Donor Number Research Articles

Achieving Highly Reversible Zinc Anodes via N, N-Dimethylacetamide Enabled Zn-Ion Solvation Regulation.

Although aqueous zinc-ion batteries (ZIBs) are promising for scalable energy storage application, the actual performance of ZIBs is hampered by the irreversibility. Optimization of electrolyte composition is a relatively practical and facile way to improve coulombic efficiency (CE) and Zn plating/stripping reversibility of ZIBs. N,N-Dimethylacetamide (DMA) has a higher Gutmann donor number (DN) than that of H2 O, abundant polar groups, and economic price. Herein, a mixture electrolyte containing 10vol% DMA and ZnSO4 , which has an enhanced Zn reversibility almost fourfold higher than that of pure ZnSO4 electrolyte, is demonstrated. The density functional theory (DFT) calculation and spectroscopic analysis reveal DMA has the ability to reconstruct the solvation structure of Zn2+ and capture free water molecules via forming Hbonds. The inhibited dendrite growth on Zn anode is further clarified by an in situ characterization. This work provides a feasible way for the development of long-lifespan ZIBs.

Inverse gas chromatography as a tool for screening materials: The relation between Lewis acid–base constants and triboelectric charge density of polymers

Since Saint-Flour and Papirer first introduced Gutmann's acceptor number and donor number parameters into the inverse gas chromatography (IGC) field in 1982, IGC has become an important technology for the measurement of surface Lewis acid–base properties of solid materials. However, introducing new roles of Lewis acid–base parameters, especially using them to predict material properties rather than just explain material properties, is an important aspect in developing IGC technology. In this paper, we first introduce the Schultz and Abraham methods for measurement of acid–base properties and discuss the traditional role of acid–base parameters. Then, we present a relation between the ratio of acid–base constants, Ka/Kb, and triboelectric charge density of some polymers to prove the possible new application field of IGC.

Effect of polar molecular organic solvents on non-aqueous solvent extraction of rare-earth elements

The extraction and separation of five different rare-earth elements, La, Nd, Eu, Dy and Yb, from an aqueous chloride solution and from different chloride non-aqueous solutions using the solvating extractant Cyanex 923 was investigated. As previous studies had demonstrated the potential of non-aqueous solvent extraction (NASX) to refine rare earths from ethylene glycol, structural analogues of ethylene glycol (1,2-propanediol and 1,3-propanediol) and to other polar organic solvents (triethylene glycol, dimethylsulfoxide, methanol, N,N-dimethylformamide and N,N-dimethylacetamide) were studied. The extraction data were interpreted in terms of different solvent properties: dielectric constant, Gutmann donor number, molecular structure and hydrogen-bonding capabilities. Remarkable differences were observed between the extraction behaviour from ethylene glycol, 1,2-propanediol and 1,3-propanediol. Therefore, these solvent systems were further studied to elucidate the speciation of the rare-earth elements by optical absorption and luminescence spectroscopy. Based on these studies, both contact-ion-pair formation and solvation strength are assumed to play an important role in the extraction of rare earths by Cyanex 923 from different polar organic solvents. The differences in extraction behaviour can be exploited to fine-tune the separation of rare earths.

Trust and distrust: Identifying recruitment targets for ethnic minority blood donors.

BackgroundWe explore the role of trust, distrust, and the prevailing socio‐political context to better understand why people from ethnic minority communities are less likely to be blood donors compared to people from White communities. Recruiting more ethnic minority donors will enhance representativeness, reduce inequality, and help meet the clinical need to increase the proportion of blood with Ro Kell antigen to treat Sickle Cell Disease (SCD).Study design and methodsA 2 (donor‐status: current donor; non‐donors) by 4 (ethnicity: People from Asian, Black, Mixed and White ethnic backgrounds) quasi‐experiment (N = 981) was conducted to examine perceptions of trust/distrust and their influence on willingness to donate blood, within the socio‐political context of the Windrush scandal and Brexit.ResultsWe identified five domains of trust (‘National Health Service [NHS] and staff,’ ‘NHS Blood and Transplant,’ ‘outgroups,’ ‘individuals’ and ‘politics’), and a single domain of conditional distrust domain. Trust across all the domains was lower, and ‘conditional distrust’ higher for ethnic minorities. Trust in ‘individuals’ and ‘NHSBT’ predicted willingness to donate in non‐donors from ethnic minorities and White non‐donors, respectively. Concerns about the Windrush scandal were related to lower political trust. Viewing Brexit as ‘positive for the UK’ was related to lower trust across domains and reduced willingness to donate in White non‐donors through its influence on reduced trust in NHSBT.ConclusionDistinct domains of trust and distrust are identified, and targeting ‘trust in others’ through conditional cooperation is recommended as a strategy to increase donor numbers from ethnic minority communities.

