Solvent Salt Research Articles

Enhancing fractionation of terpenoids and terpenes in citrus essential oils by a biphasic extraction system

Efficient deterpenation of essential oils is crucial for obtaining high value-added products. In this work, a biphasic extraction system integrated with associative extraction was utilized to enhance fractionation of terpenoids and terpenes, where organic salt and organic solvent were employed as extractants in each phase. Ten different organic solvents were evaluated in terms of their phase behavior, extraction performance, and EHS-related properties. The positive or negative effect of organic solvents on biphasic extraction performance was elucidated through molecular dynamics simulations and FT-IR spectra analysis. The results indicate that an organic solvent lacking hydrogen bonding ability can reduce its interaction with organic salt or terpenoids, thereby exerting a positive contribution to biphasic extraction. For crude orange sweet essential oil, the biphasic system containing tetrabutylammonium chloride and n-hexane achieves a 6.2-fold concentration of terpenoids, demonstrating its effectiveness in enhancing extractive deterpenation of essential oil.

Absorption characteristics and molecular mechanism of a low viscosity iron-based ionic liquid for removing H2S

Aiming at the problem of by-product salt and volatile solvent component in industrial liquid redox process of H2S removal. A new absorbent, a 1-butyl-3-methylpyridine iron-based ionic liquid (rFeCl3/[BMP]Cl) with three iron-pyridine ratios (r=0.6, 0.8, and 1.0), was synthesized. The physicochemical properties and H2S solubility of rFeCl3/[BMP]Cl were measured and modeled. The molecular mechanism of chemical absorption of H2S by iron-based ionic liquids was explained from the interaction energy, reduced density gradient (RDG) and atoms in molecules (AIM) topology analysis, and standard reaction equilibrium constant by quantum chemical calculation. It was found that rFeCl3/[BMP]Cl have low viscosity, high solubility, and good thermal stability. Its Bronsted acidity avoids by-product salts produced in the absorption of H2S. The hydrophobicity makes the ionic liquid not diluted by the generated water during the absorption. The results of quantum chemical calculations show that rFeCl3/[BMP]Cl-H2S has moderate intermolecular interaction and large reactivity, which is consistent with the experimental results of the Henry's coefficient and reaction equilibrium constant.

Suppression of potasside reaction in localized high concentration electrolytes utilizing fluorine-substituted benzene as bifunctional additive for potassium-metal batteries

Localized high-concentration electrolytes (LHCEs) have unique solvation structures that do not affect the original salt–solvent coordination from highly concentrated electrolytes. LHCEs enable a wide electrochemical voltage window and mitigate the extensive dendritic growth of metallic anodes. However, in K metal batteries, LHCE undergoes undesirable side reactions because of potasside (K−), triggering aggressive chemistry with a diluent, represented as hydrofluoroethers (HFEs), eventually resulting in poor cycle life. In this study, 1, 3, 5-trifluorobenzene (TFB) was introduced as a functional additive to prevent the parasitic K− reaction. The three symmetrically substituted fluorines prevented TFB from disrupting the as-formed solvation structure of LHCE located in the outer sphere. This characteristic increases the reaction energy barrier between K− and HFE, suppressing the deterioration of the metal anode by adding only 3 wt.% of TFB in LHCE. Moreover, TFB preferentially decomposes at each electrode because of its molecular energy level and increases the reversibility of the cell, reducing unnecessary consumption of electrolytes with a stable interface. This study discusses a novel method to prevent the K− reaction at the electrolyte level and the utilization of LHCE in K batteries to pursue higher energy densities, sustaining the advantage of using a metal anode.

