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Wyniki wyszukiwania dla: CATIONS
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Calixthioamides as ionophores for transition and heavy-metal cations
PublikacjaThere is an increasing interest in applying p-tert-butylcalix[4]arenes as sensing materials in ion-selective electrodes(ISEs). Considerable efforts were made to design calixarenes that are selective for some heavy- or transitionmetal ions to be used in ISEs for controlling and monitoring the level of such pollutants in the environment. It has been reported that introduction of softer sulfur atoms instead of oxygen atoms in calix[4]arene...
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Nature and properties of metal cations in aqueous solutions
PublikacjaOpisano i przeanalizowano budowę chemiczną, właściwości chemiczne i właściwości kinetyczne kationów metali w roztworach wodnych. Zwrócono uwagę na czynniki decydujące o właściwościach fizycznych roztworów.Wskazano na korelacje między stanami koordynacyjnymi soli i właściwościami roztworów. Zwrócono uwagę na nowe elementy chemii roztworów wodnych.
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Electron attachment to representative cations composing ionic liquids
PublikacjaUsing ab initio electronic structure methods with flexible atomic orbital basis sets, we investigated the electronic structure and stability of reduction products of selected representative cations (C+) constituting ionic liquids. We found that an electron attachment to such cations leads to the neutral radicals, whereas a subsequent attachment of another (i.e., excess) electron leads to adiabatically stable anions only in two...
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Application of nonmetallic frustrated cations in the activation of small molecules
PublikacjaThe concept of nonmetallic frustrated cations has been used in small molecule activation. The in situ generated ambiphilic phosphinoborinium cation activated phenyl isocyanate, diisopropylcarbodiimide, and acetonitrile under very mild conditions without any catalyst, yielding single-, double-, or mixed-activation products. Furthermore, the mechanisms of the reactions of the phosphinoborinium cation with small molecules were elucidated...
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Transport of alkali metal cations in poly(3,4-ethylenethiophene) films.
PublikacjaElektrochemicznie otrzymana warstwa kompozytowa złożona z poli(3,4-etyleno-dioksytiofenu) i poli(styrenosulfonianu) podczas polaryzacji ulega odwracalnemu procesowi sorpcji-desorpcji kationów z elektrolitu zewnętrznego. Transportowi jonowemu towarzyszą cząsteczki wody (rozpuszczalnika). Ilość cząsteczek wody przypadająca na jednostkowy kation metali alkalicznych została wyznaczona za pomocą metody elektrochemicznej mikrowagi...
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Ferrocenylated 1,3,5-triphenylbenzenes for the electrochemical detection of various cations or anions
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Optical Spectroscopic Studies of Tetrahydrofuran Fragmentation Induced by Collisions with Dihydrogen Cations
PublikacjaCollisions of dihydrogen cations with tetrahydrofuran molecules have been studied. Luminescence spectra and the emission functions of the excited products at projectile energies ranging from 8 to 1000 eV have been measured using collision-induced emission spectroscopy. The recorded spectra are dominated by the atomic lines of the hydrogen Balmer series, whose intensities decrease more quickly than derived by the quantum-theoretical...
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Calix[4]arene-Thioamides as Ionophores for Transition and Heavy Metal cations
PublikacjaCalix[4]arene derivatives play an important role as sensing materials in Ion Selective Electrodes(ISEs). Nowadays a high impact is put to control in natural waters the level of toxic heavy metals, like Pb ,Cd, Hg or Cu which may cause the great risk to human health. Our goal was to design and to synthesize ligands possessing ability to bind transition and heavy metal cations. The synthesis, crystal structures,extractive and ionophoric...
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Phosphinoborenium cations stabilized by N-heterocyclic carbenes: synthesis, structure, and reactivity
PublikacjaPhosphinoborenium cations stabilized by N-heterocyclic carbenes (NHCs) were synthesized via the reaction of bromo(phosphino)boranes with NHCs. Their structures were investigated by heteronuclear magnetic resonance spectroscopy, X-ray diffraction, and density functional theory calculations. They possess a planar trigonal boron center directly bonded with the pyramidal phosphanyl group (PR2) and can be treated as cationic phosphinoboranes....