Perfectly Alternating Copolymerization of Cyclic Anhydrides and Epoxides with Yttrium β-Diketiminate Complexes.

Monometallic yttrium β-diketiminate complexes are active and controlled catalysts for perfectly alternating ring-opening copolymerization of 1-butene oxide and phthalic anhydride under mild conditions. β-Diketiminate ligands with pendant neutral donors were targeted to identify both the impact of donor strength and number of donors on rates of polymerization and the presence of undesirable side reactions. Initiating groups were also varied between alkyls, chlorides, and alkoxides. In the presence of a cocatalyst, the catalysts studied were active for polymerization with minimal side reactions, whereas lack of cocatalysts led to competing homopolymerization of epoxides. While a greater donor strength and a larger number of donors both increase the rate of polymerization, donor strength generally had a bigger impact when a cocatalyst was used. Additionally, alkoxide and chloride initiators proved to be the fastest, with alkyls being more sluggish. These subtle ligand changes significantly impacting polymerization activity lend promise to the facile tunability of rare earth metal complexes to be highly active for the target copolymerization, which renders further research in this area attractive and timely.

A Mathematical Model of a Valve-Controlled Bioreactor for Platelet Production

As blood donor numbers decrease, while demand for platelets increases, hospitals worldwide are becoming increasingly vulnerable to critical platelet shortages. Alternative methods of supplying platelets are therefore required. One approach is to engineer platelets in vitro in a bioreactor. To characterise such a system, we develop a mathematical model of a novel platelet bioreactor described in Shepherd et al. (Biomaterials, 2018, 182, 135–144). The bioreactor consists of upper and lower tube systems, with a cell-seeded porous collagen scaffold situated between them. Flow through the system is driven by gravity, and controlled by valves on each of the inlets and outlets. The bioreactor is long relative to its width, a feature which we exploit to derive a lubrication reduction of the Navier-Stokes equations for flow in the tube systems, coupled to Darcy flow through the porous scaffold. Flow in the tube systems and scaffold are coupled to form a network model for the bioreactor flow. We characterise the effect of geometrical parameters and valve configuration and synchronisation, on the fluxes through the bioreactor and shear stress experienced by cells in the scaffold. The simplicity of the model means that parameter sweeps take only seconds or minutes to perform, making the model a convenient tool for future bioreactor design optimisation.

Multiwavelength spectrophotometric-thermodynamic studies of complexation reactions of newly synthesized triazenes with Hg2+, Pb2+, Zn2+, and Cd2+ in MeOH, EtOH, DMF, and DMSO

The complexation reaction of Hg2+, Pb2+, Zn2+, and Cd2+ cations with four newly synthesized triazene ligands was studied spectrophotometrically in nonaqueous solvents (MeOH, EtOH, DMF, and DMSO) at various temperatures. Stability constants (K1 and K2) and stoichiometries of formed adducts (1:1 and 1:2 ligand to metal ion) were calculated by computer refinement of experimental spectral mole ratio data by SQUAD program. The results indicated that the donor number, dielectric constant, the acceptor number of the solvents play an important role in the complex stability. Besides, the shape and size of the solvent molecules were significant factors in the studied reactions. Between log β1 and log β2, a linear relationship was illustrated for most of the complexes under different conditions. The Van't Hoff equation was used to calculate ΔG°, ΔS°, and ΔH° from the dependence of formation constants on temperature. After calculating thermodynamic data at different temperatures, a good linear correlation was obtained from the TΔS° − ΔH° plot resulting in the entropy-enthalpy compensation for complexation reactions.

Solid Organ Donation and Transplantation Activity in the Eurotransplant Area During the First Year of COVID-19.