Synthesis, spectroscopic, biological and structural characterizations for the gold(III), platinum(IV), and Ruthenium(III) ceftriaxone drug complexes

Three new metal complexes of ceftriaxone (cef), incorporating platinum(IV), gold(III), and ruthenium(III), were prepared. The complexes were prepared using a 1:2 molar ratio between ceftriaxone sodium salt (Na2cef) to AuCl3, PtCl4, and RuCl3 salts in methanol solvent. The as-synthesized complexes were characterized using microanalytical techniques for C, H, N, and S elements, magnetic and molar conductance measurements, as well as spectroscopic methods including FTIR, 1H NMR, and UV-Vis. The shape, morphology and size calculations have been examined using SEM, TEM, and X-ray diffraction data. The cef complexes were six-coordinate systems possessing a distorted octahedral geometry. Through the oxygen of both triazine and carboxylate moieties with the chemical formulae [Au(cef)2(Cl)(H2O)] (I), [Pt(cef)2(Cl)2] (II), and [Ru(cef)2(Cl)(H2O)] (III) the antibiotic cef acts as a bidentate ligand towards three metal ions. The newly created complexes demonstrated antibacterial activity showing efficacy in comparison to the cef sodium ligands. In vitro, antibacterial assays against specific microorganisms were evaluated to assess the antibacterial activities of the complexes. Cytotoxicity assays for cef complexes were conducted for HepG-2 and MCF-7 cell lines, representing human hepatocellular carcinoma and breast cancer, respectively. A value of 22.4 g and 26.2 g for 50% inhibitory concentration (IC50), respectively, for HepG-2 and MCF-7 were obtained for [Ru(cef)2(Cl)(H2O)] (III). KEY WORDS: Ceftriaxone sodium, Gold, Ruthenium, Platinum, Complexes, FTIR, IC50 Bull. Chem. Soc. Ethiop. 2024, 38(4), 937-948. DOI: https://dx.doi.org/10.4314/bcse.v38i4.10

Durable, multifunctional cotton fabrics with in situ deposited micro/nanomaterials for effective self–cleaning, oil–water separation and antibacterial activity

The facile modification of cotton fabrics for excellent self–cleaning, oil–water separation, and antibacterial activity is of great interest for multifunctional requirements. Herein, a durable, robust, fluorine–free multifunctional cotton fabric was fabricated via in-situ growing zeolitic imidazolate framework-67 (ZIF-67) on the cotton surface, followed by depositing hydrophobic SiO2 (H-SiO2) nanoparticles synthesized via an improved Stöber reaction. Meanwhile, the abundant hydroxyls of the cotton fabrics provided the necessary ion interaction sites for the uniform deposition of micro/nanomaterials, confirmed by the visualized Raman imaging technology. The resultant H-SiO2/ZIF-67@cotton fabric exhibited superhydrophobicity with a water contact angle of 159° and versatile self–cleaning, antifouling, oil–water separation, as well as prominent antibacterial activity against S. aureus and E. coli. At the same time, the superhydrophobic cotton fabric possessed excellent durability and stability against harsh environments, including abrasion, washing, acid, base, salt, and organic solvents. This facile technique can be applied for large-scale production of multifunctional superhydrophobic cotton fabrics due to its easy operation, low cost, and environmental friendliness.

Ether-Water Co-Solvent Electrolytes Enhanced Vanadium Oxide Cathode Cyclic Behaviors for Zinc Batteries.

Vanadium-based compounds are fantastic cathodes for aqueous zinc metal batteries due to the high specific capacity and excellent rate capability. Nevertheless, the practical application has been hampered by the dissolution of vanadium in traditional aqueous electrolytes owing to the strong polarity of water molecules. Herein, we propose a hybrid electrolyte made of Zn(ClO4)2 salt in tetraethylene glycol dimethyl ether (G4) and H2O solvents to upgrade the cycle life of Zn//K0.486V2O5 battery. The G4 jointly solvates with Zn2+ ions and replaces a portion of the H2O molecules in the Zn2+ solvation sheath. It forms a strong bond with H2O, reducing its activity, and significantly inhibiting vanadium dissolution and water-induced parasitic reaction. Consequently, the optimized electrolyte with H2O and G4 volume ratio of 5 : 5 enhances the cycling stability of Zn//K0.486V2O5 battery, enabling it to reach up to 600 cycles. In addition, the battery demonstrates a satisfactory reversible capacity of 475.7 mAh g-1 and excellent rate performance attributed to the moderate ionic conductivity (28.8 mS cm-1) of the hybrid electrolyte. Last but not least, in the optimized electrolyte, the symmetric Zn//Zn cells deliver a long cycling performance of 400 h, while the asymmetric Zn//Cu cells shows a high average coulombic efficiency of 97.4 %.

