782 results on '"Metals, Alkali"'
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2. Ecofriendly alkali metal cations diffusion improves fabrication of mixed-phase titania polymorphs on fixed substrate by chemical vapor deposition (CVD) for photocatalytic degradation of azo dye.
- Author
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Chankhunthod N, Junploy P, Suthirakun S, Ngamwongwan L, Phromma C, Ruchusartsawat N, Siyasukh A, Yanu P, Kijjanapanich P, Yimklan S, Rujiwatra A, Drummond-Brydson R, and Chimupala Y
- Subjects
- Humans, Azo Compounds, Catalysis, Cations, Lithium, Alkalies, Metals, Alkali, Cardiovascular Diseases
- Abstract
Controlling the nanoscale synthesis of semiconductor TiO
2 on a fixed substrate has fascinated the curiosity of academics for decades. Synthesis development is required to give an easy-to-control technique and parameters for TiO2 manufacture, leading to advancements in prospective applications such as photocatalysts. This study, mixed-phase TiO2 (B)/other titania thin films were synthesized on a fused quartz substrate utilizing a modified Chemical vapor depodition involving alkali-metal ions (Li+ , Na+ , and K+ ) solution pre-treatment. It was discovered that different cations promote dramatically varied phases and compositions of thin films. The films had a columnar structure with agglomerated irregular-shaped particles with a mean thickness of 800-2000 nm. Na+ ions can promote TiO2 (B) more effectively than K+ ions, however Li+ ions cannot synthesize TiO2 (B). The amounts of TiO2 (B) in thin films increase with increasing alkali metal (K+ and Na+ ) concentration. According to experimental and DFT calculations, the hypothesized TiO2 (B) production mechanism happened via the meta-stable intermediate alkaline titanate transformation caused by alkali-metal ion diffusion. The mixed phase of TiO2 (B) and anatase TiO2 on the fixed substrate (1 × 1 cm2 ) obtained from Na+ pre-treated procedures showed significant photocatalytic activity for the degradation of methylene blue. K2 Ti6 O12 , Li2 TiO3 , Rutile TiO2 , and Brookite TiO2 phase formations produced by K+ and Li+ pretreatment are low activity photocatalysts. Photocatalytic activities were more prevalent in NaOH pre-treated samples (59.1% dye degradation) than in LiOH and KOH pre-treated samples (49.6% and 34.2%, respectively). This revealed that our developed CVD might generate good photocatalytic thin films of mixed-phase TiO2 (B)/anatase TiO2 on any substrate, accelerating progress in future applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)- Published
- 2023
- Full Text
- View/download PDF
3. Placental concentrations of alkali metals and their associations with neural tube defects in offspring
- Author
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Xin Pi, Di Wang, Chengrong Wang, Zhiwen Li, Linlin Wang, Wentao Yue, Chenghong Yin, Lei Jin, and Aiguo Ren
- Subjects
Fetus ,Reproductive Medicine ,Metals, Alkali ,Pregnancy ,Case-Control Studies ,Placenta ,Humans ,Infant ,Obstetrics and Gynecology ,Bayes Theorem ,Female ,Neural Tube Defects ,Developmental Biology - Abstract
The role of alkali metals in the development of neural tube defects (NTDs) is little known. We examined the associations between placental concentrations of lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs), and the occurrence of NTDs in fetuses.408 women who had NTD-affected pregnancies and 593 women who delivered healthy infants were included. Logistic regression, weight quantile sum regression (WQSR), and Bayesian kernel machine regression (BKMR) were applied to assess whether these metals are associated with the occurrence of NTDs.Cs showed an inverse association with the odds of NTDs [adjusted odds ratio (aOR): 0.58, 95% confidence interval (CI): 0.36-0.91] in single-metal logistic model. Estimates did not change much in the multiple-metal logistic model. In WQSR, the WQS index was inversely associated with the odds of NTDs (aOR: 0.62, 95%CI: 0.51-0.75), in which Cs (weighted 0.45) had the highest weight. In BKMR, the odds of NTDs decreased with the levels of the five-metal mixtures. Cs was associated with decreased odds of NTDs when the remaining four metals were fixed at their 25A high concentration of Cs and Na in placental tissue was respectively associated with decreased and increased odds of NTDs. In addition, the occurrence of NTDs decreased with the levels of the five-metal mixtures.