Background.Transplantation activity during the first wave of the coronavirus disease 2019 (COVID-19) pandemic was severely affected worldwide. This retrospective analysis aimed to assess the impact of COVID-19 on organ donations and transplantations in the Eurotransplant region during the first 12 mo of the pandemic. Specifically, we compared donor and transplantation numbers during both waves to determine whether transplant systems adapted to this new reality.Methods.All reported organ donations and transplantations from March 1, 2015, to February 28, 2021, were collected from the Eurotransplant International Foundation registry. The observation period from 2020 to 2021 was divided into three 4-mo periods, which were then compared with the corresponding periods of the preceding 5 y. COVID-19 cases for Eurotransplant countries were retrieved from the OurWorldInData.org database.Results.Overall, the number of organ donors decreased by 18.3% (P < 0.0001) and the number of organ transplantations by 12.5% (P > 0.0001) compared with previous years. Pancreas transplantation was the most affected, followed by kidney, liver, heart, and lung transplant. In detail, during period 1, the number of organ donors decreased by 26.2% (P < 0.0001) and the number of organ transplantations by 16.5% (P < 0.0001), in period 2 by 5.5% (P < 0.0091) and 4.9% (P < 0.0001), and in period 3 by 23.1% (P < 0.0001) and 16.4% (P < 0.0001), respectively.Conclusions.Organ donation and transplantation decreased drastically also during the second wave; however, despite the severity of the second wave, the decline was comparable with that of the first wave.

Additive Engineering in Antisolvent for Widening the Processing Window and Promoting Perovskite Seed Formation in Perovskite Solar Cells.

The chlorobenzene (CB) antisolvent is widely used to fabricate high-efficiency perovskite solar cells (PSCs). However, the narrow processing window and the strict volume ratio of a binary mixed solvent limit the fabrication of large-area and high-quality perovskite films. In this work, by systematic investigation of additives with the CB antisolvent, a universal guideline is achieved wherein a small amount of additive with a donor number between 9.0 and 27.0 kcal/mol can significantly widen the antisolvent treating time slot from 2 to 40 s while simultaneously enlarging the processor binary mixed solvent (dimethylformamide/dimethyl sulfoxide) from 7:3 to 0:10. Moreover, this process facilitates the formation of perovskite seeds as templates for perovskite crystal growth, effectively reducing the bulk defects in perovskite films. Finally, the obtained PSCs show remarkable power conversion efficiencies (PCEs) of 22.22 and 19.74% for rigid and flexible devices, respectively.

Gutmann's Donor and Acceptor Numbers for Ionic Liquids and Deep Eutectic Solvents.

An experimental and computational methodology for the analysis of the Lewis acid/base responses of ionic liquids (ILs) and deep eutectic solvents (DES) is proposed. It is based on the donor and acceptor of the electronic charge ability of Lewis acid and bases concepts (donicity and acceptor numbers, DN and AN, respectively) proposed by Viktor Gutmann. The binding enthalpy between the IL/DES with the probe antimony pentachloride (SbCl5) in dichloroethane displays good correlations with experimental data. This approach could serve as a first approximation to predict the responses to H-bonding abilities of new IL or DES. Although useful, the problems encountered to model the electron AN of these solvents limit the usefulness of the approach to completely describe their polarity properties. The experimental data were recorded using UV–Vis spectroscopy for a wide range of ILs and a couple of DES. Two reactions were used as benchmarks to test the reliability of the DN model to discuss the reactivity of real systems in these neoteric solvents.

Electrolyte Solvation Chemistry for the Solution of High-Donor-Number Solvent for Stable Li-S Batteries.

Passivation of the sulfur electrode by insulating lithium sulfide (Li2 S) restricts the reversibility and sulfur utilization of lithium-sulfur (Li-S) batteries. Although electrolytes with high donor number (DN) solvents induce tri-sulfur radical intermediate thus 3D nucleation of Li2 S with fast kinetics can be achieved, their catastrophic reactivities with Li metal hinder practical applications. Here, the use of high DN solvent as an additive instead of as co-solvent to solve their incompatibility between cathode and anode is proposed, by adopting N-methyl-2-pyrrolidone (NMP) as a proof-of-concept. Such a strategy is accomplished by the unique solvation structure of the NMP added electrolyte, where the preference of NMP-Li+ coordination squeezes out partial 1,2-dimethoxyethane (DME) molecules while enriching 1,3-dioxolane (DOL) molecules in the first solvation sheath of Li+ ions. It affords the robust SEI on Li metal from corrosion either by NMP or the dissolved polysulfides. Spectral analyses (Raman and UV-vis) also verify that the coordinated NMP additive preserves its S3 •- radicals stabilization ability as it does as a co-solvent, which effectively improves the sulfur conversion kinetics and reversibility. This approach enables competitive capacity retention and a stable cycling performance of 340 cycles, which is one of the longest lifespans known for the high DN solvent involved Li-S batteries.

Investigation of the Surface Properties of Hexagonal Boron Nitride and Boron Phosphate by Inverse Gas Chromatography at Infinite Dilution.