Ethidium benzoate methanol monosolvate.

In the title salt solvate (systematic name: 8-amino-5-ethyl-6-phenyl-phenanthridin-5-ium benzoate methanol monosolvate), C21H20N3 +·C6H5CO2 -·CH3OH, two ethidium cations, C21H20N3 +, dimerize about a twofold axis through π-π inter-actions [inter-centroid separation = 3.6137 (4) Å]. The benzoate anions are connected through hydrogen bonding with the -NH2 groups of the ethidium cations and the -OH group of the MeOH mol-ecule. The MeOH mol-ecule also accepts a hydrogen bond from the -NH2 group of the ethidium cation. The result is a one-dimensional hydrogen-bonded chain along the b-axis direction.

Metallothermic reduction of Cerium Chloride in molten Salt using Li, Na, and Ca Metal

Options for reducing purified metal chlorides to metallic form were evaluated in support of the development of a metal purification process based on the conversion of impure metal via hydriding followed by chlorination. Metallothermic reduction of CeCl3 was tested using Li, Ca, and Na as reductant metals with and without a molten salt solvent in MgO and Y2O3-coated MgO crucibles. The effects of added reductant metal form, crucible material and dimensions, and mixture hold times above Ce melting temperature were studied. Direct contact of Li and CeCl3 was ineffective due to their immiscibility. A low-density alloy was formed between Li and Ce using Li in a LiCl solvent. Na was ineffective at reducing CeCl3 to any measurable degree. The highest percent recovery (71.4 %) and consolidation of Ce was achieved when using Ca in a CaCl2-NaCl solvent with 99.8 % removal of CeCl3 from the salt. Side reaction with MgO crucibles was found to be at least partially responsible for reduced Ce recovery.

Investigation of the structure and multi-stimuli-responsive behavior of ion-associated salt solvates of binary crystals

Investigation of the intermolecular interactions and crystal packing to understand crystal growth is a prime objective of crystal engineering. Solvent molecules within crystal assist the supramolecular aggregation, however, control over their lattice incorporation remains uncertain. In this work, we report three solvates of an ionic organic salt of a diazo-naphthol sulfonate (1) and 1,10-phenanthroline with one (2), three (3) and four (4) lattice water molecules. Attempts to isolate the dihydrate form were unsuccessful, while the monohydrate of 1 has been crystallised for comparative structural investigations. Structural studies reveal the existence of intriguing sulfonate-diazo intermolecular interactions responsible for centrosymmetric dimerization of the organosulfonate 1, which also persist in 2–4, validating higher preference and robustness of the synthon. Repetitive aggregation of the sulfonate-diazo interaction in 1 leads to the formation of linear π-stacked aggregate, which further aggregates through the lattice water molecules. The structural comparison indicates the preferential formation of the organo-sulfonate dimers in hydrated salts 2–4. Further, sandwich tetramers in 2 and 4 are formed by charge transfer interaction of the organo-sulfonate dimers with pyridinium coformer on either side, which are further associated by the lattice water molecules into disparately packed 3-dimensional supramolecules. The organo-sulfonates in 3 form a similar type of extended π-stacked chains as in 1, which are flanked by pyridinium ions to form hydrogen-bonded tapes, which are helped by the lattice water molecules to grow as segregated stacked layer solid. The characteristic absorption frequency of the diazo functionality is blue-shifted in infrared spectra of the cocrystal forms, indicating the presence of charge transfer interactions. The presence of dynamic solvent and protons in the lattice makes the solid forms multi-stimuli-responsive to exhibit mechano and vapochromic response. These phenomena have been studied in detail with the help of thermal, spectroscopic, and powder-diffraction studies.