- Published
- 2022
4. Na
- Author
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Kien X, Vo, Keisuke, Hirata, James M, Lisy, Shun-Ichi, Ishiuchi, and Masaaki, Fujii
- Subjects
Metals, Alkali ,Spectrum Analysis ,Amides ,Mass Spectrometry - Abstract
Beauvericin (Bv) is a cyclic hexadepsipeptide mycotoxin that selectively transports ions across cell membranes. Characterization of its intrinsic ion affinity has been complicated by different previous results in condensed phases and biological membranes. We report the marked specificity between alkali metal ions by Bv using experimental and computational methods. Mass spectrometry shows Bv readily binds all five alkali ions; however, the complex with Na
- Published
- 2022
5. Hydrophilic Versus Hydrophobic Coupling in the Pressure Dependence of the Chemical Potential of Alkali Metal and Halide Ions in Water
- Author
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Luca Tonti and Franca Maria Floris
- Subjects
Solutions ,Metals, Alkali ,Cations ,Materials Chemistry ,Water ,Physical and Theoretical Chemistry ,Hydrophobic and Hydrophilic Interactions ,Surfaces, Coatings and Films - Abstract
We computed the chemical potential for some alkali metal ions (K
- Published
- 2022
6. Alkali Metal- and Acid-Catalyzed Interconversion of Goniodomin A with Congeners B and C
- Author
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Constance M. Harris, Kimberly S. Reece, Urban Tillmann, Bernd Krock, Thomas M. Harris, Craig J. Tainter, Donald F. Stec, Aaron John Christian Andersen, and Thomas Ostenfeld Larsen
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Ketone ,Stereochemistry ,Pharmaceutical Science ,chemistry.chemical_element ,Molecular Dynamics Simulation ,010402 general chemistry ,Ring (chemistry) ,Cleavage (embryo) ,01 natural sciences ,Oxygen ,Catalysis ,Analytical Chemistry ,Polyketide ,chemistry.chemical_compound ,Drug Discovery ,Pharmacology ,chemistry.chemical_classification ,Molecular Structure ,Metals, Alkali ,010405 organic chemistry ,Organic Chemistry ,Alkali metal ,0104 chemical sciences ,Complementary and alternative medicine ,chemistry ,Pyran ,Dinoflagellida ,Molecular Medicine ,Macrolides ,Nonane ,Acids ,Ethers - Abstract
Goniodomin A (GDA, 1) is a phycotoxin produced by at least four species of Alexandrium dinoflagellates that are found globally in brackish estuaries and lagoons. It is a linear polyketide with six oxygen heterocyclic rings that is cyclized into a macrocyclic structure via lactone formation. Two of the oxygen heterocycles in 1 comprise a spiro-bis-pyran, whereas goniodomin B (GDB) contains a 2,7-dioxabicyclo[3.3.1]nonane ring system fused to a pyran. When H2O is present, 1 undergoes facile conversion to isomer GDB and to an α,β-unsaturated ketone, goniodomin C (GDC, 7). GDB and GDC can be formed from GDA by cleavage of the spiro-bis-pyran ring system. GDA, but not GDB or GDC, forms a crown ether-type complex with K+. Equilibration of GDA with GDB and GDC is observed in the presence of H+ and of Na+, but the equilibrated mixtures revert to GDA upon addition of K+. Structural differences have been found between the K+ and Na+ complexes. The association of GDA with K+ is strong, while that with Na+ is weak. The K+ complex has a compact, well-defined structure, whereas Na+ complexes are an ill-defined mixture of species. Analyses of in vitro A. monilatum and A. hiranoi cultures indicate that only GDA is present in the cells; GDB and GDC appear to be postharvest transformation products.
- Published
- 2021
7. Phosphors Ba 2 LaTaO 6 :Mn 4+ and its alkali metal charge compensation for plant growth illumination.
- Author
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Li F, Ye Y, Cui R, Zhang J, Xu C, Xu H, Zhang G, and Deng C
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- Chlorophyll A, Luminescence, Ions, Lighting, Metals, Alkali
- Abstract
A series of Mn
4+ -doped and Mn4+ ,K+ -co-doped Ba2 LaTaO6 (BLT) double-perovskite phosphors was synthesized using a high-temperature solid-state reaction. The phase purity and luminescence properties were also studied. The optimum doping concentration of Mn4+ and K+ was obtained by investigating the photoluminescence excitation spectra and photoluminescence emission spectra. The comparison of BLT:Mn4+ phosphors with and without K+ ions shows that the photoluminescence intensity of K+ -doped phosphors was greatly enhanced. This is because there was a charge difference when Mn4+ ions were doped with Ta5+ ions in BLT. Mn4+ -K+ ion pairs were formed after doping K+ ions, which hinders the nonradiative energy transfer between Mn4+ ions. Therefore, the luminescence intensity, quantum yield, and thermal stability of phosphors were enhanced. The electroluminescence spectra of BLT:Mn4+ and BLT:Mn4+ ,K+ were measured. The spectra showed that the light emitted from the phosphors corresponded well with chlorophyll a and phytochrome PR . The results show that the BLT:Mn4+ ,K+ phosphors had good luminescence properties and application prospects and are ideal materials for plant-illuminated red phosphors., (© 2023 John Wiley & Sons Ltd.)- Published
- 2023
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8. Gas-phase thermochemistry of noncovalent ligand-alkali metal ion clusters: An impact of low frequencies.
