DFT study of structures and hydrogen bonds of imidazolium based halogen-free boron containing dicationic ionic liquids

2018 ◽  
Vol 256 ◽  
pp. 330-343 ◽  
Author(s):  
Seyed Morteza Alavi ◽  
Saied Yeganegi
Friction ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 344-355
Author(s):  
Qiangliang Yu ◽  
Chaoyang Zhang ◽  
Rui Dong ◽  
Yijun Shi ◽  
Yurong Wang ◽  
...  

AbstractA series of new halogen-free dicationic ionic liquids (ILs) with different alkyl chain lengths were prepared, and the relationship between the alkyl chain length, physicochemical and tribological properties of ILs, and their role as neat lubricant for steel-steel friction pairs, was investigated. Evaluation of stability during hydrolysis and copper strip corrosion test results show that synthetic ILs are stable and not corrosive to metal contacts, due to the halogen-free anions. The friction and wear test results indicate that ILs with long alkyl chains have excellent friction-reducing and anti-wear properties, especially at high temperatures. Based on the surface three-dimensional (3D) profiles, electrical contact resistance, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and the X-ray photoelectron spectrometry (XPS) analysis of the worn surfaces of steel discs, we can conclude that the efficiency of ILs is due to the formation of high quality tribofilms that consist of both tribochemical reaction and ordered absorption films.


2020 ◽  
Vol 17 (4) ◽  
pp. 450-464
Author(s):  
Mohammad Javaherian ◽  
Seyyed Jafar Saghanezhad

Dicationic ionic liquids are an emerging group of Ionic Liquids (ILs) that are currently receiving much attention as green reaction media and catalysts. Because of a great number of possible combinations of cations and anions, the physical and chemical properties of dicationic ionic liquids are more tunable and broader than monocationic ILs. Therefore, their unique properties have made them the target of many applied and fundamental researches. Actually, dicationic ionic liquids are more effective and rather fascinating than traditional monocationic ILs. So, due to greater versatility and diversity, their applications in organic synthesis have been extensively grown. In this review, we have focused on the synthesis, characterization and applications of dicationic ionic liquids, especially, in organic synthesis.


2021 ◽  
Vol 125 (5) ◽  
pp. 1416-1428
Author(s):  
Jing Ma ◽  
Yutong Wang ◽  
Xueqing Yang ◽  
Mingxuan Zhu ◽  
Baohe Wang

2021 ◽  
pp. 116251
Author(s):  
M.A. Olea-Amezcua ◽  
J.E. Castellanos-Águila ◽  
H. HernÁndez-Cocoletzi ◽  
E. Ferreira ◽  
M. Trejo-Durán ◽  
...  

2021 ◽  
Vol 14 (5) ◽  
pp. 103123
Author(s):  
C.E. El shafiee ◽  
R.A. El-Nagar ◽  
M.I. Nessim ◽  
M.M.H. Khalil ◽  
M.E. Shaban ◽  
...  

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Malgorzata M. Jaworska ◽  
Andrzej Górak ◽  
Joanna Zdunek

Chitin cannot be dissolved in conventional solvents due to the strong inter- and intrasheet network of hydrogen bonds and the large number of crystalline regions. Some ionic liquids (ILs) have been suggested in the literature as possible solvents for chitin. Seven of them, all having an ethyl group as substituent in the cationic ring, have been tested in this work: [Emim][Cl], [Emim][Br], [Emim][I], [Emim][OAc], [Emim][Lact], [Epyr][I], and [EMS][BFSI]. Chitin was insoluble in [EMS][BFSI] while for all other ILs solubility was limited due to high viscosity of solutions and equilibria have not been reached. Changes in physical structure, particle size distribution, and crystallinity of recovered chitin depended on ionic liquid used. Increase in porosity was observed for chitin treated with [Emim][Cl], [Emim][I], [Emim][Br], and [Emim][Lact]; changes in particle size distribution were observed for [Emim][AcOH] and [EMS][BFSI]; increase in crystallinity was noticed for chitin treated with [Epyr][I] while decrease in crystallinity for [Emim][I] was noticed. All tested ionic liquids were reused four times and changes in FTIR spectra could be observed for each IL.


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