An efficient and simple method for synthesizing all-conjugated diblock copolymers is reported, using the Stille polycondensation of A–A (dithienosilole) and B–B (diketopyrrolopyrrole) monomers with a ...macro end-capping agent P3HT. Diblock and triblock copolymers were produced with a molar composition that was tuned via the macromonomer molar mass and feed ratio. The molar mass and topology of the macromolecules obtained are discussed on the basis of the Carothers equation, conversion, and monomer ratio. Spectrophotometry and cyclic voltammetry were used to highlight the complementarity of block absorption and the donor–acceptor nature of copolymers. Finally, integration in solar cells has been successfully performed with efficiencies reaching 2%. Performances of the devices were molar composition dependent and revealed that the performance enhancement provided by low-band-gap block absorption was balanced by the copolymer nanostructuration that shrinks the charge collection at electrodes.
Fossil fuels still need to meet the growing demand of global economic development, yet they are often considered as one of the main sources of the CO2 release in the atmosphere. CO2, which is the ...primary greenhouse gas (GHG), is periodically exchanged among the land surface, ocean, and atmosphere where various creatures absorb and produce it daily. However, the balanced processes of producing and consuming the CO2 by nature are unfortunately faced by the anthropogenic release of CO2. Decreasing the emissions of these greenhouse gases is becoming more urgent. Therefore, carbon sequestration and storage (CSS) of CO2, its utilization in oil recovery, as well as its conversion into fuels and chemicals emerge as active options and potential strategies to mitigate CO2 emissions and climate change, energy crises, and challenges in the storage of energy.
Sustainable development and alternative energy constituted urgent needs in the last decade. Renewable chemicals, energy and bio-resource use became challenging topics in the sustainable, renewable ...and green sciences. This encourages and turns primordial needs the works in certain fields as developing of new and green catalysts for chemical transformations, in the domains of energy, environmental, pharmaceutical, agro-alimentary and cosmetically applications; evaluation of bio-resources compounds largely available for many applications in energy or as additives to fuels and other applications, reduction and conversion of greenhouse gas as well as developing new synthesis routes by avoiding the use of toxic and environmentally damage materials. In this book, the recent sustainable and green process is presented in three sections: "Greenhouse Gas Conversion Efficiency in Microwave", "Biomass Green Process" and "Green Synthesis and Catalysis".
Organocatalysis has recently attracted enormous attention as green and sustainable catalysis. It was realized as a fundamental field providing wide families of catalysts for important organic ...transformations. It will certainly develop in the future. Given the diversity of accessible transformations, metal-catalyzed reactions have become major tools in organic synthesis that will undoubtedly continue to have an important impact in the future. Alternatively, over the last years, a metal-free approach such as organocatalysis has reached a level of faithfulness, allowing researchers to discover new catalytic systems based on engagement of new or early-prepared organic molecules as organocatalysts. Organocatalysis meets green chemistry principles, especially the reduction of toxicity and chemical accidents, the biodegradability, and the use of benign and friendlier reaction media and conditions.
Ideally, a sustainable chemical synthesis should involve the use of non‐toxic solvents and reactants, easy separations and purification by energy‐efficient processes. In this context, reconsidering ...the synthesis of widely used drugs is especially timely and should allow important benefits to be obtained in terms of environmental impact. Sulfonamides are pertinent as their synthesis generally requires the use of toxic and/or hard‐to‐remove solvents such as dichloromethane, DMF and DMSO. In addition, toxic and highly reactive sulfur‐containing sources such as sulfonyl chloride are often involved and coupled with amines. Moreover, the latter may exhibit some toxicity and are generally difficult to purify. Herein, we disclose the unprecedented and sustainable synthesis of sulfonamides by using sodium sulfinate as a commercial and stable sulfur source and nitroarenes as the nitrogen‐containing reactant. In addition, under the optimized conditions only water is used as a “green” solvent and the products are collected by simple filtration.
A green, sustainable and chemoselective synthesis of sulfonamides using sodium sulfinate as a commercial and stable sulfur source and nitroarenes as the nitrogen‐containing reactant is described. The optimized conditions use water as solvent and the pure products are collected by simple filtration. The method is easily scalable and protecting‐group‐free because of the high functional tolerance.
