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The technology of organometal halide perovskites is on the verge of the lab to fab transition due to particularly high efficiencies and low cost of the raw materials employed in the active later. The hole transport layer is a key enabling component of such solar cells and at the same time the one requiring more significant synthetic efforts. Alternative materials with improved sustainability are under constant development, yet 2,2′,7,7′-tetrakis(N,N-di(4-methoxyphenyl)amino)-9,9′-spirobifluorene (Spiro-OMeTAD) still represents the standard in the field. We show that the combination of solventless approaches, chemistry on water, and micellar catalysis gives access to such critical material in a fully sustainable, scalable, and efficient way. Performances are validated in devices delivering results equal to those with standard commercial Spiro-OMeTAD but greatly reducing the overall E-factor─a green chemistry metric measuring the waste/purified product ratio of a synthesis, from 5299 to 555, as well as eliminating chlorinated solvents and hazardous chemicals.

Cesium lead halide perovskite nanocrystals of general formula CsPbX3 are having tremendous impact on a vast array of technologies requiring strong and tunable luminescence across the visible range and solutions processing. The development of plastic scintillators is just one of the many relevant applications. The syntheses are relatively simple but generally unsuitable to produce a large amount of material of reproducible quality required when moving from proof-of-concept scale to industrial applications. Wastes, particularly large amounts of lead-contaminated toxic and flammable organic solvents, are also an open issue. We describe a simple and reproducible procedure enabling the synthesis of luminescent CsPbX3 nanobricks of constant quality on a scale going from 0.12 to 8 g in a single batch. We also show complete recycling of the reaction wastes, leading to dramatically improved efficiency and sustainability.

Micellar catalysis is playing a major role in green chemistry with ever increasing applications in the efficient and sustainable preparation of natural compounds, drugs, and more recently organic semiconductors for printed electronics. Most of the contributions in the field focus on the developments of surfactants and suitable formulative conditions capable of reproducing – and often improving – the yield of reactions commonly performed in organic solvents. The real ambition of the micellar catalysis approach goes beyond the improvement in the sustainability of existing methods and aims at mimicking not only the efficiency but also the selectivity of enzymatic catalysis. This review summarizes relevant examples of micellar catalysis enabled, efficient, and selective transformations, and discusses the different kind of processes impacting on the product distribution depending on the details of the formulative state achieved.

Molecular doping enables increasing the conductivity of organic semiconductors and plays an increasingly important role in emerging and established plastic electronics applications. 1,3-Dimethyl-2-(4-(dimethylamino)phenyl)-2,4-dihydro-1H-benzoimidazole (N-DMBI-H) and tris(pentafluorophenyl)borane (BCF) are established n- and p-dopants, respectively, but neither functions as a simple one-electron redox agent. Molecular hydrogen has been proposed to be a byproduct of several mechanisms for doping using both DMBI-H and BCF. In this paper we show for the first time the direct detection of molecular hydrogen in the uncatalyzed doping of a variety of polymeric and molecular semiconductors using these dopants. Our results provide insight in the doping mechanism, providing information complementary to that obtained from more commonly applied methods such as optical, electron spin resonance, and electrical measurements.

The Suzuki-Miyaura reaction between the aryl halide (1) and the phenyl boronic acid (2), in the presence of the palladium(0) complex (3) as catalyst, gives the cross-coupling product (4) in quantitative yield when performed in basic aqueous solution of the nonionic surfactant Kolliphor-EL (K-EL). The partition between the aqueous and micellar environments of the species of this reaction has been investigated by means of Molecular Dynamics (MD) simulations. Starting from the K-EL molecules dispersed in water, a micelle model has been generated by MD simulations, adopting the 2016H66 force field. Reagent and product species have been described with the same force field, once the reliability of this force field has been tested comparing the n-octanol/water partition free energies calculated from the MD and Free Energy Perturbation (FEP) method with those obtained from the quantum-mechanical SMD method. The potential of mean force for the transfer process between water and the micellar phase of the different species has been calculated by the MD simulations and the Umbrella Sampling (US) method. The overall picture that emerges from these results confirms that the molecular species involved in this reaction prefers the micellar environment and concentrates in different but close zones of the micelle. This supports the experimental evidence that the use of suitable surfactant agents promotes reactivity, allowing micelles to behave as nanoreactors in which reactive species are solubilized and enhance their local concentration.