The boron-based ceramics namely hexagonal boron nitride (h-BN) and boron phosphate (BPO4) were synthesized and characterized by Fourier transform infrared spectroscopy and X-ray diffraction analysis. The surface properties of h-BN and BPO4 were examined by inverse gas chromatography method. The dispersive surface energy and the acidic-basic character of h-BN, and BPO4 surfaces were estimated by the retention time with probes such as n-hexane, n-heptane, n-octane, n-nonane, n-decane, acetone, ethyl acetate, dichloromethane, chloroform and tetrahydrofuran at infinite dilution region. The dispersive surface free energies calculated using both Schultz and Dorris-Gray methods, decreased linearly with increasing temperature. The specific adsorption free energy and the specific adsorption enthalpy corresponding to acid-base surface interactions were determined. By correlating with the donor and acceptor numbers of the probes, the acidic and the basic parameters of the h-BN and BPO4 were calculated. The values obtained for and parameters indicated that h-BN has a basic character, whereas BPO4 has an acidic character.

Acesulfame based Co(II) complex: Synthesis, structural investigations, solvatochromism, Hirshfeld surface analysis and molecular docking studies

A novel acesulfame based Co(II) complex, [Co(acs)2(abz)2].C2H4O, was prepared and structurally elucidated by single crystal X-ray crystallography, UV–Vis, FT-IR spectroscopy and thermal analysis. It is worth mentioning that it is the first acesulfame- based complex documented to date that has a square pyramidal geometry. In addition, the connection of various vibrational frequencies with the crystal structure was also investigated. The studied Co(II) complex shows solvatochromic characteristics in solvent with varying donor numbers, such as dimethylformamide, acetaldehyde, and 1,2-dichloroethane. The NH···O hydrogen bonds stabilize the crystal packing of Co(acs)2(abz)2].C2H4O. The contribution of interactions involving the atoms of the [Co(acs)2(abz)2].C2H4O complex was further investigated using fingerprint plots and Hirshfeld surface analysis with dnorm mapping. However, the most significant contributions to the Hirshfeld surface come from H∙∙∙H (37.1%), C∙∙∙H/H∙∙∙C (18.3%) and O∙∙∙H/H∙∙∙O (33.5%). Furthermore, AutoDock Vina was used to explore the molecular docking interactions of [Co(acs)2(abz)2].C2H4O within the CA IX receptor (PDB: 5DVX) using in-silico simulations.

Sacrificial Co-solvent Electrolyte to Construct a Stable Solid Electrolyte Interphase in Lithium-Oxygen Batteries.

Lithium-oxygen batteries are vital devices for electrochemical energy storage. The electrolyte is a crucial factor for improving battery performance. The high reactivity of lithium metal induces side reactions with organic electrolytes, thus leading to an unstable interface between the anode and electrolyte and poor performance of batteries. In this work, to compensate for the above shortcomings, 1-methylimidazole (MeIm) is introduced to the tetraethylene glycol dimethyl ether (TEGDME) electrolyte to form the TEGDME/MeIm co-solvent electrolyte. Because of the high donor number value of MeIm, the solution-based pathway of discharge products can be triggered. Compared with the single TEGDME electrolyte, the discharge capacity with the TEGDME/MeIm co-solvent electrolyte is increased by more than 2 times. Moreover, the TEGDME/MeIm co-solvent electrolyte can promote the dissociation of Li salt due to the high dielectric constant of MeIm and thus make up for the shortcomings of TEGDME. In addition, due to the lower energy than the lowest unoccupied molecular orbital (LUMO) level of TEGDME, MeIm is decomposed preferentially, and a dense solid electrolyte interphase (SEI) layer is constructed. Then, the decomposition of TEGDME is suppressed. Therefore, the cycle performance of the battery with the TEGDME/MeIm co-solvent electrolyte is 18 times compared to that with the single TEGDME electrolyte.