Perbedaan Derajat Aglutinasi Pemeriksaan Golongan Darah Metode Tabung Berdasarkan Konsentrasi Suspensi Sel 5% Segera Periksan Dengan Lama Penyimpanan 5 Hari

Background: ABO b;ood group examination is an examination carried out to determinate the type of blood group in humans that detects the presence of antigens on the surface of the red blood cell membrane by means of the Tube Method various consentrations of erythrocyte cell suspension,namely 5%, 10% and 15%. Research purpose: To determinate the effect of various consentrations of erythrocyte cell suspension with ready-to-use 0,9% NaCl and 0,9% table salt solvent on the degree of agglutination in blood group examination Tube method. Research method: This research is a pure experimental study with a total sample 41 people, this study was conducted on January 16-20, 2023 at the Muhammadiyah Palembang IKesT Clinical Pathology Laboratory. Results: The results showed that the blood group examination was done by the tube method with a concentration of erythrocyte cell suspension, namely 5%, 10% and 15% with 0,9% NaCl solvent ready-to-use and 0,9% NaCl, table salt solvent resulting in a degree of agglutination of +4. The Kruskal-wallis test result in the Cell Grouping method obtained 0,000 and in the Serum Grouping method obtained 0,051. Conclusion: The conclusion in this study is that there is no effect of various consentrations of erythrocyte cell suspension with ready-to-use 0,9% NaCl and 0,9% NaCl Solvent Kitchen Salt on the degree of agglutination in blood group examination Tube Method so that 0,9% NaCl solvent from table salt can be used as an alternative to ready-to-use 0,9% NaCl reagent in blood group tests by tube method. 
 Keywords: Blood type, Aglutination

Lithium ion Speciation in Cyclic Solvents: Impact of Anion Charge Delocalization and Solvent Polarizability.

The increasing demand for lithium batteries has triggered the search for safer and more efficient electrolytes. Insights into the atomistic description of electrolytes are critical for relating microscopic and macroscopic (physicochemical) properties. Previous studies have shown that the type of lithium salt and solvent used in the electrolyte influences its performance by dictating the speciation of the ionic components in the system. Here, we investigate the molecular origins of ion association in lithium-based electrolytes as a function of anion charge delocalization and solvent chemical identity. To this end, a family of cyano-based lithium salts in organic solvents, having a cyclic structure and containing carbonyl groups, was investigated using a combination of linear infrared spectroscopy and ab initio computations. Our results show that the formation of contact-ion pairs (CIPs) is more favorable in organic solvents containing either ester or carbonate groups and in lithium salts with an anion having low charge delocalization than in an amide/urea solvent and an anion with large charge delocalization. Ab initio computations attribute the degree of CIP formation to the energetics of the process, which is largely influenced by the chemical nature of the lithium ion solvation shell. At the molecular level, atomic charge analysis reveals that CIP formation is directly related to the ability of the solvent molecule to rearrange its electronic density upon coordination to the lithium ion. Overall, these findings emphasize the importance of local interactions in determining the nature of ion-molecule interactions and provide a molecular framework for explaining lithium ion speciation in the design of new electrolytes.

Insight into the solvation and dynamic behaviors of lithium salt in water-in-bisalt electrolytes

Through a combination of molecular dynamics simulations and experimental approaches, the solvation structure and diffusion behavior of Li+ was investigated in water-in-bisalt electrolytes formed by introducing a second lithium salt (LiBF4, LiNO3, LiOAc) into the LiTFSI aqueous electrolyte. The calculation and experimental results indicate that nanostructures of water-in-bisalt electrolytes include “water-rich” and “anion-rich” domains. When LiBF4 is added, Li+ is mostly located in the water-rich domain, effectively increasing the diffusion coefficient of Li+. This electrolyte exhibits a higher conductivity and a much lower price compared to mono-LiTFSI electrolytes, On the contrary, with the addition of LiOAc, OAc− will strongly coordinate with Li+ to change the solvation structure of solvent separated ion pairs (Li+(H2O)4) to aggregates, which results in the decrease of Li+ diffusion coefficient. These fundamental insights highlight the correlation of microstructural and dynamic heterogeneities of water-in-bisalt electrolytes, which are expected to trigger rational design of solvation and dynamic behaviors of advanced aqueous electrolytes.