- Author
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Otlyotov AA and Minenkov Y
- Subjects
- Ligands, Thermodynamics, Entropy, Metals, Alkali
- Abstract
The experimental gas-phase thermochemistry of reactions: M
+ (S)n-1 + S → M+ (S)n and M+ + nS→ M+ (S)n , where M is an alkali metal and S is acetonitrile/ammonia, is reproduced. Three approximations are tested: (1) scaled rigid-rotor-harmonic-oscillator (sRRHO); (2) the sRRHO(100) identical to (1), but with all vibrational frequencies smaller than 100 cm-1 replaced with 100 cm-1 ; (3) Grimme's modified scaled RRHO (msRRHO) (Grimme, Chem. Eur. J., 2012, 18, 9955-9964). The msRRHO approach provides the most accurate reaction entropies with the mean unsigned error (MUE) below 5.5 cal mol-1 K-1 followed by sRRHO(100) and sRRHO with MUEs of 7.2 and 16.9 cal mol-1 K-1 . For the first time, we propose using the msRRHO scheme to calculate the enthalpy contribution that is further utilized to arrive at reaction Gibbs free energies (∆Gr ) ensuring the internal consistency. The final ∆Gr MUEs for msRRHO, sRRHO(100) and sRRHO schemes are 1.2, 3.6 and 3.1 kcal mol-1 ., (© 2023 Wiley Periodicals LLC.)- Published
- 2023
- Full Text
- View/download PDF
9. A bottom-up approach to the ion recognition mechanism of K
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Yukina, Suzuki, Keisuke, Hirata, James M, Lisy, Shun-Ichi, Ishiuchi, and Masaaki, Fujii
- Subjects
Ions ,Coordination Complexes ,Metals, Alkali ,Lasers ,Spectrum Analysis ,Water ,Alkalies ,Peptides - Abstract
K
- Published
- 2022
10. Selective Potassium Chloride Recognition, Sensing, Extraction, and Transport Using a Chalcogen-Bonding Heteroditopic Receptor
- Author
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Andrew Docker, Igor Marques, Heike Kuhn, Zongyao Zhang, Vítor Félix, and Paul D. Beer
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Anions ,Colloid and Surface Chemistry ,Chlorides ,Metals, Alkali ,Potassium chloride ,Cations ,Chalcogens ,General Chemistry ,Biochemistry ,Catalysis ,Potassium Chloride - Abstract
Chalcogen bonding (ChB) is rapidly rising to prominence in supramolecular chemistry as a powerful sigma (σ)-hole-based noncovalent interaction, especially for applications in the field of molecular recognition. Recent studies have demonstrated ChB donor strength and potency to be remarkably sensitive to local electronic environments, including redox-switchable on/off anion binding and sensing capability. Influencing the unique electronic and geometric environment sensitivity of ChB interactions through simultaneous cobound metal cation recognition, herein, we present the first potassium chloride-selective heteroditopic ion-pair receptor. The direct conjugation of benzo-15-crown-5 ether (B15C5) appendages to Te centers in a bis-tellurotriazole framework facilitates alkali metal halide (MX) ion-pair binding through the formation of a cofacial intramolecular bis-B15C5 M+ (M+ = K+, Rb+, Cs+) sandwich complex and bidentate ChB···X- formation. Extensive quantitative 1H NMR ion-pair affinity titration experiments, solid-liquid and liquid-liquid extraction, and U-tube transport studies all demonstrate unprecedented KCl selectivity over all other group 1 metal chlorides. It is demonstrated that the origin of the receptor's ion-pair binding cooperativity and KCl selectivity arises from an electronic polarization of the ChB donors induced by the cobound alkali metal cation. Importantly, the magnitude of this switch on Te-centered electrophilicity, and therefore anion-binding affinity, is shown to correlate with the inherent Lewis acidity of the alkali metal cation. Extensive computational DFT investigations corroborated the experimental alkali metal cation-anion ion-pair binding observations for halides and oxoanions. published
- Published
- 2022
11. From BN‐Naphthalenes to Benzoborole Dianions
- Author
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Lulu Guo, Jianfeng Li, Dezhao Zhu, and Chunming Cui
- Subjects
chemistry.chemical_classification ,Lithium borate ,Metals, Alkali ,010405 organic chemistry ,Organic Chemistry ,Salt (chemistry) ,chemistry.chemical_element ,Protonation ,General Chemistry ,Lithium ,Naphthalenes ,010402 general chemistry ,Alkali metal ,01 natural sciences ,Medicinal chemistry ,Catalysis ,0104 chemical sciences ,Dilithium ,chemistry.chemical_compound ,chemistry ,Yield (chemistry) ,Borole - Abstract
The synthesis of benzoborole dianions by alkali metal reduction of BN-naphthalene derivatives via a ring-contraction strategy has been developed. Reduction of 1-alkynyl 2,1-benzazaborine 1 a in Et2 O led to the elimination of alkynyllithium with the formation of 1-amino-1-benzoborole trilithium salt 2 a, whereas reduction of 1-phenyl 2,1-benzazaborine 1 c in THF yielded 1-phenyl-1-benzoborole dilithium salt 2 c with the elimination of ArNHLi. The trilithium and dilithium salts 2 a and 2 c have been fully characterized. Treatment of trilithium salt 2 a with Et3 NHCl led to the selective protonation of the amino lithium to afford the dilithium salt 2 aH, which could be cleanly oxidized to 1-amino-1-benzoborole 3 in an excellent yield. Reaction of 1-phenyl-1-benzoborole dilithium salt 2 c with MeI yielded the lithium borate 4 c, which is luminescent both in solution and in the solid state.