Here, we report a [1]benzothieno[3,2-b][1]-benzothiophene (BTBT) derivative functionalized with a β-sheet-forming peptide which alternates in its sequence Phe and Glu residues. The BTBT core is a popular structural motif in the design of high-mobility organic semiconductors. The insertion of the self-assembling subunit allows control of the supramolecular organization. This molecule self-assembles in water to give hydrogels over a broad range of pH values. Hydrogelation is triggered by both pH changes and variations in salt concentrations. Transmission electron microscopy shows the formation of long-range self-assembled 1D structures. The key role of hydrogen bonding and π-π interactions in hierarchical self-assembly is investigated using absorption, emission, infrared and circular dichroism spectroscopy. This is the first example of demonstrating the formation of supramolecular hydrogels containing the BTBT structure.

The asymmetric n-type Ph-BTBT-C10 derivative 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene S,S,S′,S′-tetraoxide is structurally investigated in the thin film regime. After film preparation by spin coating and physical vapor deposition, a rather disordered structure is observed, with a strong change of its internal degree of order upon heating. At 95 °C, a transition into a layered structure of upright standing molecules without any in-plane order appears, and at 135 °C, crystallization takes place. This phase information is combined with surface morphological studies and charge carrier mobility measurements to describe the structure and thin film transistor applicability of this molecule.

Luminescent solar concentrators (LSCs) have recently emerged as valuable candidates for the realization of aesthetically pleasing solar windows for near-zero-energy consumption buildings. The growing demand by the building-integrated photovoltaic sector is urging the development of sustainable production methods that minimize the use of polluting organic solvents and hazardous materials, while still enabling industrial-grade LSCs. Here, we introduce a new class of benzothieno-benzothiophene (BTBT) derivatives as highly efficient reabsorption-free emitters for transparent LSCs featuring high stability and a solvent-free chemical access with sustainability factor as low as 21, 10 to 50 times lower than conventional LSC emitters. By embedding our BTBT emitters in optical-grade polymeric waveguides, we produced large-area (40 cm × 40 cm) LSCs with optical power efficiency as high as 3% (corresponding to an optical quantum efficiency of 54%). These results represent an important advancement toward sustainable solar glazing systems for green architecture.The growing demand for building-integrated photovoltaic technologies for near-zero-energy buildings is motivating the scientific community to develop devices that meet the functional, energetic, and aesthetic needs for sustainable architecture. Luminescent solar concentrators (LSCs) are emerging as valuable solutions to realize aesthetically pleasing semitransparent photovoltaic windows capable of converting urban buildings into energy generators. In this work, we report on efficient, transparent LSCs based on a novel class of reabsorption-free derivatives synthesized through a solvent-free route that massively improves the sustainability factor with respect to the state of the art. Optical-grade polymeric LSCs are produced via industrial methods with an optical power efficiency as high as 3% despite their transparency in the visible region. These results represent an important step forward for sustainable solar glazing systems for environmentally friendly architecture. Efficient and aesthetically pleasing solar technologies, such as LSC photovoltaic windows, are becoming essential for the widespread of zero-energy buildings. The more the LSC technology gains appeal, the higher the need becomes for efficient and sustainable materials and production routes. Through a new mechanochemical route, we produce efficient, reabsorption-free LSC emitters with a massively increased sustainability factor. The integration of such derivatives into industrial-grade LSCs leads to an optical efficiency of 3% for large-area devices.