Effect of Water in the Trimer‐Cyclisation of Alkynyl Ketone

AbstractA trimer‐cyclisation reaction of propiolate esters yielded 1,3,5‐benzenetricarboxylate tri‐esters in water. The reaction proceeded selectively in the presence of secondary or tertiary amine salts in pure water solvent. Other organic solvents, such as dimethyl formamide, tetrahydrofuran, and ethanol, afforded a 1 : 1 adduct of propiolate and amine. The hydrogen bonding characteristics of water stabilised the proposed intermediate in a conformation that promoted the final cyclisation. The synthesis can be successfully conducted in water–a universal and an eco‐friendly solvent.

A novel synergistic intensification method for CO2 absorption by metal salt and task-specific ionic liquids hybrid solvent in microchannel reactor

A novel metal salt-promoting mass transfer intensification method for CO2 absorption into task-specific ionic liquids aqueous solution was proposed. The mass transfer intensification and intrinsic mechanisms of different concentrations of metal salts (NaBF4, KBF4, KCl, and CuCl2) with task-specific ionic liquids (1-aminopropyl-3-methylimidazolium tetrafluoroborate [Apmim] [BF4]) aqueous solutions for CO2 capture process were visually investigated using a microchannel reactor. The results showed that adding metal salts could remarkably enhance the interaction between metal cations and ionic liquid anions, thereby decreasing the interaction between anions and cations within the ionic liquid molecules and promoting the chemical reaction between ionic liquid cations and CO2. Under the condition of the same salt concentration, the addition of KBF4 has more obvious enhancement for mass transfer in CO2 absorption process. The mass transfer coefficient increases as the gas-liquid phase flow rate rise under slug flow condition. In addition, based on the effects of metal salt concentration, absorbent density, and gas-liquid phase flow rate on the CO2 volumetric mass transfer coefficient kLa, a new correlation for predicting the volumetric mass transfer coefficient of CO2 absorption into the hybrid solvent in microchannel reactor was proposed and validated.

Novel electrolyte assisted ultralow-temperature zinc battery

Secondary battery is an indispensable component in energy storage as it can uninterruptedly store the energy and release it when being required. Among them, zinc (Zn) rechargeable battery gains much attention due to its cost advantage. However, poor climate adaptation much weaken the competitiveness, and temperature-induced deterioration can be mainly blamed on the slow reaction-kinetics of Zn anode under low temperature. Under this scenario, an anti-freezing electrolyte with Zinc (II)Bis(trifluoromethanesulfonyl)imide (Zn(TFSI)2) salt and ternary solvents of acetonitrile (AN), methyl acetate (MA) and dichloromethane (DCM) is proposed. It successfully broadens the working temperature of Zn secondary battery to − 90 °C. The elaborately regulated solvation can ensure smooth ion-transfer in liquid zone, more importantly, it expedites the desolvation without much affecting the interface transportation. With the optimized electrolyte configuration, reversible Zn plating/stripping at ultra-low temperature has been realized. The Zn|polytriphenylamine (PTPAn) battery thus can reserve 70 % capacity at − 80 °C, and present extremely stable cycling and impressive rate capability at − 80 °C and − 60 °C. The results well address the kinetics issues encountered in the low-temperature Zn secondary battery, and reveals that only with appropriate solvation, the high ion-permeability of the interface as well as easy de-solvation can be guaranteed. The work provides a guideline for designing advanced electrolyte, and supplies a reliable and effective strategy for the all-weather electrochemical energy storage.

Study of restricted diffusion of lithium salts in diglyme confined in mesoporous carbons as a model for cathodes in lithium-air batteries.