- Published
- 2021
12. Analysis of trace phytoavailable heavy metals in saline soil extract by one-step electroextraction coupled with in situ desorption microplasma optical emission spectrometry
- Author
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Shuang Liu, Hao Shen, Chang Gao, Jin-Hui Liu, Yong-Liang Yu, and Jian-Hua Wang
- Subjects
Metals, Alkali ,Spectrum Analysis ,Biochemistry ,Analytical Chemistry ,Trace Elements ,Soil ,Lead ,Charcoal ,Metals, Heavy ,Environmental Chemistry ,Soil Pollutants ,Spectroscopy ,Cadmium ,Environmental Monitoring - Abstract
On-site and sensitive analysis of phytoavailable heavy metals is the key to fast evaluate the pollution incidents, while the development of convenient and efficient sample introduction approaches against matrix interference is crucial to improve the performances of field-deployable instruments. Herein, trace phytoavailable heavy metals in soil are first extracted by 0.1 M NaNO
- Published
- 2022
13. Potassium Binding Interactions with Aliphatic Amino Acids: Thermodynamic and Entropic Effects Analyzed via a Guided Ion Beam and Computational Study
- Author
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Roland M. Jones, Taylor Nilsson, Samantha Walker, and P. B. Armentrout
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Structural Biology ,Metals, Alkali ,Cations ,Entropy ,Fatty Acids ,Potassium ,Thermodynamics ,Amino Acids ,Spectroscopy - Abstract
Noncovalent interactions between alkali metals and amino acids are critical for many biological processes, especially for proper function of protein ion channels; however, many precise binding affinities between alkali metals and amino acids still need to be measured. This study addresses this need by using threshold collision-induced dissociation with a guided ion beam tandem mass spectrometer to measure binding affinities between potassium cations and the aliphatic amino acids: Gly, Ala, hAla, Val, Leu, and Ile. These measurements are supplemented by theoretical calculations and include commentary on effects of enthalpy, entropy, and structural preference. Notably, all levels of theory indicate that the lowest-lying isomers at 298 K have K
- Published
- 2022
14. Thermally and Optically Activated Migration of Charge Carriers in Alkali Metal Sesquioxides
- Author
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Matthias Adlung, Matej Komelj, Claudia Wickleder, and Martin Jansen
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Electron Transport ,Light ,Metals, Alkali ,Superoxides ,Spectrum Analysis ,Physical and Theoretical Chemistry ,Atomic and Molecular Physics, and Optics - Abstract
The alkali metal sesquioxides A
- Published
- 2022
15. Interaction of Alkali Ions with Flavins: Infrared and Optical Spectra of Metal–Riboflavin Complexes
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David Müller and Otto Dopfer
- Subjects
Ions ,Alkali ions ,Spectrophotometry, Infrared ,010304 chemical physics ,Metals, Alkali ,Chemistry ,Infrared ,Riboflavin ,Flavin group ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Optical spectra ,0104 chemical sciences ,Catalysis ,Metal ,visual_art ,0103 physical sciences ,visual_art.visual_art_medium ,heterocyclic compounds ,Physical and Theoretical Chemistry ,human activities ,Density Functional Theory - Abstract
Flavin compounds are of great interest in biochemistry because of their diverse functions in catalytic and photochemical processes. The intrinsic optical properties of flavins depend sensitively on their environment such as complexation with metal ions. Herein, we characterize the interaction of alkali metal ions (M
- Published
- 2021
16. Effect of Feed Water pH on the Partitioning of Alkali Metal Salts from Aqueous Phase into the Polyamide Active Layers of Reverse Osmosis Membranes
- Author
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Orlando Coronell, Kasia Grzebyk, Riley Vickers, Mikayla D. Armstrong, and Jingbo Wang
- Subjects
Osmosis ,Materials science ,Metals, Alkali ,Aqueous two-phase system ,Water ,Membranes, Artificial ,General Chemistry ,Quartz crystal microbalance ,Hydrogen-Ion Concentration ,010501 environmental sciences ,Permeation ,01 natural sciences ,Article ,Water Purification ,Partition coefficient ,Nylons ,Membrane ,Chemical engineering ,Thin-film composite membrane ,Polyamide ,Environmental Chemistry ,Salts ,Reverse osmosis ,0105 earth and related environmental sciences - Abstract
The partitioning of solutes into the polyamide active layers of reverse osmosis (RO) membranes is a key membrane property determining solute permeation. Quantification of partition coefficients and their dependence on feed water pH would contribute to the development of predictive transport models of contaminant transport through RO membranes; however, neither solute partitioning nor the effect of feed solution pH on partitioning has been thoroughly characterized in the literature. Accordingly, we characterized the partitioning of all chloride salts of alkali metals (CsCl, RbCl, KCl, NaCl, and LiCl) from the aqueous phase into the polyamide active layers of five polyamide RO membranes, including one prepared in-house and four commercial membranes. We evaluated the effect of pH on the partitioning of alkali metal salts and whether the effect of pH on salt partitioning and rejection is consistent with Donnan theory predictions. Results showed that, for all membranes, the partition coefficients of all salts were less than one and did not differ substantially among RO membranes. Results also indicated that, for all membranes tested, Donnan theory provided an appropriate theoretical framework to estimate the effect of pH on salt partitioning (evaluated for all chloride salts of alkali metals) and salt rejection (evaluated for NaCl). Thus, we conclude that changes in salt rejection resulting from feed solution pH are primarily driven by changes in salt partitioning with comparatively small changes in salt diffusion coefficients.