The study of manufacture technologies and provenance of raw materials in archaeological potteries are two fundamental aspects in providing information about sociocultural aspects on past societies. The most acknowledged technique in this field is represented by minero‐petrographic analysis, allowing to describe the compositional features of the artefacts and to link them to geological outcrops and technologic processes. In the case of fine‐grained potteries, minero‐petrographic analysis might sometime give back not clear results, requiring the use of high‐resolved methods. In this framework, information about raw materials and firing techniques might be provided by the support of micro‐Raman spectroscopy, able to supply information on mineral grains not detectable under a microscope and for which powders diffraction methods are not able to provide unique interpretations. In this work, particular attention was devoted to the phases formed during the ceramic body annealing, especially to newly formed feldspars, exhibiting a not natural occurring composition. Their correct identification, important for thermometric studies, is possible only with the use different techniques, due to the different investigated aspects (structure, composition and lattice dynamics). Fine‐grained potteries from the famous site of Volterra, Tuscany (Italy) have been characterized as case study during a comparative evaluation of the results obtained by different techniques (micro‐Raman analysis, optical microscopy [OM], X‐ray diffraction [XRD] and scanning electron microscope energy dispersive spectrometry [SEM‐EDS]) on the same mineral grains. The obtained results demonstrated how micro‐Raman spectroscopy might improve interpretation of data collected with different methods in several aspects, from provenance to firing temperature estimation.

The impact on chiral aggregation in solution processed and thermally annealed thin films of two indolenine and one anilino squaraines with chiral (S)-citronellyl functionalization at the nitrogen of the squaraine backbone is investigated. A pseudo polymorphic crystal structure is obtained for one of the indolenine squaraines, but thin films of both compounds are basically non-aggregated and truly isotropic as evidenced by spectroscopic ellipsometry. The anilino squaraine coalesces and readily aggregates to circular dichroic but discontinuous thin films. The extent of circular dichroism correlates with the morphology of the samples, which is quantified by Mueller matrix polarimetry in combination with atomic force microscopy. The shape of the CD spectra reinforces the hybrid Frenkel and charge-transfer excitonic nature of the characteristic double hump signatures within unpolarized absorbance spectra of previously investigated non-chiral anilino squaraines with linear alkyl chain functionalization. Such excitonic CD offers an additional design parameter for next-generation opto-electronic devices.

Perovskite solar cells (PSCs) are experiencing tremendous interest due to compatibility with solution processing on a wide range of substrates and very high efficiency. The hole transport layer (HTL) plays a fundamental role in such multistack cells. We propose new branched and polymeric organic HTL derivatives with sustainable synthesis and performances exceeding those of Spiro-OMeTAD, the standard in the field.

Quadruple addition of phenyl groups to a diphenylpyridylmethane skeleton was achieved. The derived (3,5-difluoro-4-pyridyl)bis(2,6-dichloro-3,4-diphenylphenyl)methyl radical (Ph4-F2PyBTM) displayed superior luminescence properties to the previously reported organic diphenylpyridylmethyl radicals in various organic solutions at room temperature, and it reached 33% photoluminescence quantum efficiency in PMMA film. With the introduction of methoxy groups, quadruple adduct (MeOPh)4-F2PyBTM and triple adduct (MeOPh)3-F2PyBTM were isolated. The excited state of these radicals showed an intramolecular charge transfer character and efficient fluorescence only in nonpolar solvents. The radicals retained not only persistency at the ground state but also durability under photoirradiation, with a 6 to 14 fold improved photostability with respect to the original PyBTM.

Micellar catalysis is having a dramatic impact in improving the sustainability of a wide variety of chemical transformations, including most of the popular palladium mediated carbon–carbon and carbon–nitrogen bond forming reactions. The Suzuki-Miyaura coupling is one of the earliest examples of micellar catalyzed reactions and it is still a very much active research field even at industrial scale. So far, micellar catalysis proved particularly efficient in enabling the high yield, low catalyst loading and mild reaction condition coupling of hydrophobic reagents in a water solution of selected surfactants. In this paper we show that the use of aqueous solutions of a mixture of food grade lecithin and the industrial surfactant Tween 80 not only enables efficient coupling in water of hydrophobic chemicals, but also provides a very resourceful tool for the functionalization of water and organic solvent insoluble pigments of interest for the dye and printed electronic industries.