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Possible Formation of H3O+ Cations Due to Aluminum Fluoride Interactions with Water
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Calix[4]arene-Thioamides as Ionophores for Transition and Heavy Metal Cations.
PublikacjaPochodne kaliks[4]arenów odgrywają ważną rolę jako materiał aktywny w membranowych elektrodach jonoselektywnych. Obecnie duży nacisk kładzie się na kontrolę stężeń kationów metali ciężkich, takich jak Pb, Cd, Hg, Cu w wodach naturalnych. Naszym zadaniem było zaprojektować i zsyntezować ligandy, które wykazują zdolność do wiązania kationów metali ciężkich i przejściowych. Synteza, struktury krystaliczne, ekstrakcja i właściwości...
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Studies of complexation of metal cations by tris(3,6-dioxaheptyl)amine in solution
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Collision-induced luminescence spectra of pyridine bombarded by 1000 eV He+ cations
PublikacjaHere we show collision-induced luminescence spectra measured for collisions of the He+cations with thearomatic six-membered ring of the pyridine molecule (C5H5N). Distinct emission bands due to the CH(A2Δ→X2Πr;B2Σ+→X2Πr;C2Σ+→X2Πr), CN(B2Σ+→X2Σ+), C2(d3Πg→a3Πu), and NH(A3Π→X3Σ−) transitions, aswell as atomic H, He, and C lines have been observed. Apart from the He atoms, all the emitters arise from thefragmentation of the pyridine...
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Chromatographic behaviour of ionic liquid cations in view of quantitative structure-retention relationship
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Determination of stability constants of complexes of selected amide ionophores with alkali metal cations
PublikacjaPodano właściwości kompleksujące jony litowców czterech jonoforów typu amidów. Wyznaczono wartości stałych kompleksów z jonów Li+, Na+, K+ metodą potencjometryczną z zastosowaniem elektrod jonoselektywnych stosując dwie różne procedury: 1) stosując jako kation referencyjny TMA+, 2) stosując chromofor kompleksujący H+.
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Volumetric properties of tetraalkylammonium cations in N,N-dimethylformamide and N,N-dimethylacetamide
PublikacjaPraca dotyczy granicznych molowych objętości i ściśliwości adiabatycznych soli tetraalkiloamoniowych w N,N-dimetyloformamidzie i N,N-dimetyloacetamidzie. W pracy zostały przedstawione zależności granicznych molowych objętości kationów tetraalkiloamoniowych od temperatury oraz długości łańcucha alkilowego. Dodatkowo pokazano, że graniczne pozorne objętości molowe jonów tetraalkiloamoniowych tworzą taką samą sekwencję jak graniczne...
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Solvation of multivalent cations in methanol - apparent molar volumes, expansibilities, and isentropic compressibilities
PublikacjaWyznaczono gęstości roztworów trifluorometanosulfonianów galu, itru, lantanu, gadolinu i lutetu w metanolu w zakresie temperatur (283.15 to 313.15) K. Zmierzono prędkości dźwięku dla tych układów w temperaturze T = 298.15 K. Z uzyskanych danych wyznaczono standardowe cząstkowe objętości molowe i ich pochodne temperaturowe oraz standardowe cząstkowe molowe ściśliwości adiabatyczne badanych jonów. Wyniki omówiono stosując klasyczny...
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Studies of the complex formation between some proton sponges and Cu(II) cations
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Green porous benzamide-like nanomembranes for hazardous cations detection, separation, and concentration adjustment
PublikacjaGreen biomaterials play a crucial role in the diagnosis and treatment of diseases as well as health-related problem-solving. Typically, biocompatibility, biodegradability, and mechanical strength are requirements centered on biomaterial engineering. However, in-hospital therapeutics require an elaborated synthesis of hybrid and complex nanomaterials capable of mimicking cellular behavior. Accumulation of hazardous cations like...
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Influence of alkali metal cations on the photoactivity of crystalline and exfoliated amorphous WO3 – photointercalation phenomenon
PublikacjaIn order to investigate the effect of photointercalation on photoelectrochemical properties, two types of WO3-based photoanodes, bulk and exfoliated have been prepared and investigated. An aqueous exfoliation method is introduced for the simple fabrication of amorphous and hydrated WO3 nanomaterial using commercial bulk WO3 precursor. The comparison of obtained material with bulk WO3 was performed using Raman, UV–vis, and XPS as...
