scholarly journals Structural Features and Properties of Metal Complexes in Ionic Liquids: Application in Alkylation Reactions

Author(s):  
Cinzia Chiappe ◽  
Tiziana Ghilardi ◽  
Christian Silvio Pomelli
Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2479 ◽  
Author(s):  
Artyom V. Belesov ◽  
Anton V. Ladesov ◽  
Ilya I. Pikovskoi ◽  
Anna V. Faleva ◽  
Dmitry S. Kosyakov

Ionic liquids (ILs) based on 1-butyl-3-methylimidazolium (bmim) cation have proved to be promising solvents for the fractionation of plant biomass with the production of cellulose and lignin. This study deals with the characterization of lignins isolated from coniferous (spruce) wood using [bmim]OAc and [bmim]MeSO4 ionic liquids and their binary mixtures with DMSO (80:20). Molecular weight distributions, functional composition, and structural features of IL lignins were studied by size-exclusion chromatography, NMR spectroscopy (1D and 2D) and atmospheric pressure photoionization high-resolution mass spectrometry. It was shown that the interaction of ILs with lignin leads to significant chemical changes in the biopolymer; a decrease in the degree of polymerization and in the content of free phenolic hydroxyl groups due to alkylation, the disappearance (in the case of [bmim]OAc) of carbonyl groups and a significant destruction of β-O-4 bonds. The chemical reactions between lignin and 1-butyl-3-methylidazolium cation with covalent binding of ionic liquids or products of their decomposition is evidenced by the presence of a large number of nitrogen-containing oligomers in IL lignins.


2019 ◽  
Vol 43 (1) ◽  
pp. 20-23 ◽  
Author(s):  
Deepak Chand ◽  
Muhammad Qamar Farooq ◽  
Arjun K. Pathak ◽  
Jingzhe Li ◽  
Emily A. Smith ◽  
...  

Nickel(ii), cobalt(ii) and manganese(ii) N-alkylimidazole bis[(trifluoromethyl)sulfonyl]imide magnetic ionic liquids were synthesized from their chloride intermediates and their physicochemical properties studied.


Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 13
Author(s):  
Khairulazhar Jumbri ◽  
Mohd Azlan Kassim ◽  
Normawati M. Yunus ◽  
Mohd Basyaruddin Abdul Rahman ◽  
Haslina Ahmad ◽  
...  

This work presents a molecular level investigation on the nature and mode of binding between imidazolium-based ionic liquids (ILs) ([Cnbim]Br where n = 2, 4, 6) with calf thymus DNA. This investigation offers valuable insight into the mechanisms of interactions that can affect the structural features of DNA and possibly cause the alteration or inhibition of DNA function. To expedite analysis, the study resorted to using molecular docking and COnductor like Screening MOdel for Real Solvents (COSMO-RS) in conjunction with fluorescence spectroscopic data for confirmation and validation of computational results. Both the fluorescence and docking studies consistently revealed a weak interaction between the two molecules, which corresponded to the binding energy of a stable docking conformation in the range of −5.19 to −7.75 kcal mol−1. As predicted, the rod-like structure of imidazolium-based ILs prefers to bind to the double-helix DNA through a minor groove. Interestingly, the occurrence of T-shape π-π stacking was observed between the amine group in adenine that faces the aromatic ring of imidazole. In addition, data of COSMO-RS for the interaction of individual nucleic acid bases to imidazolium-based ILs affirmed that ILs showed a propensity to bind to different bases, the highest being guanine followed by cytosine, thymine, uracil, and adenine.


2019 ◽  
Vol 91 (4) ◽  
pp. 563-573 ◽  
Author(s):  
Marta Gozzi ◽  
Benedikt Schwarze ◽  
Evamarie Hey-Hawkins

Abstract Today, medicinal chemistry is still clearly dominated by organic chemistry, and commercially available boron-based drugs are rare. In contrast to hydrocarbons, boranes prefer the formation of polyhedral clusters via delocalized 3c2e bonds, such as polyhedral dicarba-closo-dodecaborane(12) (closo-C2B10H12). These clusters have remarkable biological stability, and the three isomers, 1,2- (ortho), 1,7- (meta), and 1,12-dicarba-closo-dodecaborane(12) (para), have attracted much interest due to their unique structural features. Furthermore, anionic nido clusters ([7,8-C2B9H11]2−), derived from the neutral icosahedral closo cluster 1,2-dicarba-closo-dodecaborane(12) by deboronation followed by deprotonation are suitable ligands for transition metals and offer the possibility to form metallacarboranes, for example via coordination through the upper pentagonal face of the cluster. The isolobal analogy between the cyclopentadienyl(–1) ligand (Cp−) and [C2B9H11]2− clusters (dicarbollide anion, Cb2−) is the motivation in using Cb2− as ligand for coordination to a metal center to design compounds for various applications. This review focuses on potential applications of half- and mixed-sandwich-type transition metal complexes in medicine.


2021 ◽  
Vol 159 ◽  
pp. 113080
Author(s):  
Thaynara C. Pin ◽  
Lívia B. Brenelli ◽  
Viviane M. Nascimento ◽  
Aline C. Costa ◽  
Yunqiao Pu ◽  
...  

1990 ◽  
Vol 29 (14) ◽  
pp. 2599-2607 ◽  
Author(s):  
Nathaniel W. Alcock ◽  
Peter A. Padolik ◽  
Graham A. Pike ◽  
Masaaki Kojima ◽  
Colin J. Cairns ◽  
...  

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