The photon upconversion based on sensitized triplet-triplet annihilation (sTTA-UC) is a spin-flip mechanism exploited to recover the energy stored on dark triplet states in conjugated systems. In this process, a high-energy fluorescent singlet is created through the collision and fusion of two low-energy triplets belonging to different diffusing molecules. Its high yield in solution under low excitation intensity and noncoherent light highlighted the huge potential of sTTA-UC to provide a breakthrough in solar technologies. However, its diffusion-limited nature restrains its efficiency in the solid state. To overcome this issue, we propose a single-molecule system that is able to host simultaneously more than one triplet, thus enabling a diffusion-free intramolecular TTA. We obtain the first direct demonstration of intramolecular triplet fusion by tailored photoluminescence spectroscopy experiments, thus opening the way to realize a new family of single-molecule upconverters with huge potential in solar and lighting technologies by accessing the natural triplets' energy reservoir.

A highly crystalline, highly emissive, and wide-bandgap polymer AC174 with an extremely small Stokes shift is designed and synthesized in water, and is used to reduce system energetic disorder and increase the exciton diffusion length of the classical PM6:Y6 blend system. AC174 is incompatible with PM6 and Y6, improves molecular packing, and reduces system energetic disorder. The long-range Förster resonance energy transfer between the donor and acceptor is enhanced, and the exciton diffusion constant and exciton lifetime are increased, leading to a longer exciton diffusion length and more efficient exciton dissociation and charge generation. The addition of AC174 simultaneously improves the open-circuit voltage, short-circuit current density (JSC) and fill factor of PM6:Y6 devices; especially the highest internal quantum efficiency approaches 100%, and the highest JSC is 28.4 mA cm−2. Ternary devices with 5% AC174 in the donors achieve a power conversion efficiency of 17.2%, higher than those of the parent binary devices based on PM6:Y6 (15.9%) and AC174:Y6 (3.24%).

Why is modern physics still today, more than 100 years after its birth, the privilege of an elite of scientists and unknown for the great majority of citizens? The answer is simple, since modern physics is in general not present in the standard physics curricula, except for some general outlines, in the final years of some secondary schools. But, is it possibile to teach modern physics in primary school? Is it effective? And, also, is it engaging for students? These are the simple questions which stimulated our research, based on an intervention performed in the last year of Italian primary school, focused on teaching gravity, according to the Einsteinian approach in the spirit of the Einstein First project, an international collaboration which aims to teach school age children the concepts of modern physics. The outcomes of our research study are in agreement with previous findings obtained in Australian schools, thus they contribute to validate them and show that there is no cultural effect, since the approach works in different education systems. Finally, our results are relevant also in terms of retention and prove that the students involved really understand the key ideas., 9 pages, 8 figures

4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-dimethylbenzenamine (DMBI-H) is a very successful dopant for n-type organic semiconductors. It is efficient over a large range of polymers and small molecule derivatives, commercially available, soluble in established processing solvents and generally considered to be air stable. Yet, on a closer look not all that glisters is gold. We show that DMBI-H does indeed decompose in the processing solvent, but the process does not negatively impact performances. Its main decomposition product acts as a nucleating agent for DMBI-H with the overall effect of boosting conductivity of the final doped P(NDI2OD-T2) films. Such results, confirmed by control experiments performed with a different nucleating agent, shine a light on the crucial role played by solid-state microstructure in DMBI-H doped semiconductors and hints a viable way to its optimization

Micellar catalysis enables carrying out Suzuki-Miyaura couplings in water under exceptionally mild conditions. Extension of such a protocol to the sustainable synthesis of highly conjugated, poorly soluble materials like [1]benzothieno[3,2-b][1]benzothiophene (BTBT) requires redesigning of the surfactants employed. The here reported new naphthalenediimide containing amphiphilic derivative, PiNap-750M, features unprecedented performances in the preparation of this and other relevant classes of organic semiconductors in water and at room temperature.

