers (SAMs) derived of 4-methoxy-terphenyl-300,500-dimethanethiol (TPDMT) and 4-methoxyterphenyl- 400-methanethiol (TPMT) have been prepared by chemisorption from solution onto gold thin films and nanoparticles. The SAMs have been characterized by spectroscopic ellipsometry, Raman spectroscopy and atomic force microscopy to determine their optical properties, namely the refractive index and extinction coefficient, in an extended spectral range of 0.75-6.5 eV. From the analysis of the optical data, information on SAMs structural organization has been inferred. Comparison of SAMs generated from the above aromatic thiols to well-known SAMs generated from the alkanethiol dodecanethiol revealed that the former aromatic SAMs are densely packed and highly vertically oriented, with a slightly higher packing density and a absence of molecular inclination in TPMT/Au. The thermal behavior of SAMs has also been monitored using ellipsometry in the temperature range 25-500 C. Gold nanoparticles functionalized by the same aromatic thiols have also been discussed for surface enhanced Raman spectroscopy applications. This study represents a step forward tailoring the optical and thermal behavior of surfaces as well as nanoparticles.

The title complex, [Ir2(C18H13FNO2S)4Cl2]C7H8, was crystallized from dichloromethane solution under a toluene atmosphere. It is a dimeric complex in which each of the two IrII centres is octahedrally coordinated by two bridging chloride ligands and by two chelating cyclometallated 2-(5-benzylsulfonyl)- 3-fluoro-2-(pyridin-2-yl)phenyl ligands. The crystal structure analysis unequivocally establishes the trans disposition of the two cyclometallated ligands bound to each IrII centre, contrary to our previous hypothesis of a cis disposition. The latter was based on the 1H NMR spectra of a series of dimeric benzylsulfonyl-functionalized dichloride-bridged iridium complexes, including the compound described in the present work [Ragni et al. (2009). Chem. Eur. J. 15, 136–148]. The toluene solvent molecules, embedded in cavities in the crystal structure, are highly disordered and could not be modelled successfully; their contribution was removed from the refinement using the SQUEEZE routine in the program PLATON [Spek (2009). Acta Cryst. D65, 148–155].

Alkyl thiols are processing additives for bulk heterojunction (BHJ) solar cells useful for substituting post-production treatment with low energy consuming processes (1). They modify the solubility of donor:acceptor couple in the host solvent, impacting solid state nanoscale phase separation. After deposition, thiol solvent presumably evaporates from the blend. Conjugated structures with pending alkylthiol groups could be interesting for ternary blend (2) polymer solar cells. Such materials could not only optimize the active layer morphology, but contribute by means of their conjugated structure to light harvesting and charge generation processes operating in the solar cell. Building on our experience in the synthesis of thiolated materials (3), we recently synthesized a family of organic semiconductors with low bandgap and pending alkylthiol groups. Their study in all organic or hybrid nanostructures represents an unexplored dimension in new generation photovoltaics. We present their synthesis and demonstrate the photovoltaic response of one of these compounds employed as additive in P3HT:PCBM solar cells. (1) Solar Energy 2011, 85,1226; (2) Adv. Mater. 2013, 25, 4245; (3) J. Org. Chem. 2007,72, 10272; Eur. J. Org. Chem. 2011, 529; Curr. Org. Synth., 2012, 9, 764.

In a recent report (Eur. J. Org. Chem. 2014, 30, 6583) we emphasized the importance of addressing research efforts in OPV-active materials toward synthetic processes scalable up to industrial production. In this context, palladiumcatalyzed direct (hetero)arylation polymerization (DHAP) can be a suitable approach to reduce the number of reaction steps and to avoid the use of toxic reagents in the synthesis of donor polymers. Random donor−acceptor copolymers have been shown to be promising materials for bulk heterojunction (BHJ) solar cells with high efficiencies and increased thermal stability. We report here the synthesis by DHAP of a ternary double-acceptor/donor random copolymer including benzo[c][1,2,5]thiadiazole and benzo[d][1,2,3]triazole as the accepting units and benzo[1,2-b;4,5-b′]dithiophene as the donor moiety. The results are discussed in comparison with the synthesis of the same polymer via the Stille polymerization. The coupling products formed in the early stage of the polycondensation have been isolated and characterized by NMR spectroscopy to gain insight into the regiochemistry of DHAP. The polymers synthesized have been tested in BHJ solar cells with PC71BM as the electron acceptor material. Power conversion efficiencies (up to 2.8%) are comparable or lower (depending on the processing conditions) than those of the same polymer synthesized via the Stille coupling reaction; however, the DHAP protocol is more convenient in terms of synthetic complexity.

La presente invenzione riguarda dispositivi sensori analiti gassosi comprendenti transistor a film sottile organico e, in particolare, sensori in grado di effettuare la discriminazione enantiomerica di analiti gassosi. I film sottili organici sono caratterizzati dal fatto di comprendere un composto di formula (I).

This invention pertains to gaseous analytes sensor devices comprising organic thin film transistor and, in particular sensors able to perform the enantiomeric discrimination of gaseous analytes. The organic thin films are characterized by comprising a compound of formula (I).