- Published
- 2021
17. Differentiation of tetracyclines and their 4-epimers by mass spectrometry of the alkali metal adduct ions
- Author
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Peixi Zhu, Dandan Chen, Kezhi Jiang, Siqi Zhu, Weike Su, Ann Van Schepdael, and Erwin Adams
- Subjects
Ions ,Spectrometry, Mass, Electrospray Ionization ,Tetracyclines ,Metals, Alkali ,Doxycycline ,Sodium ,Potassium ,Lithium ,Anti-Bacterial Agents ,Analytical Chemistry - Abstract
Tetracyclines (TCs) are a family of broad-spectrum antibiotics. During the manufacturing process or storage, epimerization of tetracyclines could occur, leading to 4-epimers which are nearly inactive. From an analytical point of view, isomers are often difficult to distinguish. Previously, four pairs of TCs (oxytetracycline, tetracycline, doxycycline, chlortetracycline and their respective 4-epimers) were differentiated by mass spectrometry (MS) through protonated ions. However, they do not follow common rules and so it is still quite difficult to differentiate between them. In order to solve this, the four pairs were differentiated in the current study by collision induced dissociation (CID) spectra of the alkali adduct ions, including lithium, sodium and potassium. In the spectra of the sodium adducts, all studied tetracyclines showed a tendency to form [M+Na-NH
- Published
- 2023
18. Alkali /alkaline earth-based metal–organic frameworks for biomedical applications
- Author
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Peng Xinsheng, Jianqiang Liu, Chen Chen, Abhinav Kumar, Dong Liu, Gaomin Ye, and Jingzhe Lin
- Subjects
Inorganic Chemistry ,Biomedical Research ,Drug Delivery Systems ,Materials science ,Metals, Alkali ,Metals, Alkaline Earth ,Humans ,Biocompatible Materials ,Nanotechnology ,Metal-organic framework ,Alkali metal ,Metal-Organic Frameworks - Abstract
With the steady development of metal-organic framework (MOF) materials, this peculiar class of three-dimensional materials has found application prospects in a myriad of areas. The integration of different metals with various categories of ligands engendered a full gamut of frameworks, which of course are supplemented by diversified modification methods. Amongst many metal centers utilized to design and synthesize targeted MOFs, alkali/alkaline earth metal-based MOFs are gaining significant attention because these metal centers can be regarded as human endogenous metals. Numerous studies have shown that alkali/alkaline earth metal MOFs (A/A-E MOFs) tend to have better properties than other metals. This is because A/A-E MOFs offer better biocompatibility, so it is expected to be used in a broader field of biomedicine in the near future. This review mainly introduces the application of A/A-E MOF materials in drug delivery, sensing, and some materials with unique biomedical applications, and elaborates the challenges, obstacles and development of some A/A-E MOF materials in the biomedical field.