Carrying out photoredox direct arylation couplings between aryl halides and aryls in aqueous solutions of surfactants enables unprecedented selectivity with respect to the competing dehalogenation process, thanks to the partition coefficient of the selected sacrificial base. The use of a microfluidic reactor dramatically improves the reaction time, without eroding the yields and selectivity. The design of a metal free sensitizer, which also acts as the surfactant, sizeably improves the overall sustainability of arylation reactions and obviates the need for troublesome purification from traces of metal catalysts. The generality of the method is investigated over a range of halides carrying a selection of electron withdrawing and electron donating substituents.

Luminescent solar concentrators (LSCs) are becoming an increasingly relevant topic for building integrated photovoltaics. Even if such devices are relatively simple planar waveguides doped with a luminescent material, the achievement of relevant efficiencies requires a careful optimisation of both the matrix and the luminophore. Most of the recent literature focuses on the performance, yet the overall sustainability of the strategy is a topic at least as important. In this respect the luminophore plays a crucial role. Suitable materials must feature a near unit emission quantum yield, efficient light harvesting and a large separation between absorption and emission to reduce reabsorption losses. Due to the target application, such materials must also be readily available in large quantities through sustainable processes. Instead of going for performance first and then scaling up/optimising the synthesis, in this paper we offer a reversed perspective. We have first designed and computationally characterised materials having structural features compatible with a green chemistry synthetic approach, namely, micellar catalysis. Later, we have characterised the most promising materials in LSC devices, and we have compared their performance with commercially available, non-green chemistry compliant alternatives having similar spectral features. In the overall, we demonstrate comparable performance, but greatly improved sustainability and scalability. This journal is

Luminescent solar concentrators (LSCs) are rapidly emerging as the key enabling technology towards the realization of zero-energy buildings. The development of new efficient and sustainable luminophores is crucial for further improvement. The large Stokes shift, luminescent and persistent radicals prepared using sustainable routes offer advantages for large-area transparent LSCs featuring minimal colour distortion of the transmitted light. LSCs based on the best performing luminescent radicals are largely unaffected by reabsorption losses, thus providing a better performance with respect to the literature standards over active areas exceeding 400 cm2.

Direct (hetero)arylation (DHA) is playing a key role in improving the efficiency and atom economy of C&ndash, C cross coupling reactions, so has impacts in pharmaceutical and materials chemistry. Current research focuses on further improving the generality, efficiency and selectivity of the method through careful tuning of the reaction conditions and the catalytic system. Comparatively fewer studies are dedicated to the replacement of the high-boiling-point organic solvents dominating the field and affecting the overall sustainability of the method. We show herein that the use of a 9:1 v/v emulsion of an aqueous Kolliphor 2 wt% solution while having toluene as the reaction medium enables the preparation of relevant examples of thiophene-containing &pi, conjugated building blocks in high yield and purity.

We have investigated the atomistic structure and the electronic properties of selected metal-organic interfaces, commonly found in organic electronic devices, using ab initio simulations based on density functional theory. Our study focuses, in particular, on the interaction of a widely used p-type organic semiconductor (OS) like the [1]benzothieno[3,2-b][1]-benzothiophene (BTBT) polycyclic molecule with a gold electrode, bare or functionalized with a self-assembled monolayer (SAM) of aromatic thiol used as a surface modifier. A similar investigation involved an S,S'-tetraoxide derivative of BTBT indicated as BTBTOx(2), showing promising characteristics as an n-type semiconductor, whose original synthetic protocol is also discussed. First, our simulations, including the ab initio calculation of dispersion forces that permits an accurate description of noncovalent interactions, show that minimal changes in local interactions can induce a different arrangement of the same molecules in contact with metal electrodes. In particular, we report a stronger adhesion of BTBT and BTBTOx(2) on bare gold, with the molecules lying flat on the surface, and a stronger cohesion of the same organic adlayers on gold surfaces functionalized with an SAM, with the molecules that prefer to form stacks parallel to the surface, more similar to those observed in the corresponding molecular crystals. Moreover, the functionalization of the same gold surface with self-assembled molecular modifiers having different polarities induces changes in the electronic properties of the Au/BTBT and Au/BTBTOx(2) interfaces, transforming the Schottky junctions formed when the molecules are in direct contact with the bare gold surface in more favorable Au/SAM/OS junctions characterized by a significant reduction of the injection barrier or even a nearly Ohmic contact when the SAM is applied, in both the p-type and n-type investigated cases.