The domain of catalytic hydrogenation continues to grow fast, reflecting the wide range of chemical applications that can be enhanced by the easy use of molecular hydrogen. The advances in ...characterization techniques and their application have improved our understanding of the catalytic processes and mechanisms occurring in both homogeneous and heterogeneous catalysis. The aim of this volume, although not exhaustive, is to provide a general overview of new progress of the hydrogenation reactions. This volume comprises a series of various contributions, as reviews or original articles, treating heterogeneously and homogeneously catalyzed hydrogenation reactions. It is composed of three parts: hydrogenation reactions in fine organic chemistry, hydrogenation reactions in environmental chemistry and renewable energy, and special topics in hydrogenation.
Boron chemistry has evolved to become one of the most diverse and applied fields in organic synthesis and catalysis. Various valuable reactions such as hydroborylations and Suzuki–Miyaura ...cross-couplings (SMCs) are now considered as indispensable methods in the synthetic toolbox of researchers in academia and industry. The development of novel sterically- and electronically-demanding C(sp3)–Boron reagents and their subsequent metal-catalyzed cross-couplings attracts strong attention and serves in turn to expedite the wheel of innovative applications of otherwise challenging organic adducts in different fields. This review describes the significant progress in the utilization of classical and novel C(sp3)–B reagents (9-BBN and 9-MeO-9-BBN, trifluoroboronates, alkylboranes, alkylboronic acids, MIDA, etc.) as coupling partners in challenging metal-catalyzed C(sp3)–C(sp2) cross-coupling reactions, such as B-alkyl SMCs after 2001.
Two extractants, N,N′-((octylazanediyl)bis(ethane-2,1-diyl))dioctanamide (LI) and N,N′-((octylazanediyl)bis(ethane-2,1-diyl))di-2-methylheptanamide (LII), have been synthesised in two steps starting ...from diethylenetriamine and involving a peptide coupling step. The efficiency and selectivity of the extractants in dodecane/octanol (95/5 v/v) toward the extraction of uranium from sulfate media have been investigated showing that the uranium extraction from sulfuric acid is more efficient at a low H2SO4 concentrations. Slope analysis method revealed 2:1 extractant/metal ratio, which is in accordance with NMR titration as well as DFT calculations. The extractants are found to be selective toward uranium over competitive cations present in a simulated leach solution. Finally, a stripping step has been performed and given rise to a successful quantitative recovery of uranium.
•Extraction of uranium(VI) from sulfuric acidic solutions using amino-diamide as extracting system.•Detailed study of the extraction highlight a 2:1 stoichiometric ratio for the ligand:UO22+ complex.•A quantitative recovery of U(VI) is achieved by ammonium or sodium carbonate.
The Pd(TPPTS)3 complex (TPPTS is the sodium salt of tris(m-sulfophenyl)phosphine) easily ionizes allyl alcohol in water over a wide range of pH: OH− and TPPTS are released, and Pd(η3-allyl)(TPPTS)2+ ...is formed. The released TPPTS further reacts with the palladium cationic complex to reversibly produce both the allylphosphonium salt of TPPTS (allyl)Ar3P+ and Pd(TPPTS)3, the latter acting as the catalyst of the allylation of TPPTS by allyl alcohol. Primary allylic alcohols, such as butenol (trans-2-buten-1-ol), prenol (3-methyl-2-buten-1-ol), geraniol, and cinnamyl alcohol, react with Pd(TPPTS)3 to produce hydroxide ion, the corresponding hydrosoluble cationic palladium complex, and allylic phosphonium salts. At room temperature, Pd(η3-allyl)(TPPTS)2+ is stable up to pH 12, but beyond this value, palladium precipitates. The temperature has an adverse effect on the complex stability: palladium precipitates at 80 °C, even at pH 7, with the formation of a small amount of propylene. The addition of (allyl)Ar3P+ increases the stability of Pd(η3-allyl)(TPPTS)2+. Above pH 10, (allyl)Ar3P+ decomposes into OTPPTS and propylene by reaction with OH−. At lower pH, (allyl)Ar3P+ is slowly isomerized into (propenyl)Ar3P+, which further reduces its stability toward pH and temperature. These consecutive reactions of the TPPTS ligand could explain most of the catalyst instability. This study outlines the basis for a better understanding of the instability phenomenon of the catalytic system Pd(0)−TPPTS in reactions with allylic intermediates, e.g. the Tsuji−Trost reaction, and in the reaction of dienes in aqueous media in which palladium often precipitates.
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