- Published
- 2021
19. Cryogenic ion spectroscopy of adenine complexes containing alkali metal cations
- Author
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Jiyoung Heo, Masaaki Fujii, Han Jun Eun, Nam Kim, Seulgi Lee, Ji Young Baek, and Shun-ich Ishiuchi
- Subjects
Aqueous solution ,Spectrophotometry, Infrared ,Metals, Alkali ,010405 organic chemistry ,Chemistry ,Adenine ,Electrospray ionization ,Photodissociation ,Water ,General Physics and Astronomy ,010402 general chemistry ,Alkali metal ,01 natural sciences ,Tautomer ,0104 chemical sciences ,Ion ,Coordination Complexes ,Physical chemistry ,Ion trap ,Physical and Theoretical Chemistry ,Spectroscopy ,Density Functional Theory - Abstract
Cryogenic ion spectroscopy was used to characterize adenine complexes containing alkali metal cations (M+A, M = Cs, Rb, K, Na, and Li) produced by electrospray ionization. The ultraviolet (UV) photodissociation spectra of the complexes stored in a cryogenic ion trap exhibited well-resolved vibronic bands near their origin bands of the S0–S1 transition. The UV-UV hole-burning and infrared ion-dip spectra showed that all the M+A ions in the ion trap were single isomers of M+A7a, where the M+ ion was not bound to canonical 9H-adenine (A9) but bound to a rare tautomer, 7H-adenine (A7). Density functional theory calculations showed lower tautomerization barriers for M+A9 than for bare A9 in aqueous solution. We suggest that M+ ions not only play a catalytic role in the tautomerization of A9 to A7 but also increase the tautomerization yield by forming stable M+A7a isomers.
- Published
- 2021
20. Resolving the Mechanism of Acoustic Plasmon Instability in Graphene Doped by Alkali Metals
- Author
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Leonardo Marušić, Ana Kalinić, Ivan Radović, Josip Jakovac, Zoran L. Mišković, and Vito Despoja
- Subjects
EELS ,acoustic plasmon ,graphene ,graphene intercalation compounds ,Metals, Alkali ,Organic Chemistry ,Physics::Optics ,General Medicine ,Acoustics ,Alkalies ,Surface Plasmon Resonance ,Catalysis ,Computer Science Applications ,Inorganic Chemistry ,plasmon ,Physics::Atomic and Molecular Clusters ,Graphite ,Physical and Theoretical Chemistry ,Molecular Biology ,Spectroscopy - Abstract
Graphene doped by alkali atoms (ACx) supports two heavily populated bands (π and σ) crossing the Fermi level, which enables the formation of two intense two-dimensional plasmons: the Dirac plasmon (DP) and the acoustic plasmon (AP). Although the mechanism of the formation of these plasmons in electrostatically biased graphene or at noble metal surfaces is well known, the mechanism of their formation in alkali-doped graphenes is still not completely understood. We shall demonstrate that two isoelectronic systems, KC8 and CsC8, support substantially different plasmonic spectra: the KC8 supports a sharp DP and a well-defined AP, while the CsC8 supports a broad DP and does not support an AP at all. We shall demonstrate that the AP in an ACx is not, as previously believed, just a consequence of the interplay of the π and σ intraband transitions, but a very subtle interplay between these transitions and the background screening, caused by the out-of-plane interband C(π)→A(σ) transitions.
- Published
- 2022
- Full Text
- View/download PDF
21. A New Extraction System Based on Isopropyl Salicylate and Trioctylphosphine Oxide for Separating Alkali Metals
- Author
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Aslan Yu. Tsivadze, Alexey A. Bezdomnikov, Vladimir E. Baulin, Liudmila I. Demina, Kirill P. Birin, Dmitriy V. Baulin, and Yuliana I. Rogacheva
- Subjects
Metals, Alkali ,Organic Chemistry ,Sodium ,Pharmaceutical Science ,lithium extraction ,isopropyl salicylate ,complex synthesis ,DFT-calculation ,FTIR spectroscopy ,Raman spectroscopy ,NMR spectroscopy ,Lithium ,Salicylates ,Analytical Chemistry ,Organophosphorus Compounds ,Chemistry (miscellaneous) ,Cations ,Drug Discovery ,Spectroscopy, Fourier Transform Infrared ,Molecular Medicine ,Physical and Theoretical Chemistry - Abstract
It was established that isopropyl salicylate can be used similarly to 1,3-diketones as a key component for a new efficient extraction system for selective separation of alkali metal cations. According to DFT modeling of complexes of isopropyl salicylate and 1,3-diketone with alkali metal cations (Li+, Na+, K+), six-membered metallacycles are formed whose stability decreases along the series Li > Na > K, which results in the observed enhanced affinity to lithium. The extraction ability of isopropyl salicylate is manifested in the presence of trioctylphosphine oxide (TOPO). The newly obtained complexes of isopropyl salicylate with alkali metal cations as well as their extracts in a mixture with TOPO are characterized by means of FT-IR, Raman, and NMR spectroscopy. The probable structure of the extracted lithium complex is presumed and the role of TOPO in the extraction process is investigated in detail. Extraction experiments showed extremely high separation coefficients for Li/Na and Li/K pairs in the extraction from a model multi-component solution.