The use of water solutions of industrial and designer surfactants enables performing a wide variety of chemical transformation on hydrophobic precursors. Mostly reactions are clean, fast and efficient with vast benefits for overall sustainability. The widespread adoption of such methods is somewhat hampered by a lack of generality in the case of troublesome substrates and scaling up. The common literature solution for such issues is the use of small amounts of organic solvents. We here show that the use of a mixture of L-α-lecithin and Tween 80 is a preferable solution enabling the taming of particularly troublesome reactions, where even the cosolvent approach fails. The strong reduction of all interface tensions characterizing such complex multiphase systems is key to the results achieved. The protocol, applied to Suzuki-Miyaura couplings, allows to obtain complete reactions conversion at room temperature within one hour, is general and scalable from milligrams to up to 10 grams without further adjustments.

Conjugated semiconducting polymers are key materials enabling plastic (opto)electronic devices. Research in the field has a generally strong focus on the constant improvement of backbone structure and the resulting properties. Comparatively fewer studies are devoted to improving the sustainability of the synthetic route that leads to a material under scrutiny. Exemplified by the two established and commercially available luminescent polymers poly(9,9-dioctylfluorene-alt-bithiophene) (PF8T2) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (PF8BT), this work describes the first examples of efficient Suzuki-Miyaura polycondensations in water, under ambient environment, with minimal amount of organic solvent and with moderate heating. The synthetic approach enables a reduction of the E-factor (mass of organic waste/mass of product) by 1 order of magnitude, without negatively affecting molecular weight, dispersity, chemical structure, or photochemical stability of PF8T2 or PF8BT.

Latent pigments, a class of thermosensitive dyes that can be reverted to insoluble pigments via thermal treatment, are a well-established component of high performance inks which find uses in OLEDs and organic solar cells. Their synthesis is challenging due to the thermal sensitivity of the protection group. Cross coupling reactions in micellar environments enable synthesis at room temperature in water as the solvent. In the case of latent pigments, it was found that the use of a 10% by volume co-solvent in combination with a water solution of the cheap surfactant Kolliphor EL provides an excellent environment for Suzuki-Miyaura cross coupling with unprecedented yields and very short reaction times. Remarkably, reactions are insensitive to the atmosphere, affording excellent results both under nitrogen and oxygenated atmosphere.

Recrystallization from the melt of the n-type BTBT derivative 2-dectyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene S,S,S',S'-tetraoxide (Ph-BTBTOx2-10) reveals a defined crystal structure of the molecule. It leads to the formation of alternating nano-segregated layers consisting of parallelly stacked aromatic units and alkyl units. This polymorph appears to be the thermodynamic stable phase. Charge carrier mobility measurements indicate an electron mobility of 4*10−6 cm2 V−1 s−1 for this phase.

Sensitized triplet–triplet annihilation based photon up-conversion (TTA-UC) greatly improves the scope and applicability of fluorescence bioimaging by enabling anti-Stokes detection at low powers, thus eliminating the background autofluorescence and limiting the potential damage of the living tissues. Here the authors present a facile, one-step protocol to prepare dual dye-doped, TTA-UC active nanomicelles starting from the commercially available surfactant Kolliphor EL, a component of several FDA approved preparations. These nanosized micelles show an unprecedented up-conversion yield of 6.5% under 0.1 W cm−2 excitation intensity in an aqueous, nondeaerated dispersion. The supramolecular architecture obtained preserves the embedded dyes from oxygen quenching, allowing satisfactory anti-Stokes fluorescence imaging of 3T3 cells. This is the first example of efficient multicomponent up-converters prepared using highly biocompatible materials approved by the international authority, paving the way for the development of new complex and multifunctional materials for advanced theranostics.

