scholarly journals Antibacterial, Antifungal and Ecotoxic Effects of Ammonium and Imidazolium Ionic Liquids Synthesized in Microwaves

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5181
Author(s):  
Jana Fojtášková ◽  
Ivan Koutník ◽  
Martina Vráblová ◽  
Hana Sezimová ◽  
Milan Maxa ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Alkyl Chain ◽  
Vibrio Fischeri ◽  
Alkyl Chain Length ◽  
Conventional Heating ◽  
Microwave Assisted Synthesis ◽  
Duration Of Action ◽  
Solubility In Water ◽  
Microwave Assisted ◽  
Microwave Reactor

Ionic liquids are increasingly used for their superior properties. Four water-immiscible ionic liquids (butyltriethylammonium bis(trifluoromethylsulfonyl)imide, octyltriethylammonium bis(trifluoromethylsulfonyl)imide, dodecyltriethylammonium bis(trifluoromethylsulfonyl)imide, butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) and their water miscible precursors (bromides) were synthesized in a microwave reactor and by conventional heating. The best conditions for microwave-assisted synthesis concerning the yield and the purity of the product are proposed. The heating in the microwave reactor significantly shortened the reaction time. Biocide and ecotoxic effects of synthesized ionic liquids and their precursors were investigated. All tested compounds had at least a little effect on the growth or living of microorganisms (bacteria or mold). The precursor dodecyltriethylammonium bromide was found to be the strongest biocide, but posed a risk to the aquatic environment due to its relatively high EC50 value in the test with Vibrio fischeri. We assumed that apart from the alkyl chain length, the solubility in water, duration of action, or type of anion can influence the final biocide and ecotoxic effect.

scholarly journals New Guanidinium-based Room-temperature Ionic Liquids. Substituent and Anion Effect on Density and Solubility in Water

2010 ◽  
Vol 65 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Milen G. Bogdanov ◽  
Desislava Petkova ◽  
Stanimira Hristeva ◽  
Ivan Svinyarov ◽  
Willi Kantlehner
Keyword(s):  
Ionic Liquids ◽  
Physical Properties ◽  
Room Temperature ◽  
Alkyl Chain ◽  
Alkyl Substituent ◽  
Alkyl Chain Length ◽  
Solubility In Water ◽  
Anion Effect ◽  
Ion Exchange Reaction ◽  
As Solubility

In order to examine the influence of the alkyl chain length on some physical properties of guanidinium salts, the synthesis of a homologous series of new N″-n-alkylsubstituted N,N-diethyl-N′ ,N′- di-n-propyl-N″-n-hexyl guanidinium ionic liquids (gILs), containing chloride (Cl), tetrafluoroborate (BF4), acesulfamate (Ace), saccharinate (Sac), and tosylate (Tos) as anions, is reported. Cn-gILAce, Cn-gILSac, and Cn-gILBF4 were obtained by ion exchange reaction of the corresponding hexasubstituted guanidinium chlorides (Cn-gCl, n = 3, 4, 6, 8, 10), which were synthesized by a quaternization reaction of the pentaalkyl-substituted guanidine 3 and the corresponding alkylchloride in DMF. The tosylates gILs Cn-gTos (n = 1, 2, 4, 6, 8, 10) were synthesized by alkylation of 3 with the corresponding alkyltosylates. Some physical properties, such as solubility in water and organic solvents, refractive index and density, are considered as a function of the length of the n-alkyl substituent R and the nature of the anion

Microwave-assisted Synthesis of 1-(perfluorohexyl)-3-methylimidazolium iodide

MRS Advances ◽  
2019 ◽  
Vol 5 (27-28) ◽  
pp. 1449-1456
Author(s):  
James E. Knoop ◽  
Jeffrey R. Alston
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Reaction Times ◽  
Microwave Assisted Synthesis ◽  
Imidazolium Ionic Liquid ◽  
Alkyl Chains ◽  
Microwave Assisted ◽  
Microwave Reactor ◽  
Microwave Reaction ◽  
Crystallization Onset

ABSTRACTA perfluorinated ionic liquid, 1-(perfluorohexyl)-3-methylimidazolium iodide, was synthesized via microwave reaction and compared to a non-fluorinated analog. Typically, the synthesis of fluorinated ionic liquids involves long reaction times and multiple steps. We have demonstrated a shortened synthesis and a more straightforward procedure, by using a microwave reactor for the microwave-assisted synthesis of 1-(perfluorohexyl)-3-methylimidazolium iodide. The addition of fluorinated alkyl chains on imidazolium ionic liquid cations increases the molecular free volume of the ionic liquid which is beneficial for increasing CO2 physisorption. Computational and experimental data shows an increased CO2 solubility and capacity for fluorinated ionic liquids. The perfluoroalkyl functionalized ionic liquid is characterized using 1H and 19F NMR spectroscopy, FTIR spectroscopy, and DSC. By DSC, a crystallization onset is near -31 °C and while the onset of the melting point between -30 and -17 °C.

