scholarly journals Evidence for Hydrogen-Bonding in Solutions of 1-Methyl-3-ethylimidazolium Halides, as Determined by 1H, 35Cl and 127I NMR Spectroscopy, and Its Implications for Room-Temperature Halogenoaluminate(III) Ionic Liquids

1990 ◽  
Vol 1990-17 (1) ◽  
pp. 98-133
Author(s):  
Anthony G. Avent
2015 ◽  
Vol 53 (5) ◽  
pp. 369-378 ◽  
Author(s):  
Takatsugu Endo ◽  
Mamoru Imanari ◽  
Yuki Hidaka ◽  
Hiroko Seki ◽  
Keiko Nishikawa ◽  
...  

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.


2021 ◽  
Author(s):  
Yueting Xu ◽  
Yanfei Zhao ◽  
Fengtao Zhang ◽  
Yuepeng Wang ◽  
Ruipeng Li ◽  
...  

Alcoholysis of propylene oxide is achieved over azolate ionic liquids at room temperature by hydrogen-bonding catalysis, accessing glycol ethers in moderate to high yields with selectivity of >99%.


2002 ◽  
Vol 4 (5) ◽  
pp. 517-520 ◽  
Author(s):  
Ajay Aggarwal ◽  
N. Llewellyn Lancaster ◽  
Alick R. Sethi ◽  
Tom Welton

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 355
Author(s):  
Fabricio R. Bisogno ◽  
Rosario Fernández ◽  
Jose María Lassaletta ◽  
Gonzalo de de Gonzalo

Room temperature ionic liquids (RTILs) have been widely used as (co)solvents in several catalytic processes modifying, in most of the cases, the catalyst activity and/or the selectivity for the studied reactions. However, there are just a few examples of their use in hydrogen bonding organocatalysis. In this paper, we show the positive effect of a set of imidazole-based ionic liquids ([bmim]BF4 and [hmim]PF6) in the enantioselective addition of formaldehyde tert-butylhydrazone to prochiral α-keto esters catalyzed by a sugar-based chiral thiourea. Reactions performed in the presence of low percentages of RTILs led to an increase of the catalyst activity, thereby making possible to work at lower temperatures. Thus, the chiral tert-butyl azomethyl tertiary alcohols could be obtained with moderate to good conversions and higher enantioselectivities for most of the studied substrates when using up to 30 vol% of [hmim]PF6 as a cosolvent in processes performed in toluene.


2018 ◽  
Vol 9 (3) ◽  
pp. 106
Author(s):  
Jelliarko Palgunadi ◽  
Antonius Indarto ◽  
Haryo Winoto ◽  
Hoon Sik Kim

Separation or removal of propyne from propylene, generated by naptha cracking process, is one of the most important processes in petrochemical industries because ppm level of propyne contained in feed olefins can serve as catalyst poisons in the polymerization of olefins. Recently, room temperature ionic liquids (RTILs) were introduced as novel solvents for the separation of various gases and hydrocarbons. RTIL is a salt composed of unsymmetrical organic cation and organic/inorganic anion which melts at room temperature. Prior to the decision of material selection for the effective separation of propyne/propylene employing RTIL, solubility behaviors and selectivities of propyne and propylene in various RTILs were investigated. For the solubility of propyne and propylene in 1-R-3-methylimidazolium-based RTILs, solubility measurement, thermodynamic analysis, and computational calculation strongly imply that the solubility of propyne is controlled by a trade-off between a specific solute-solvent interaction (hydrogen bonding of propyne-anion) and non bonding interaction (solubility parameter). In contrast, the solubility of propylene seems to be much strongly dependent on non-bonding interaction (solubility parameter) closely related to the physical attractive forces as suggested by regular solution theory. Thus, to achieve high selectivity of propyne over propylene, a RTIL with smaller-size and stronger hydrogen bonding ability should be employed.Keywords: propyne, propylene, solubility, selectivity, ionic liquidsAbstrakPemisahan senyawa propuna dari propena, yang dihasilkan oleh proses fraksionasi nafta adalah salah satu proses yang paling penting dalam industri petrokimia. Kontaminan propuna yang terkandung dalam umpan olefin dapat menjadi racun katalis dalam proses polimerisasi olefin. Kini cairan ionik temperatur ruang (RTIL) diperkenalkan sebagai pelarut baru untuk pemisahan berbagai gas dan hidrokarbon. RTIL adalah garam yang terdiri dari kation organik dan anion organik/anorganik asimetrik yang meleleh pada suhu kamar. Pemilihan senyawa pelarut RTIL yang tepat untuk pemisahan propuna / propena akan dibahas dalam tulisan ini. Dalam proses pelarutan propuna dalam RTIL berbasis 1-R-3-metilimidazolium, pengukuran kelarutan, analisis termodinamika, dan pemodelan mengisyaratkan bahwa kelarutan propuna dikendalikan oleh kompromi antara interaksi spesifik solut-pelarut (ikatan hidrogen propuna-anion) dan interaksi tak mengikat  (parameter kelarutan). Sebaliknya, kelarutan propena sangat bergantung pada interaksi tak mengikat (parameter kelarutan) yang erat hubungannya dengan ikatan fisik seperti dipaparkan dalam teori larutan biasa (regular solution theory). Dengan demikian, untuk mencapai selektivitas tinggi terhadap propuna dibandingkan dengan propena, disarankan untuk menggunakan senyawa RTIL dengan ukuran molekul lebih kecil yang memiliki ikatan hidrogen lebih kuat.Kata Kunci: propuna, propena, kelarutan, absorpsi, cairan ionik


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