Challenges in chemical synthesis at the border of solution-based and solid-state chemistry—Synthesis and structure of [CH3CH2Ge9{Si(SiMe3)3}]2−
We present a synthetic method for a stepwise ligand exchange reaction at a Zintl ion. Herein, we functionalized the [Ge9{Si(SiMe3)3}2]2− cluster with an ethyl group by a reaction with bromoethane. The obtained anion [CH3CH2Ge9{Si(SiMe3)3}2]− was characterized by NMR spectroscopy and mass spectrometry. After addition of 2,2,2-crypt an abstraction of one silyl ligand was observed resulting in the crystallization of [K(2,2,2-crypt)]2[CH3CH2Ge9{Si(SiMe3)3}] representing the first monosilylated Ge9 Zintl cluster, which carries an additional ethyl group. The latter compound was characterized by single crystal X-ray crystallo...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Macroscopic methods: Magnetic, optical, and calorimetric techniques
In this study, we will focus on the basis and the evolution of three critical macroscopic tools, i.e. the optical, magnetic, and calorimetric characterization methods. (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Materials from binary tetrahedral main group element units
Publication date: Available online 23 May 2018Source: Comptes Rendus ChimieAuthor(s): Stefanie DehnenAbstractSynthetic approaches to new materials are as various as the nature of the materials themselves. Here, we report on one synthetic concept that was used during the recent past to address a variety of different families of compounds from superionic conductors and supersphere cages for molecular trapping to new white-light generators and reactive multimetallic clusters. The use of small binary molecules comprising atoms of two main group elements is the base of all of the presented methodologies, which lead to the named...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Selective multistage extraction process of biomolecules from vine shoots by a combination of biological, chemical, and physical treatments
Publication date: June 2018Source: Comptes Rendus Chimie, Volume 21, Issue 6Author(s): Hiba N. Rajha, Sally El Kantar, Charbel Afif, Nadia Boussetta, Nicolas Louka, Richard G. Maroun, Eugene VorobievAbstractA multistep extraction process was proposed to recover polyphenols, reducing sugars, and soluble lignin from vine shoots. A physical pretreatment by high voltage electrical discharges (HVED) was followed by an enzymatic hydrolysis and a final delignification step by alkaline hydrolysis. HVED before enzymatic hydrolysis enhanced the extraction of polyphenols (+72%), reducing sugars (+43%), and soluble lignin (+104%) as c...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Editorial Board - French
Publication date: June 2018Source: Comptes Rendus Chimie, Volume 21, Issue 6Author(s): (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Sommaire / Contents
Publication date: June 2018Source: Comptes Rendus Chimie, Volume 21, Issue 6Author(s): (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Workshop on alternative solvents for synthesis, extraction, purification, and formulation (WAS 2017)
Publication date: June 2018Source: Comptes Rendus Chimie, Volume 21, Issue 6Author(s): Bruno Andrioletti, Ludivine Jean-Gérard, Anne-Sylvie Fabiano-Tixier, Farid Chemat (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Controlled pinewood fractionation with supercritical ethanol: A prerequisite toward pinewood conversion into chemicals and biofuels
In this study, the conversion of each pinewood component was determined by the analysis of solid residues to quantify cellulose, hemicellulose, lignin, and char contents. It is shown that, by tuning the temperature, hemicellulose and lignin are already transformed in subcritical ethanol conditions, lignin being more reactive than hemicellulose. In contrast, native wood cellulose is recalcitrant to liquefaction in SC ethanol near the critical point (Tc = 241 °C and Pc = 61 bar), but 20% of native wood cellulose is converted in SC ethanol at 280 °C. Besides, the severity of the conditions, in terms of temperature an...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Wheat straw lignin extraction with bio-based solvents using enabling technologies
Publication date: June 2018Source: Comptes Rendus Chimie, Volume 21, Issue 6Author(s): Emanuela Calcio Gaudino, Silvia Tabasso, Giorgio Grillo, Giancarlo Cravotto, Thomas Dreyer, Gerhard Schories, Sven Altenberg, Lilija Jashina, Galina TelyshevaAbstractTwo bio-based solvents, natural deep eutectic solvents (NaDESs) and γ-valerolactone (GVL), have been used under microwave (MW), and ultrasound (US) irradiation to design an efficient and sustainable process for wheat straw delignification and have been compared with the traditional alkali procedure. Best delignification (45%) was achieved with a three-component NaDES (lacti...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Potentialities of using liquefied gases as alternative solvents to substitute hexane for the extraction of aromas from fresh and dry natural products
Publication date: June 2018Source: Comptes Rendus Chimie, Volume 21, Issue 6Author(s): Vincent Rapinel, Cyrille Santerre, Farnaz Hanaei, Justine Belay, Nadine Vallet, Njara Rakotomanomana, Alain Vallageas, Farid ChematAbstractThe potential of liquefied gases, n-butane, dimethyl ether, and HFO-1234ze as effective and green alternative solvents to substitute hexane has been evaluated for the extraction of aromatic compounds from dry lavender flowers (Lavandula angustifolia Mill.) and fresh orange peels (Citrus sinensis (L.) Osbeck). The performance of these liquefied gases as solvents has been evaluated in terms of yield, ol...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Editorial Board - English
Publication date: June 2018Source: Comptes Rendus Chimie, Volume 21, Issue 6Author(s): (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Some aspects of green solvents
Publication date: June 2018Source: Comptes Rendus Chimie, Volume 21, Issue 6Author(s): Katharina Häckl, Werner KunzAbstractChemical solvents constitute around 80% of the total volume of chemicals used in many important chemical processes, especially fine chemical manufacturing. Unfortunately, these solvents are often volatile organic compounds from petroleum resource bearing several health and environmental risks. Numerous researchers take these two aspects as a reason to search for novel green solvents to replace the conventional ones. As a consequence, there are an increasing number of publications dealing with green so...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Parameter optimization in microwave-assisted distillation of frankincense essential oil
In conclusion, MAD is a promising technology for producing olibanum oil with new qualitative attributes. (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Computer-aided product design of alternative solvents based on phase equilibrium synergism in mixtures
Publication date: June 2018Source: Comptes Rendus Chimie, Volume 21, Issue 6Author(s): Ivonne Rodriguez-Donis, Sophie Thiebaud-Roux, Sophie Lavoine, Vincent GerbaudAbstractA systematic methodology is proposed to find binary azeotropic mixtures as new alternative solvents for the extraction process of volatile aroma molecules widely used in perfume and cosmetic industries. We investigated the use of the reverse engineering approach with computer-aided product design (CAPD) instead of the traditional “trial and error” approach. First, the design problem is defined from the real functionalities of the classical solvents. ...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Green solvents from ionic liquids and deep eutectic solvents to natural deep eutectic solvents
This article contains a review of the applications of NADESs as extraction solvents, reaction media, and preservative, providing also a perspective of their future. (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