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Non-ergodic fragmentation upon collision-induced activation of cysteine–water cluster cations
PublikacjaCysteine–water cluster cations Cys(H2O)3,6 + and Cys(H2O)3,6H+ are assembled in He droplets and probed by tandem mass spectrometry with collision-induced activation. Benchmark experimental data for this biologically important system are complemented with theory to elucidate the details of the collisioninduced activation process. Experimental energy thresholds for successive release of water are compared to water dissociation energies...
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Quantitative structure–retention relationships of ionic liquid cations in characterization of stationary phases for HPLC
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Apparent molar volumes of multicharged cations in dimethyl sulfoxide solu-tions at 25 C
PublikacjaWyznaczono gęstości oraz pozorne objętości molowe nadchloranów żelaza(III),berylu(II) i magnezu(II), azotanu srebra, nadchloranu i azotanu tetraetylo-amoniowego oraz nadchloranu i tetrafenyloboranu tetrabutyloamoniowego w roztworach w DMSO. Dokonano rozdziału granicznych wartości na udziały jonowe. Przedstawiono i przeanalizowano zmienności cząstkowe molowych objętości kationów metali solwatowanych DMSO.
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Preparation of DNA films for studies under vacuum conditions. The influence of cations in buffer solutions
PublikacjaBadania zostały przeprowadzone w celu określenia optymalnych warunków wymaganych do przygotowania jednolitych filmów superskręconego plazmidowego DNA do wykorzystania w doświadczeniach napromieniowania w warunkach wysokiej próżni. Badania pokazują, że znaczne szkody w DNA powstają w wyniku odpompowywania filmów DNA z roztworów zawierających jedynie czysta wodę.
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Charge Transfer, Complexes Formation and Furan Fragmentation Induced by Collisions with Low-Energy Helium Cations
PublikacjaThe present work focuses on unraveling the collisional processes leading to the fragmentation of the gas-phase furan molecules under the He+ and He2+ cations impact in the energy range 5–2000 eV. The presence of different mechanisms was identified by the analysis of the optical fragmentation spectra measured using the collision-induced emission spectroscopy (CIES) in conjunction with the ab initio calculations. The measurements of...
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Determination of LFER descriptors of 30 cations of ionic lquids - progress in understanding their molercular interaction potentials
PublikacjaW celu zrozumienia interakcji molekularnych trzydziestu kationów cieczy jonowych, zastosowano powszechnie znaną koncepcję liniowej zależności energii swobodnej (LFER). Deskryptory LFER dla nadmiarowej refrakcji molowej i objętości molowej, zostały obliczone in silico, natomiast kwasowość i zasadowość wiązań wodorowych, i polaryzowalność/dipoloarność kationów cieczy jonowych zostały oznaczone eksperymentalnie za pomocą wysokosprawnej...
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Hydrogen migration observed in fragmentation of the pyridine molecules in collisions with the H+, H2+, He+and He++cations
PublikacjaThe hydrogen atom migration preceding fragmentation of the pyridine molecules by the H+, H2+, He+ and He++ collisions has been investigated in the 5-2000 eV energy range. The pyridine molecule structure is lacking of the NH group, thus formation of the NH radicals is an evidence of the H atom relocation prior to the cation-induced fragmentation. The NH(A3Π) fragmentation yields measured by detecting its A3Π→X3Σ− fluorescence show...
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Disaggregation of a sumanene-containing fluorescent probe towards highly sensitive and specific detection of caesium cations
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FTIR and NMR studies of bis(oxaalkyl) sulphates(IV) and their complexes with proton and some metal cations
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The reaction heats and PM5 semiempirical studies of complexes formed between silicon podand and monovalent cations
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The reaction heats and PM5 semiempirical studies of complexes formed between silicon podand and Li+ cations
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Molecular dynamics simulations of the affinity of chitin and chitosan for collagen: the effect of pH and the presence of sodium and calcium cations
PublikacjaChitosan and chitin are promising biopolymers used in many areas including biomedical applications, such as tissue engineering and viscosupplementation. Chitosan shares similar properties with hyaluronan, a natural component of synovial fluid, making it a good candidate for joint disease treatment. The structural and energetic consequences of intermolecular interactions are crucial for understanding the biolubrication phenomenon...