- Published
- 2022
22. Hydrogen Bonding Phase-Transfer Catalysis with Alkali Metal Fluorides and Beyond
- Author
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Gabriele Pupo and Véronique Gouverneur
- Subjects
Fluorides ,Colloid and Surface Chemistry ,Metals, Alkali ,Hydrogen Bonding ,Salts ,General Chemistry ,Biochemistry ,Catalysis - Abstract
Phase-transfer catalysis (PTC) is one of the most powerful catalytic manifolds for asymmetric synthesis. Chiral cationic or anionic PTC strategies have enabled a variety of transformations, yet studies on the use of insoluble inorganic salts as nucleophiles for the synthesis of enantioenriched molecules have remained elusive. A long-standing challenge is the development of methods for asymmetric carbon–fluorine bond formation from readily available and cost-effective alkali metal fluorides. In this Perspective, we describe how H-bond donors can provide a solution through fluoride binding. We use examples, primarily from our own research, to discuss how hydrogen bonding interactions impact fluoride reactivity and the role of H-bond donors as phase-transfer catalysts to bring solid-phase alkali metal fluorides in solution. These studies led to hydrogen bonding phase-transfer catalysis (HB-PTC), a new concept in PTC, originally crafted for alkali metal fluorides but offering opportunities beyond enantioselective fluorination. Looking ahead, the unlimited options that one can consider to diversify the H-bond donor, the inorganic salt, and the electrophile, herald a new era in phase-transfer catalysis. Whether abundant inorganic salts of lattice energy significantly higher than those studied to date could be considered as nucleophiles, e.g., CaF2, remains an open question, with solutions that may be found through synergistic PTC catalysis or beyond PTC.
- Published
- 2022
23. Like Cures like: Detoxification Effect between Alkali Metals and Sulfur over the V
- Author
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Shangchao, Xiong, Jianjun, Chen, Hao, Liu, Xiaoping, Chen, Wenzhe, Si, Zhengjun, Gong, Yue, Peng, and Junhua, Li
- Subjects
Titanium ,Ammonia ,Metals, Alkali ,Catalysis ,Sulfur - Abstract
The V
- Published
- 2022
24. SiCO Ceramics as Storage Materials for Alkali Metals/Ions: Insights on Structure Moieties from Solid-State NMR and DFT Calculations.
- Author
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Šić E, Rohrer J, Ricohermoso EI, Albe K, Ionescu E, Riedel R, Breitzke H, Gutmann T, and Buntkowsky G
- Subjects
- Density Functional Theory, Ceramics, Ions, Polymers, Magnetic Resonance Spectroscopy, Metals, Alkali
- Abstract
Polymer-derived silicon oxycarbide ceramics (SiCO) have been considered as potential anode materials for lithium- and sodium-ion batteries. To understand their electrochemical storage behavior, detailed insights into structural sites present in SiCO are required. In this work, the study of local structures in SiCO ceramics containing different amounts of carbon is presented.
13 C and29 Si solid-state MAS NMR spectroscopy combined with DFT calculations, atomistic modeling, and EPR investigations, suggest significant changes in the local structures of SiCO ceramics even by small changes in the material composition. The provided findings on SiCO structures will contribute to the research field of polymer-derived ceramics, especially to understand electrochemical storage processes of alkali metal/ions such as Na/Na+ inside such networks in the future., (© 2023 The Authors. ChemSusChem published by Wiley-VCH GmbH.)- Published
- 2023
- Full Text
- View/download PDF
25. Effect of Alkali Metal Cations on Length and Strength of Hydrogen Bonds in DNA Base Pairs
- Author
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Marcel Swart, Tadeusz M. Krygowski, Halina Szatylowicz, Olga A. Stasyuk, Miquel Solà, Célia Fonseca Guerra, AIMMS, Theoretical Chemistry, and Ministerio de Economía y Competitividad (Espanya)
- Subjects
Hydrogen bonding ,Models, Molecular ,alkali metals ,Base pair ,02 engineering and technology ,010402 general chemistry ,Aromaticity (Chemistry) ,01 natural sciences ,Nucleobase ,Metal ,Delocalized electron ,Cations ,Metalls alcalins ,Aromaticitat (Química) ,Computer Simulation ,Physical and Theoretical Chemistry ,Bond energy ,Enllaços d'hidrogen ,Base Pairing ,Density functionals ,Funcional de densitat, Teoria del ,Metals, Alkali ,Chemistry ,Hydrogen bond ,Hydrogen Bonding ,Aromaticity ,DNA ,aromaticity ,021001 nanoscience & nanotechnology ,nucleobases ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Crystallography ,visual_art ,density functional calculations ,hydrogen bonds ,visual_art.visual_art_medium ,Thermodynamics ,0210 nano-technology ,Natural bond orbital - Abstract
