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Deep Eutectic Solvents
Published in Papu Kumar Naik, Nikhil Kumar, Nabendu Paul, Tamal Banerjee, Deep Eutectic Solvents in Liquid–Liquid Extraction, 2023
Papu Kumar Naik, Nikhil Kumar, Nabendu Paul, Tamal Banerjee
Although DES components can be non-toxic and of a low environmental effect, the mixes of these components are not always “green” or nontoxic. The DESs have specific features that neither component has. Methyltriphenylphosphonium bromide and tetrabutylammonium bromide having slightly acute oral, skin, and inhalation toxicity. In the field of green chemistry, DESs are the most promising findings of the last several years. DES not only makes the design of safe processes possible but also allows straightforward access over the current solvent to new substances and materials. Clerk et al. [67] studied the criteria for green solvents in terms of life cycle assessment on the basis of their solvency, ease of use, reusability, health and safety, environmental impact, and economic cost that is best suited for a DES. In recent years, research on solvents has increased dramatically because of the intriguing features of DES, namely, its minimal ecological imprint and its appealing pricing. The outcome will be improved in the near future in new (not present) laboratory and industrial applications. Figure 1.4 shows the various properties of DES.
Anion-templated silver nanoclusters: precise synthesis and geometric structure
Published in Science and Technology of Advanced Materials, 2023
Yusuke Horita, Mai Ishimi, Yuichi Negishi
There are numerous reports on X@Ag8 NCs with a diverse range of central anions, including fluoride ions (F–), Cl–, and bromide ions (Br–). All these X@Ag8 NCs have been synthesized by Liu and colleagues. They reported the syntheses of 2 (F@Ag8a), 3 (F@Ag8b), 4 (Cl@Ag8a), 5 (Cl@Ag8b), 6 (Cl@Ag8c), 7 (Cl@Ag8d), 8 (Cl@Ag8e), 9 (Br@Ag8a), 10 (Br@Ag8b), 11 (Br@Ag8c), and 12 (Br@Ag8d) from 2004 to 2014 [131–133]. All of these X@Ag8 NCs were synthesized using the stirring method. For the precursors of each X, tetrabutylammonium fluoride (Bu4NF), tetrabutylammonium chloride (Bu4NCl), tetrabutylammonium bromide (Bu4NBr), benzyltriethylammonium chloride ((PhCH2)Et3NCl), or tetraphenylphosphonium bromide (PPh4Br) were used, and the central X anion is formed by their dissociation in the reaction process.
Investigation of surface adsorption and thermodynamic properties of 1-tetradecyl-3-methylimidazolium bromide in the absence and presence of tetrabutylammonium bromide in aqueous medium
Published in Journal of Dispersion Science and Technology, 2022
Harsh Kumar, Gagandeep Kaur, Shweta Sharma
1-Methylimidazole (>99%) was purchased from HIMEDIA Laboratories Pvt. Ltd. 1-Bromotetradecane (>97%) and hexane (>96%) were purchased from TCI Pvt. Ltd. Acetonitrile (>99.5%) was procured from LOBA Chemie Pvt. Ltd., Mumbai, India. Ionic liquid 1-tetradecyl-3-methylimidazolium bromide [C14mim][Br] used in this study was synthesized in the lab using these chemicals. Tetrabutylammonium bromide (>99%) was taken from Spectrochem Pvt. Ltd., Mumbai, India. The details of all the chemicals along with their source, CAS number, purification method, and mass fraction purity are given in Table 1. The chemical structures of 1-tetradecyl-3-methylimidazolium bromide [C14mim][Br] and tetrabutylammonium bromide (C4H9)4NBr are shown in Figure 1.
1,3,5-Trithianes and sulfur monochloride/sodium sulfide: an alternative route to 3,5-disubstituted 1,2,4-trithiolanes
Published in Journal of Sulfur Chemistry, 2020
Damiano Tanini, Francesca Trapani, Antonella Capperucci
Subsequently, 3a was reacted in DMF at ambient temperature with hydrate sodium sulfide (Scheme 4), which is used in the reaction with halides to form symmetrical disulfides [45], and indeed the trithiolane 5a was isolated, even if in moderate yield (22%), together with other sulfurated products, amongst which the 1,2,3,5-tetrathiane 6a was the major compound. Under these conditions the parent 1,1’-bis(mercapto)-dialkyl sulfide intermediate 4 was not isolated, being quickly oxidized to provide a direct access to 5a from 3a. In order to increase the yield of 5a the reaction was carried out in the presence of TBAB (tetrabutylammonium bromide) as phase transfer catalyst, but no considerable increase in yield was observed. On the contrary, when the reaction was performed at lower temperature (−10°C) the trithiolane 5a was achieved in higher yield (67%) as equimolar mixture of stereoisomers, and tetrathiane 6a was observed as minor compound (<5%) (Scheme 4). The reaction was also efficient with differently substituted trithianes, leading to variously 3,5-disubstituted 1,2,4-trithiolanes 5b–d under mild conditions (Scheme 4).