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Apparent Molar Volumes and Expansivities of Ionic Liquids Based on N-Alkyl-N-methylmorpholinium Cations in Acetonitrile
PublikacjaDensities of some acetonitrile solutions of ionic liquids based on N-alkyl-N-methyl-morpholinium cations, N-ethyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-methyl-N-octylmorpholinium bis(trifluoromethanesulfonyl)imide and N-decyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide were measured at T = (298.15− 318.15) K and at atmospheric pressure....
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Solvation and partial molar volumes of some transition metal cations in N,N-dimethylacetamide, triethylphosphate and acetonitrile.
PublikacjaW oparciu o precyzyjne pomiary gęstości roztworów nadchloranów metali przejściowych szeregu Mn(II)-Zn(II) w DMA, TEP i AN wyznaczono pozorne molowe oraz graniczne wartości cząstkowych molowych objętości sole w temperaturach 293, 298 i 303,15 K. Wyznaczone wartości rozdzielono na udziały jonowe. Przeanalizowano czynniki decydujące o wielkości cząstkowych molowych objętości solwatowanych kationów.
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PHOTON LUMINESCENCE STUDIES OF TETRAHYDROFURAN FOLLOWING TRIHYDROGEN CATIONS IMPACT IN THE 20–1000 EV ENERGY RANGE
PublikacjaPhoton emission arising during tetrahydrofuran (C4H8O, THF) fragmentation initiated by H3 + ion impact has been studied experimentally. Luminescence fragmentation spectra and the relative emission cross-sections of the excited fragments have been measured using collision-induced emission spectroscopy in the 20–1000 eV energy range. The main features in the spectra are the H Balmer series lines, whose intensities decrease with increasing...
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O-substituted tetrahydroxamate derivatives of p-tert-butylcalix[4]arene as receptors for transition and heavy metal cations
PublikacjaTetrasubstituted O-hydroxamate derivatives of p-tert-butylcalix[4]arene were applied as active materials in ion-selective membrane electrodes and were tested towards Pb-selectivity. The electrodes gave near-Nernstian characteristics for Pb2+ cations. The selectivity coefficients were determined. The influence of plasticizer on the electrode behaviour was studied. The dependence of the chemical structure on selectivity coefficients...
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Volumes of N,N-dimethylacetamide solvated metal cations. Variation within the manganese(II) to zinc(II) series
PublikacjaDensities and apparent molar volumes for Mn(ClO4)2,Co(ClO4)2 , Ni(ClO4)2,Cu(ClO4)2 , and Zn(ClO4)2 in N, N -dimethylacetamide (DMA) solutions at T = 298.15 K are reported. Densities and apparent molar volumes of tetrabutylammonium tetraphenylborate...
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Solvation of ionic liquids based on N-methyl-N-alkyl morpholinium cations in dimethylsulfoxide – volumetric and compressibility studies
PublikacjaThe density and sound velocity of the solutions of ionic liquids based on N-alkyl-N-methyl-morpholinium cations, N-ethyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-methyl-N-octyl-morpholinium bis(trifluoromethanesulfonyl)imide and N-decyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide in dimethylsulfoxide were measured at T = (298.15 to 318.15)...
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Cations of amino acid alkyl esters conjugated with an anion from the group of NSAIDs – As tunable pharmaceutical active ionic liquids
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Bifunctional sulfur-silicon podands as new nucleophilic ionophores in acyl transfer reactions. Influence of monovalent cations on the reaction kinetics
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Interaction of Ionomers and Polyelectrolytes with Divalent Transition Metal Cations (Cu2+ and VO2+): A Study by Electron Spin Resonance (ESR) Spectroscopy and Viscosimetry
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Synthesis of π-extended and bowl-shaped sumanene–ferrocene conjugates and their application in highly selective and sensitive cesium cations electrochemical sensors
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Results of the effect of mixtures of ketoprofen with three cations on the germination of Sorghum bicolor (sorghum) seeds
Dane BadawczeThe research data includes an attempt to verify whether the addition of cations (sodium, ammonium and potassium) at levels found in the environment would affect the toxicity of pharmaceuticals to Sorghum Bicolor grain. Ion concentrations were selected based on studies of water samples collected in water bodies receiving wastewater from wastewater treatment...