The Suzuki-Miyaura cross-coupling reaction of 4,7-dibromo-5,6-difluoro-2,1,3-benzothiadiazole with different arylboronic acids can be efficiently carried out in water and under air by means of micellar coupling. The careful tuning of reaction conditions enables preparation of symmetrically and unsymmetrically substituted derivatives. The moderate to good yields obtained, along with the wide variety of available substitution patterns, makes this sustainable methodology very useful for the preparation of building blocks for luminescent optoelectronic materials.

Planar luminescent solar concentrators are slabs of high optical quality materials doped with luminophores. Such devices enable the collection of solar light over a large area, followed by concentrated emission at the slab edges due to total internal reflection. The luminophore plays a central role as it is responsible for light absorption over the largest possible fraction of the solar spectrum and efficient emission. We show how the latent pigment approach makes it possible to prepare bulk-polymerized single-layer luminescent solar concentrators doped with the high performance pigments quinacridone and perylenediimide. The process is advantageous in terms of overall synthetic efficiency for both quinacridone and perylendiimide. In the former case a sizeable improvement in photostability is also demonstrated.

Recently, oxygen-equilibrated water solutions of Kolliphor EL, a well-known surfactant, have been seen to form nanomicelles with oxygen-free cores. This has prompted the successful testing of the core environment as a green medium for palladium-catalyzed Suzuki–Miyaura cross couplings. The versatility of these conditions is endorsed by several examples, including the synthesis of relevant molecular semiconductors. The reaction medium can also be recycled, opening the way for an extremely easy and green chemistry compliant methodology.

An alternating naphthalene dianhydride bithiophene copolymer (PNDAT2) is prepared by a combined direct arylation polycondensation and the latent pigment approach. PNDAT2 is the first reported example of an alternating conjugated polymer containing naphthalene dianhydride, the oxo-analogue of naphthalene diimide often used in electron-acceptor conjugated polymers. PNDAT2 is resistant to organic solvents and can be generated directly as film by thermal treatment of the soluble tetraester precursor PNTET2. PNDAT2 is characterized by a LUMO level of -3.9 eV, similar to that of established naphthalene diimide containing soluble copolymers. This route to insoluble electron acceptor copolymers by thermal cleavage of soluble precursors is an alternative to classical cross-linking or orthogonal processing strategies.

We examined the associations of measured anthropometric factors, including general and central adiposity and height, with ovarian cancer risk. We also investigated these associations by menopausal status and for specific histological subtypes. Among 226,798 women in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, there were 611 incident cases of primary, malignant, epithelial ovarian cancer diagnosed during a mean 8.9 years of follow-up. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (as), adjusted for potential confounders. Compared to women with body mass index (BMI) < 25 kg/m(2), obesity (BMI >= 30 kg/m(2)) was associated with excess ovarian cancer risk for all women combined (HR = 1.33, 95% Cl = 1.05-1.68; p(trend) = 0.02) and postmenopausal women (HR = 1.59, 95% Cl = 1.20-2.10; p(trend) = 0.001), but the association was weaker for premenopausal women (HR = 1.16, 95% Cl = 0.65-2.06; p(trend) = 0.65). Neither height or weight gain, nor BMI-adjusted measures of fat distribution assessed by waist circumference, waist-hip ratio (WHR) or hip circumference were associated with overall risk. WHR was related to increased risk of mucinous tumors (BMI-adjusted HR per 0.05 unit increment = 1.17, 95% Cl = 1.00-1.38). For all women combined, no other significant associations with risk were observed for specific histological subtypes. This large, prospective study provides evidence that obesity is an important modifiable risk factor for epithelial ovarian cancer, particularly among postmenopausal women.