Microwave-assisted Synthesis of Benzoxazoles Derivatives

2020 ◽  
Vol 7 (3) ◽  
pp. 183-195
Author(s):  
Musa Özil ◽  
Emre Menteşe
Keyword(s):  
Microwave Irradiation ◽  
Reaction Medium ◽  
Pharmaceutical Chemistry ◽  
Conventional Heating ◽  
High Yield ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Optical Brighteners ◽  
Chemistry Research ◽  
Extensive Class

Background: Benzoxazole, containing a 1,3-oxazole system fused with a benzene ring, has a profound effect on medicinal chemistry research owing to its important pharmacological activities. On the other hand, the benzoxazole derivative has exhibited important properties in material science. Especially in recent years, microwave-assisted synthesis is a technique that can be used to increase diversity and quick research in modern chemistry. The utilization of microwave irradiation is beneficial for the synthesis of benzoxazole in recent years. In this focused review, we provide a metaanalysis of studies on benzoxazole in different reaction conditions, catalysts, and starting materials by microwave technique so far, which is different from conventional heating. Methods: Synthesis of different kind of benzoxazole derivatives have been carried out by microwave irradiation. The most used method to obtain benzoxazoles is the condensation of 2-aminophenol or its derivatives with aldehydes, carboxylic acids, nitriles, isocyanates, and aliphatic amines. Results: Benzoxazole system and its derivatives have exhibited a broad range of pharmacological properties. Thus, many scientists have remarked on the importance of the synthesis of different benzoxazole derivatives. Conventional heating is a relatively inefficient and slow method to convey energy in orientation to the reaction medium. However, the microwave-assisted heating technique is a more effective interior heating by straight coupling of microwave energy with the molecules. Conclusion: In this review, different studies were presented on the recent details accessible in the microwave- assisted techniques on the synthesis of the benzoxazole ring. It presents all examples of such compounds that have been reported from 1996 to the present. Benzoxazoles showed an extensive class of chemical substances not only in pharmaceutical chemistry but also in dyestuff, polymer industries, agrochemical, and optical brighteners. Thus the development of fast and efficient achievement of benzoxazoles with a diversity of substituents in high yield is getting more noteworthy. As shown in this review, microwave-assisted synthesis of benzoxazoles is a very effective and useful technique.

scholarly journals Microwave-Assisted Preparation of Luminescent Inorganic Materials: A Fast Route to Light Conversion and Storage Phosphors

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2882
Author(s):  
José Miranda de Carvalho ◽  
Cássio Cardoso Santos Pedroso ◽  
Matheus Salgado de Nichile Saula ◽  
Maria Claudia França Cunha Felinto ◽  
Hermi Felinto de Brito
Keyword(s):  
Rapid Heating ◽  
Inorganic Materials ◽  
Rapid Screening ◽  
Conventional Heating ◽  
Quantum Yields ◽  
Microwave Assisted Synthesis ◽  
Volumetric Heating ◽  
White Leds ◽  
Microwave Assisted ◽  
And Storage

Luminescent inorganic materials are used in several technological applications such as light-emitting displays, white LEDs for illumination, bioimaging, and photodynamic therapy. Usually, inorganic phosphors (e.g., complex oxides, silicates) need high temperatures and, in some cases, specific atmospheres to be formed or to obtain a homogeneous composition. Low ionic diffusion and high melting points of the precursors lead to long processing times in these solid-state syntheses with a cost in energy consumption when conventional heating methods are applied. Microwave-assisted synthesis relies on selective, volumetric heating attributed to the electromagnetic radiation interaction with the matter. The microwave heating allows for rapid heating rates and small temperature gradients yielding homogeneous, well-formed materials swiftly. Luminescent inorganic materials can benefit significantly from the microwave-assisted synthesis for high homogeneity, diverse morphology, and rapid screening of different compositions. The rapid screening allows for fast material investigation, whereas the benefits of enhanced homogeneity include improvement in the optical properties such as quantum yields and storage capacity.

Spectroscopic Study on Imidazolium-Based Ionic Liquids: Effect of Alkyl Chain Length and Anion

2012 ◽  
Vol 116 (11) ◽  
pp. 3512-3518 ◽  
Author(s):  
Enrico Binetti ◽  
Annamaria Panniello ◽  
Leonardo Triggiani ◽  
Raffaele Tommasi ◽  
Angela Agostiano ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Spectroscopic Study ◽  
Chain Length ◽  
Alkyl Chain ◽  
Alkyl Chain Length

Thermo-physical and tribological characteristics of ionic liquid-based rice bran oil as green cutting fluid

2021 ◽  
pp. 135065012110461
Author(s):  
Aswani K Singh ◽  
Varun Sharma
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Coefficient Of Friction ◽  
Rice Bran ◽  
Alkyl Chain ◽  
Rice Bran Oil ◽  
Alkyl Chain Length ◽  
Cutting Fluid ◽  
Cutting Fluids ◽  
Base Oil

During machining, the cutting fluids play an essential role in cooling and lubrication. In order to reduce the friction forces, the excessive amount of the cutting fluids are generally used. This, in turn, leads to wastage of the cutting fluids which results in a serious impact on the environment, health and cost of production. Therefore, the judicious use of lubricants is the foremost concern in the manufacturing industry. In order to mitigate these drawbacks, various alternatives have been developed in the last decade. In the present paper, ionic liquids have been proved as favourable sustainable alternative additives in the base oil. The effect of alkyl chain length of ionic liquids with base oil on the thermo-physical and tribological characteristics of cutting fluids including viscosity, wettability, anticorrosion behaviour, thermal stability, and coefficient of friction have been analysed. In the present study, pyrrolidinium and hexafluoro-phosphate (PF6) have been used as cation and anion, respectively, with rice bran oil as base oil. The five different ionic liquids have been dispersed in base oil by 1.0 wt%. It has been found that longer alkyl chain length showed the favourable results as compared to the shorter one. Results indicated that ionic liquid based cutting fluid attained ample enhanced thermophysical and tribological properties as compared to the neat rice bran oil. There has been 5.08% and 4.29% improvement in viscosity and thermal conductivity for IL4 + RBO in comparison to neat RBO. In addition, the wettability, coefficient of friction, and wear volume have been reduced by 20.34%, 53.79% and 57.87% correspondingly.

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