scholarly journals Elucidating the Role of Hydrogen Bond Donor and Acceptor on Solvation in Deep Eutectic Solvents Formed by Ammonium/Phosphonium Salts and Carboxylic Acids

2020 ◽  
Vol 8 (49) ◽  
pp. 18286-18296
Author(s):  
Muhammad Qamar Farooq ◽  
Gabriel A. Odugbesi ◽  
Nabeel Mujtaba Abbasi ◽  
Jared L. Anderson
2019 ◽  
Vol 281 ◽  
pp. 423-430 ◽  
Author(s):  
Matteo Tiecco ◽  
Federico Cappellini ◽  
Francesco Nicoletti ◽  
Tiziana Del Giacco ◽  
Raimondo Germani ◽  
...  

2020 ◽  
Vol 22 (28) ◽  
pp. 16125-16135 ◽  
Author(s):  
Monika Lukaczynska-Anderson ◽  
Mesfin Haile Mamme ◽  
Andrea Ceglia ◽  
Krista Van den Bergh ◽  
Joost De Strycker ◽  
...  

Water concentration and hydrogen bond donor have both a big influence in the coordination of Ni cations in deep eutectic solvents, and will therefore affect their electroreduction.


2020 ◽  
Vol 503 ◽  
pp. 112319 ◽  
Author(s):  
Fabiane Oliveira Farias ◽  
Jorge F.B. Pereira ◽  
João A.P. Coutinho ◽  
Luciana Igarashi-Mafra ◽  
Marcos R. Mafra

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Christoph A. Bauer ◽  
Gisbert Schneider ◽  
Andreas H. Göller

Abstract We present machine learning (ML) models for hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD) strengths. Quantum chemical (QC) free energies in solution for 1:1 hydrogen-bonded complex formation to the reference molecules 4-fluorophenol and acetone serve as our target values. Our acceptor and donor databases are the largest on record with 4426 and 1036 data points, respectively. After scanning over radial atomic descriptors and ML methods, our final trained HBA and HBD ML models achieve RMSEs of 3.8 kJ mol−1 (acceptors), and 2.3 kJ mol−1 (donors) on experimental test sets, respectively. This performance is comparable with previous models that are trained on experimental hydrogen bonding free energies, indicating that molecular QC data can serve as substitute for experiment. The potential ramifications thereof could lead to a full replacement of wetlab chemistry for HBA/HBD strength determination by QC. As a possible chemical application of our ML models, we highlight our predicted HBA and HBD strengths as possible descriptors in two case studies on trends in intramolecular hydrogen bonding.


2011 ◽  
Vol 22 (5) ◽  
pp. 1015-1030 ◽  
Author(s):  
Damanjit Kaur ◽  
Ritika Sharma ◽  
Darpandeep Aulakh

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 278 ◽  
Author(s):  
Heng Zhang ◽  
Jinyan Lang ◽  
Ping Lan ◽  
Hongyan Yang ◽  
Junliang Lu ◽  
...  

Four deep eutectic solvents (DESs), namely, glycerol/chlorocholine (glycerol/ChCl), urea/ChCl, citric acid/ChCl, and oxalic acid/ChCl, were synthesized and their performance in the dissolution of cellulose was studied. The results showed that the melting point of the DESs varied with the proportion of the hydrogen bond donor material. The viscosity of the DESs changed considerably with the change in temperature; as the temperature increased, the viscosity decreased and the electrical conductivity increased. Oxalic acid/ChCl exhibited the best dissolution effects on cellulose. The microscopic morphology of cellulose was observed with a microscope. The solvent system effectively dissolved the cellulose, and the dissolution method of the oxalic acid/ChCl solvent on cellulose was preliminarily analyzed. The ChCl solvent formed new hydrogen bonds with the hydroxyl groups of the cellulose through its oxygen atom in the hydroxyl group and its nitrogen atom in the amino group. That is to say, after the deep eutectic melt formed an internal hydrogen bond, a large number of remaining ions formed a hydrogen bond with the hydroxyl groups of the cellulose, resulting in a great dissolution of the cellulose. Although the cellulose and regenerated cellulose had similar structures, the crystal form of cellulose changed from type I to type II.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Guochao Xu ◽  
Hao Li ◽  
Wanru Xing ◽  
Lei Gong ◽  
Jinjun Dong ◽  
...  

Abstract Background Biobutanol is promising and renewable alternative to traditional fossil fuels and could be produced by Clostridium species from lignocellulosic biomass. However, biomass is recalcitrant to be hydrolyzed into fermentable sugars attributed to the densely packed structure by layers of lignin. Development of pretreatment reagents and processes for increasing surface area, removing hemicellulose and lignin, and enhancing the relative content of cellulose is currently an area of great interest. Deep eutectic solvents (DESs), a new class of green solvents, are effective in the pretreatment of lignocellulosic biomass. However, it remains challenging to achieve high titers of total sugars and usually requires combinatorial pretreatment with other reagents. In this study, we aim to develop novel DESs with high application potential in biomass pretreatment and high biocompatibility for biobutanol fermentation. Results Several DESs with betaine chloride and ethylamine chloride (EaCl) as hydrogen bond acceptors were synthesized. Among them, EaCl:LAC with lactic acid as hydrogen bond donor displayed the best performance in the pretreatment of corncob. Only by single pretreatment with EaCl:LAC, total sugars as high as 53.5 g L−1 could be reached. Consecutive batches for pretreatment of corncob were performed using gradiently decreased cellulase by 5 FPU g−1. At the end of the sixth batch, the concentration and specific yield of total sugars were 58.8 g L−1 and 706 g kg−1 pretreated corncob, saving a total of 50% cellulase. Utilizing hydrolysate as carbon source, butanol titer of 10.4 g L−1 was achieved with butanol yield of 137 g kg−1 pretreated corncob by Clostridium saccharobutylicum DSM13864. Conclusions Ethylamine and lactic acid-based deep eutectic solvent is promising in pretreatment of corncob with high total sugar concentrations and compatible for biobutanol fermentation. This study provides an efficient pretreatment reagent for facilely reducing recalcitrance of lignocellulosic materials and a promising process for biobutanol fermentation from renewable biomass.


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