Risk of Cytomegalovirus Infection with Post-Transplantation Cyclophosphamide in Haploidentical and HLA-Matched Unrelated Donor Transplantation

Post-transplantation cyclophosphamide (PTCy) is effective for graft-versus-host disease (GVHD) prevention but is associated with an increased risk of cytomegalovirus (CMV) infection. The effect of PTCy on CMV infection in matched unrelated donor (MUD) hematopoietic stem cell transplantation (HSCT) is unclear, and whether there is any difference in CMV risk with 1 or 2 doses of PTCy is not well established. This study aimed to compare the incidence of CMV infection and the association between T cell recovery in patients who received PTCy-based GVHD prophylaxis and those who received non-PTCy-based GVHD prophylaxis. We conducted a retrospective study to compare the risk of CMV infection in 3 cohorts: cohort A (n=94), matched related donor (MRD)/MUD HSCT with calcineurin inhibitor-based GVHD prophylaxis; cohort B (n=103), MRD/MUD HSCT with 1 dose of PTCy, tacrolimus, and mycophenolate mofetil (MMF); and cohort C (n=28), haploidentical donor HSCT with 2 doses of PTCy, tacrolimus, and MMF. The day +100 cumulative incidence of CMV infection was 29% for cohort A, 39% for cohort B, and 61% for cohort C (P=.009), with no difference among the cohorts in the duration of viremia (P=.46). CD3+ and CD4+ T cell counts were significantly higher in cohort A at day +30 but not at days +60 and +90. Nonrelapse mortality (NRM) trended higher and relapse was significantly lower with PTCy. There was no difference in survival among the 3 cohorts. There is an increased risk of early CMV infection in patients receiving PTCy irrespective of donor type and number of PTCy doses compared with those not receiving PTCy. Strategies focusing on CMV prevention in PTCy recipients to mitigate the risk of NRM may lead to improved long-term outcomes.

Solvent-Additive Coordination Effect on Lead-Iodide Precursor for Enlarging Grain Size of Perovskite Film

A uniform and large grain perovskite helps directly enhance the device performance. Solvent additives can be introduced to obtain a uniform and large grain perovskite. To investigate the effect of solvent additives on the perovskite grain growth and photovoltaic performance, we fabricated perovskite films and solar cells prepared with solvent additives in terms of the Gutmann’s donor number (DN). The perovskite solar cell with dimethyl sulfide, which has the highest DN, exhibited a power conversion efficiency of 21.2% with a short-circuit current density of 24.0 mA/cm2, an open-circuit voltage of 1.1 V, and a fill factor of 80.2%.

Solvent effect on the Seebeck coefficient of Fe2+/Fe3+ hydrogel thermogalvanic cells

The Seebeck coefficient of Fe2+/3+ thermogalvanic cells is inversely proportional to the donor number of organic solvent additives, which cause rearrangement of the Fe2+/3+ solvent shell.

The fluctuating standard potential of lithium in organic solvents.

The standard potential of a lithium metal electrode versus the standard hydrogen electrode was calculated by constructing the thermodynamic cycle in a hypothetical electrochemical cell with a dual-phase electrolyte. It is demonstrated that the standard potential of the lithium metal electrode can fluctuate over 0.5 V in different organic solvents, and is correlated to the modified donor number by the entropy of fusion of the solvents.

Solubility of Hybrid Halide Perovskites in DMF and DMSO.

Solution methods remain the most popular means for the fabrication of hybrid halide perovskites. However, the solubility of hybrid perovskites has not yet been quantitively investigated. In this study, we present accurate solubility data for MAPbI3, FAPbI3, MAPbBr3 and FAPbBr3 in the two most widely used solvents, DMF and DMSO, and demonstrate huge differences in the solubility behavior depending on the solution compositions. By analyzing the donor numbers of the solvents and halide anions, we rationalize the differences in the solubility behavior of hybrid perovskites with various compositions, in order to take a step forward in the search for better processing conditions of hybrid perovskites for solar cells and optoelectronics.

Modulated bonding interaction in propanediol electrolytes toward stable aqueous zinc-ion batteries

Aqueous Zn-based batteries are promising energy storage technology due to their low cost and high safety. However, the solvation structure of electrolyte leads to dendrite growth, parasitic reactions, and poor low-temperature properties, limiting their practical application. Here, we report 1,2-propanediol (PG) electrolyte with a modulated solvation structure, which can suppress Zn dendrite growth and parasitic reactions. PG can break the interaction between H2O molecules and the interaction between H2O and Zn2+ due to the higher electron density of O and higher Gutmann donor number of PG than those of H2O, which increase the H-O covalent bond strength, decrease the water activity and freezing point, and change the solvation structure of Zn2+. As a result, the battery exhibits high cycling stability (Zn//Zn battery cycle over 1000 h), high reversibility (Coulombic efficiency of 98.9%), high capacity properties (specific capacity of 225 mA h g−1 at 5 A g−1, and capacity retention of 92.6% for 5000 cycles), and excellent anti-freezing properties (specific capacity of 190 mA h g−1 at −20°C over 500 cycles). This work provides a promising strategy for the development of highperformance aqueous zinc-ion batteries.