The Li+ ion mobility through the porous cathode is a critical aspect in the development of commercial Li-air batteries. The bulk transport properties of lithium salts in organic solvents are not reliable parameters for the design of this type of battery since confinement could significantly modify the transport properties, especially when pore diameters are below 10 nm. In this work, we studied the effect of the carbon mesostructure and surface charge on the diffusion of LiTf and LiTFSI salts dissolved in diglyme, typical electrolytes for lithium-air batteries. Interdiffusion coefficients of the salts were determined using a conductimetric method. NMR spectroscopy and relaxometry were used to explore the effect of the carbon structure and the surface charge density on the interaction between the electrolytes and the pore wall. We showed that carbon micro/mesoporous structure plays a critical role in the transport properties of the electrolyte, producing a decrease of up to 2-3 orders of magnitude in the salt interdiffusion coefficients when going from bulk solutions to pores below 4 nm in diameter. It was observed that for pores 25 nm in diameter, the reduction in the diffusion coefficient can be mainly ascribed to the porosity of the sample, giving tortuosity factors around 1. However, for smaller pore sizes (1-10 nm diameter) bigger tortuosity coefficients were observed and were related to strong ion-pore wall interactions. Moreover, it was noticed that the ratio between the diffusion coefficients of the two studied salts dissolved in diglyme, is different in bulk and under confinement, demonstrating that the interactions of the ions with the charged pore wall probably compete with the cation-anion interactions, affecting salt association under confinement.

Boron-containing fullerene-based salts with cyclic carbonate solvents as electrolytes for Li-ion batteries and beyond.

Replacement of carbon atoms by a heteroatom in fullerene is a promising route that enhances the electronic properties of fullerenes and results in hetero fullerene-based effective agents ensuring applications in vivid fields of the solar cell, cathode materials for batteries, etc. Towards the development of new electrolyte salts, attention has been paid to facilitating ion mobility in particular and moderate stability of the anions in addition. From the atomistic molecular dynamics simulation studies, for the first time, we uncover that the boron-containing hetero fullerene, C59B- anion-based LiC59B, and NaC59B salts in cyclic carbonate solvents can act as efficient electrolytes by improving the transport phenomenon of the metal ions in solution, importantly for Li+ and satisfactorily for Na+ as compared to their commonly used BF4- anion based salts. Additionally, our study revealed that apart from LiC59B, and NaC59B salts, C58B22- based MgC58B2 salt can facilitate the ionic conductivity of the electrolyte. The properties of the proposed electrolyte under an electric field and different temperatures were investigated. Some of the bulk properties of the used electrolytes to some extent were found to be improved in the presence of these salts. The first principle-based electrochemical calculations further justify the stability of the proposed anions. The initial investigation from the Reactive force-field (ReaxFF) based atomistic simulations study elucidates that LiC59B reduces the decomposition of the EC solvent compared to LiBF4 and facilitates solvent stability.

Spectroscopic and thermodynamic characterization of a cobalt-verdazyl valence tautomeric system. influence of crystal structure, solvent and counterion.

Crystallization of the verdazyl-based valence tautomeric ion [Co(dipyvd)2]2+ (where dipyvd is the radical ligand 1-isopropyl-3,5-di(2'-pyridyl)-6-oxoverdazyl) with a variety of different counterions results in materials that show varying degrees of valence tautomeric (VT) transition in the solid state. The X-ray structure of the SbF6 salt at 150 K reveals a localized structure for the S = 1/2 tautomer, with a Co3+ cation and distinct anionic and radical ligands. Comparison with the structure of the same material at 300 K reveals large structural changes in the ligand as a result of the valence tautomeric equilibrium. Data for the S = 3/2 form is less conclusive; X-ray spectroscopy on the PF6 salt suggests a degree of low spin Co2+ character for the S = 3/2 tautomer at very low temperature though this is inconsistent with EPR data at similar temperatures and structural information at 150 K. Magnetic measurements on the [BArF4]- and triflate salts in organic solvents show that the VT equilibrium is dependent on solvent and ion pairing effects.

Technologies used in natural gas dehydration: Problems and solutions

This article provides a thorough exploration of diverse technologies utilized in the dehydration of natural gas. These include glycol absorption, desiccant adsorption, solvent salt adsorption, chemical cooling, and hydrate suppression processes. The content delves into the merits of each technology, outlines common challenges encountered, and presents optimal solutions. Notably, the article focuses on the specific challenges arising from glycol absorption, particularly in select gas fields and underground gas storage facilities in Uzbekistan. This comprehensive examination of dehydration technologies, coupled with the in-depth analysis of solutions for glycol absorption issues, enhances our collective understanding of gas processing methodologies. By addressing the intricacies of each technology and proposing effective solutions, the article stands as a valuable resource for professionals and researchers immersed in the realm of natural gas dehydration. The insights offered contribute to refining and advancing gas processing strategies, making it an essential reference for those navigating the complexities associated with this critical aspect of the energy industry.