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Transformation of polyvinyl chloride (PVC) into a versatile and efficient adsorbent of Cu(II) cations and Cr(VI) anions through hydrothermal treatment and sulfonation
PublikacjaThe reuse of waste polyvinyl chloride (PVC) has drawn much attention as it can reduce plastic waste and associated pollution, and provide valuable raw materials and products. In this study, sulfonated PVC-derived hydrochar (HS-PVC) was synthesized by two-stage hydrothermal treatment (HT) and sulfonation, and shown to be a versatile adsorbent. The reoval of Cu(II) cations and Cr(VI) anions using HS-PVC reached 81.2 ± 1.6% and 60.3...
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Synthesis, characterization and Luminescent Properties of New Coordination Polymers Based on p-tert Butylcalix[4]arene-tetracarboxylic acid and Lanthanine cations
PublikacjaA series of new coordination polymers based on p-tert-butylcalix[4]arene-tetracarboxylic acid with Eu3+, Tb3+wrer prepared by hydro and solvothermal methods. the obtained solid compounds were characterized by infrared and luminescence spectroscopy, powder X-ray diffraction, scianning electron microscopy and thermogravimetric anylisis. The infrared curves and the x-ray diffraction patterns indicate that the same crystalline structure...
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The antagonistic role of chaotropic hexafluorophosphate anions and imidazolium cations composing ionic liquids applied as phase additives in the separation of tri-cyclic antidepressants
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Solvation of ionic liquids based on N-alkyl-N-methylmorpholinium cations in N,N-dimethylformamide and dimethyl sulfoxide – A volumetric and acoustic study
PublikacjaApparent molar volumes and molar isentropic compressibilities for N-ethyl-N-methylmorpholinium and N-decyl-N-methylmorpholinium tetrafluoroborates in N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) have been determined from density and speed of sound measurements over the temperature range T = (298.15, 303.15, 308.15, 313.15, 318.15 and 328.15) K at experimental pressure p = 0.1 MPa. This data has been used to calculate...
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Solvation of ionic liquids based on N -methyl- N -alkylmorpholinium cations in N,N -dimethylformamide and N,N -dimethylacetamide – Volumetric and compressibility studies
PublikacjaDensity and sound velocity of the solutions of ionic liquids based on N-alkyl-N-methyl- morpholinium cations: N-ethyl- -methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-butyl-Nmethylmorpholinium bis(trifluoromethanesulfonyl)imide, N-octyl-N-methyl -morpholinium bis(trifluor omethanesulfonyl)imide and N-decyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide in N, N-dimethylformamide and N,N-dimethylacetamide were...
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Impact of the Alkyl Side Chains of Cations and Anions on the Activity and Renaturation of Lysozyme: A Systematic Study Performed Using Six Amino‐Acid‐Based Ionic Liquids
PublikacjaThe impact of the structure of ionic liquid on the activity and renaturation of lysozyme from the hen egg white (HEWL) was investigated. A set of six ionic liquids based on morpholinium cation and N-acylated amino acids as anions were exploited. The matrix used was based on two homologous series: one with N-acetyl-L-valinate [Val] as a common anion and morpholinium cation with a different number of carbon atoms in the n-alkyl chain...
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Impact of the Alkyl Side Chains of Cations and Anions on the Activity and Renaturation of Lysozyme: A Systematic Study Performed Using Six Amino‐Acid‐Based Ionic Liquids
PublikacjaThe impact of the structure of ionic liquid on the activity and renaturation of lysozyme from the hen egg white (HEWL) was investigated. A set of six ionic liquids based on morpholinium cation and N-acylated amino acids as anions were exploited. The matrix used was based on two homologous series: one with N-acetyl-L-valinate [Val] as a common anion and morpholinium cation with a different number of...