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Interlocked Systems in Catalysis and Switching
Published in Jubaraj Bikash Baruah, Principles and Advances in Supramolecular Catalysis, 2019
The construction of a rotaxane through catalytic reactions based on an active site on a cyclic macrocycle is illustrated in Figure 4.2. A cyclic derivative of 1,2-cyclohexyldiamine 4.2a forms a copper (I) complex 4.2b upon reaction with copper iodide. This complex, with a catalytic amount of cesium carbonate, reacts with an amide derivative, thereby forms the complex 4.2c. This copper(I) complex 4.2c has a deprotonated amide coordinated to the copper ion. During the course of this reaction, cesium bicarbonate is formed from cesium carbonate. The amido-copper (I) complex 4.2c undergoes an oxidative addition reaction with iodo-derivative forming a reaction intermediate 4.2d. This intermediate is ready for the C─N bond formation reaction, and the reductive elimination forms the desired rotaxane 4.2e and releases copper (I) iodide for the next catalytic cycle. Copper (I) acetate can also be used instead of copper (I) iodide.
What is iodine?
Published in Tatsuo Kaiho, Iodine Made Simple, 2017
In the copper method, a reaction is created by placing cuprous sulfate and ferrous sulfate in a brine. Copper iodide is allowed to precipitate, then any sediment is filtered and washed out in order to obtain crude copper iodide with approximately 50% iodine concentration. Next, after drying, the crude copper iodide is heated and oxidative decomposition is carried out to obtain iodine. In the activated carbon absorption method, sulfuric acid is added to the brine and after adjusting pH value to 2–4, sodium nitrite is added as an oxidant to liberate the iodine. Activated carbon, at approximately 7 times the quantity of free iodine, is added to absorb the iodine. Next, sodium hydroxide and sodium carbonate are added to the activated carbon with the absorbed iodine and heated, which is subsequently eluted as sodium iodide. This solution is concentrated in an iron pot, then acidified by sulfuric acid and oxidized with chlorine, resulting in the precipitation of iodine.
Macrocyclic Receptors Synthesis, History, Binding Mechanism: An Update on Current Status
Published in Satish Kumar, Priya Ranjan Sahoo, Violet Rajeshwari Macwan, Jaspreet Kaur, Mukesh, Rachana Sahney, Macrocyclic Receptors for Environmental and Biosensing Applications, 2022
Satish Kumar, Priya Ranjan Sahoo, Violet Rajeshwari Macwan, Jaspreet Kaur, Mukesh, Rachana Sahney
In 2015, Hernandez-Alonso et al. published an improved protocol for the synthesis of carboxylic acid-based water-soluble receptor 46 (Scheme 26) (Hernandez-Alonso et al. 2015). Condensation of butynyl phenyl ketone with pyrrole in acidic medium (methane sulfonic acid) produced cyclic product. Subsequent reaction with azide in the presence of copper iodide and triethyl amine in DMSO resulted in the desired tetracarboxylic acid appended calix[4] pyrrole receptor 46 in 66% yield. Judiciously, the upper rim of receptor 46 is unblocked, making it suitable for further functionalization. Surprisingly, receptor 46 formed complexes with a variety of pyridyl N-oxide guest molecules in an aqueous medium through H-bonding.
Antibacterial agents applied as antivirals in textile-based PPE: a narrative review
Published in The Journal of The Textile Institute, 2022
Zulfiqar Ali Raza, Muhammad Taqi, Muhammad Rizwan Tariq
The hence prepared fabrics exhibits good antibacterial properties which could also be extended for the characterization of antiviral activity and then in the preparation of textile-based PPE. The textile-based coatings of metal oxides might also be used both as antibacterial and antiviral barriers. The copper oxide (CuO) and TiO2 express good antiviral activities against HIV and H1N1 viruses etc. Likewise, copper iodide (CuI) had been used as an antiviral agent along with a good outlook on the treated fabric. The NPs of CuI could also be a good choice to apply on the textile-based PPE and other protective clothes (Fujimori et al., 2012). A schematic presentation of possible interaction of COVID-19 with both controlled and antiviral treated PPE’s fabrics is shown in Figure 5.
Influence of multifluorophenyloxy terminus on the mesomorphism of the alkoxy and alkyl cyanobiphenyl compounds in search of new ambient nematic liquid crystals and mixtures
Published in Liquid Crystals, 2021
Kunlun Wang, Mohammad S. Rahman, Tibor Szilvási, Jake I. Gold, Nanqi Bao, Huaizhe Yu, Nicholas L. Abbott, Manos Mavrikakis, Robert J. Twieg
Commercial-grade solvents were used without further purification. PdCl2 was bought from Pressure Chemical (Pittsburgh, PA). Palladium on carbon (5%), diisopropylamine, ether and copper iodide were purchased from Acros. The precursor 4ʹ-cyano-4-iodobiphenyl was prepared using a literature method [23]. The poisoned catalyst required for preferential alkyne reduction in the presence of a nitrile was also prepared using a literature method [24]. Triphenylphosphine and ethylenediamine were bought from Sigma-Aldrich. The pentafluoropyridine, pentafluorobenzonitrile, hexafluorobenzene, bromopentafluorobenzene chloropentafluorobenzene and pentafluorostyrene were purchased from Oakwood Products (Columbia, SC). The decafluorobiphenyl and pentafluorobenzene were purchased from Matrix Scientific (Columbia, SC). The terminal hydroxyacetylenes were purchased from GFS Organic Chemicals (Columbus, OH). The compressed hydrogen was bought from Linde Gas. Sythesis of all precursors can be accessed in supplemental information. The products were purified by column chromatography using silica gel (60–120 mesh) and/or by recrystallisation from analytical grade solvents.
New room temperature nematogens by cyano tail termination of alkoxy and alkylcyanobiphenyls and their anchoring behavior on metal salt-decorated surface
Published in Liquid Crystals, 2020
Kunlun Wang, Tibor Szilvási, Jake Gold, Huaizhe Yu, Nanqi Bao, Prabin Rai, Manos Mavrikakis, Nicholas L. Abbott, Robert J. Twieg
Commercial-grade solvents were used without further purification. PdCl2 was purchased from Pressure Chemical (Pittsburgh, PA). Palladium on carbon (5%), diisopropylamine, ether and copper iodide were purchased from Acros. The precursor 4ʹ-cyano-4-iodobiphenyl was prepared using a literature method [23]. The 4ʹ’-hydroxy-1,1ʹ:4ʹ,1ʹ’-terphenyl-4-carbonitrile was prepared by Suzuki coupling reaction of 1-bromo-4-hydroxybiphenyl and 4-cyanophenylboronic acid [24]. Triphenylphosphine and ethylenediamine were purchased from Sigma-Aldrich. The 4-bromobutyronitrile and 6-bromohexanenitrile were purchased from Alfa Aesar (Ward Hill, MA). The 5-bromovaleronitrile and 7-bromoheptanenitrile were purchased from Matrix Scientific (Columbia, SC). The hexafluorobenzene was purchased from Oakwood Products (Columbia, SC). Sodium cyanide was purchased from Mallinckrodt Chemical Works (New York, NY). The terminal hydroxyacetylenes were purchased from GFS Organic Chemicals (Columbus, OH). The compressed hydrogen was bought from Linde Gas. The products were purified by column chromatography using silica gel (60–120 mesh) and/or by recrystallisation from analytical grade solvents.