Understanding the Reaction Mechanism and Kinetics of Mediated Li-O2 Batteries Using Flow Set-Ups and Cyclic Voltammetry

Li-O2 batteries are very promising candidates for electromobility because of their very high theoretical energy density. Moreover, they are composed of abundant materials, as opposed to Li-ion batteries, which would make them a greener and cheaper alternative. The principal reaction in Li-O2 batteries is the formation of lithium peroxide during discharge via the oxygen reduction reaction (ORR), that is then oxidised during the charge by the oxygen evolution reaction (OER). One of the major challenges of Li-O2 batteries is related to the insulating nature of their discharge product, that significantly limits the capacity and hinders performance. A strategy to overcome this is by using redox mediators (RMs), which shuttle electrons from the electrode surface to the solution and thus facilitate a solution-based mechanism for the formation of large crystals. Understanding the reaction kinetics of these RMs can therefore aid in increasing the battery performance.Quinones, specifically 2,5-Di-tert-butyl-1,4-benzoquinone (DBBQ),is a commonly used discharge RM in this type of batteries. However, their reaction kinetics and how these vary with different electrolyte conditions are not yet well understood. DBBQ undergoes two single electron reductions, whose potentials and kinetics vary with salt concentrations and solvent having a direct effect on its ability to mediate the ORR.In this work, we have developed a Li-O2 flow cell to study the reaction mechanism and kinetics of DBBQ, and performed cyclic voltammetry (CV) studies to better understand how these vary with changing solvent and salt conditions. In the Li-O2 flow set-up the battery is positioned outside the nuclear magnetic resonance (NMR) magnet and plastic tubing then runs through the NMR and electron paramagnetic resonance (EPR) spectrometers. In this way, the reduction of the DBBQ can be monitored while the battery is cycling. In the proton NMR, the neutral DBBQ signals disappear on discharge as the singly reduced DBBQ semiquinone monoanion is a radical. The fast electron exchange between the neutral and radical species broaden out the NMR signals on discharge as the EPR signal grows. On charge, the neutral DBBQ signal reappears and the EPR signal disappears. The Li-O2 flow set-up is very sensitive to air and moisture exposure as the tubing is not perfectly impermeable to them. Therefore, having the CVs as a complementary method to study the reaction mechanisms and kinetics is very useful.We have developed a theoretical framework of Li-coupled electron transfer reactions that can predict the electrochemical kinetics in the presence of high and low donor number solvents and used to quantify thermodynamic and kinetic parameters. We define E0 app and k0 app as the apparent thermodynamic and kinetic parameters that describe the overall system and can be derived from the Nernst equation and Butler Volmer kinetics. These overall descriptors depend on the pathway the reaction takes (Figure 1). The different pathways in different solvents/salts are due to changes in the Li+ solvation strength as well as the competing ionic association of the counter anion.Experimentally, we have shown that in three different solvents, DME, tetraglyme and DMSO the behaviour of DBBQ can be explained by this theoretical framework. In DME, the DBBQ behaviour is most reminiscent of pathway 1 where the kinetics slow down with increasing Li+ concentration. In DMSO the kinetics present a maximum at Li+ concentrations around 1M. Simulations and fitting of the CV experiments in DMSO for the first reduction are in good agreement with pathways 2 and 3, while in tetraglyme it is harder to explain the trends as they do not fit into just one of the pathways.In conclusion we have studied the mechanism and kinetics of DBBQ as a RM for Li-O2 batteries with an in-situ flow set up and CVs and build a theoretical framework to understand how these vary in different electrolyte conditions. This method can be extended to study both the second reduction of DBBQ and other discharge and charge RMs for Li-O2 batteries. Figure 1