For many years non-covalently bonded complexes of nucleobases have attracted considerable interest. However, there is a lack of information about the nature of hydrogen bonding between nucleobases when the bonding is affected by metal coordination to one of the nucleobases, and how the individual hydrogen bonds and aromaticity of nucleobases respond to the presence of the metal cation. Here we report a DFT computational study of nucleobase pairs interacting with alkali metal cations. The metal cations contribute to the stabilization of the base pairs to varying degrees depending on their position. The energy decomposition analysis revealed that the nature of bonding between nucleobases does not change much upon metal coordination. The effect of the cations on individual hydrogen bonds were described by changes in VDD charges on frontier atoms, H bond length, bond energy from NBO analysis, and delocalization index from QTAIM calculations. The aromaticity changes were determined by HOMA index M. Solà and O.A.S. are grateful to the Ministerio de Economía y Competitividad (MINECO) of Spain (project CTQ2017-85341-P and Juan de la Cierva formación contract FJCI‐2017‐ 32757 to O.A.S.) and the Generalitat de Catalunya (project 2017SGR39). HS and TMK thank the National Science Centre of Poland for supporting this work under the grant no. UMO2016/23/B/ST4/00082. M. Swart acknowledges MICINN/MINECO (projects CTQ2014 59212 P, CTQ2015-70851-ERC, CTQ2017-87392-P), GenCat (2014SGR1202, 2017SGR1434 and XRQTC network) and European Fund for Regional Development (FEDER, UNGI104E801). C.F.G. thanks the Netherlands Organization for Scientific Research (NWO) for financial support
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- 2020
26. Alkali Metal Cationization of Tumor-associated Antigen Peptides for Improved Dissociation and Measurement by Differential Ion Mobility-Mass Spectrometry
- Author
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Gary L. Glish, Benjamin G. Vincent, James E. Keating, Chris Chung, Paul M. Armistead, Jans F. Prins, Shengjie Chai, and Sally A. Hunsucker
- Subjects
chemistry.chemical_classification ,Spectrometry, Mass, Electrospray Ionization ,Electrospray ,Metals, Alkali ,Chemistry ,Ion-mobility spectrometry ,Peptide ,General Chemistry ,Alkali metal ,Photochemistry ,Tandem mass spectrometry ,Biochemistry ,Article ,Dissociation (chemistry) ,Ion ,Metal ,Tandem Mass Spectrometry ,Cations ,visual_art ,Ion Mobility Spectrometry ,visual_art.visual_art_medium ,Peptides - Abstract
Tandem mass spectrometry (MS/MS) is a highly sensitive and selective method for the detection of tumor-associated peptide antigens. These short, nontryptic sequences may lack basic residues, resulting in the formation of predominantly [peptide + H]+ ions in electrospray. These singly charged ions tend to undergo inefficient dissociation, leading to issues in sequence determination. Addition of alkali metal salts to the electrospray solvent can drive the formation of [peptide + H + metal]2+ ions that have enhanced dissociation characteristics relative to [peptide + H]+ ions. Both previously identified tumor-associated antigens and predicted neoantigen sequences were investigated. The previously reported rearrangement mechanism in MS/MS of sodium-cationized peptides is applied here to demonstrate complete C-terminal sequencing of tumor-associated peptide antigens. Differential ion mobility spectrometry (DIMS) is shown to selectively enrich [peptide + H + metal]2+ species by filtering out singly charged interferences at relatively low field strengths, offsetting the decrease in signal intensity associated with the use of alkali metal cations.
- Published
- 2020
27. d-Alanine–d-alanine ligase as a model for the activation of ATP-grasp enzymes by monovalent cations
- Author
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Jordan L. Pederick, Stephen Bell, John B. Bruning, and Andrew P. Thompson
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Models, Molecular ,0301 basic medicine ,Stereochemistry ,Biochemistry ,03 medical and health sciences ,Adenosine Triphosphate ,Enzyme kinetics ,Peptide Synthases ,Binding site ,Molecular Biology ,chemistry.chemical_classification ,DNA ligase ,030102 biochemistry & molecular biology ,biology ,Metals, Alkali ,Chemistry ,Thermus thermophilus ,Active site ,Cell Biology ,Cations, Monovalent ,biology.organism_classification ,D-alanine—D-alanine ligase ,Enzyme structure ,body regions ,030104 developmental biology ,Enzyme ,Biocatalysis ,Enzymology ,biology.protein - Abstract
The ATP-grasp superfamily of enzymes shares an atypical nucleotide-binding site known as the ATP-grasp fold. These enzymes are involved in many biological pathways in all domains of life. One ATP-grasp enzyme, d-alanine–d-alanine ligase (Ddl), catalyzes ATP-dependent formation of the d-alanyl–d-alanine dipeptide essential for bacterial cell wall biosynthesis and is therefore an important antibiotic drug target. Ddl is activated by the monovalent cation (MVC) K(+), but despite its clinical relevance and decades of research, how this activation occurs has not been elucidated. We demonstrate here that activating MVCs bind adjacent to the active site of Ddl from Thermus thermophilus and used a combined biochemical and structural approach to characterize MVC activation. We found that TtDdl is a type II MVC-activated enzyme, retaining activity in the absence of MVCs. However, the efficiency of TtDdl increased ∼20-fold in the presence of activating MVCs, and it was maximally activated by K(+) and Rb(+) ions. A strict dependence on ionic radius of the MVC was observed, with Li(+) and Na(+) providing little to no TtDdl activation. To understand the mechanism of MVC activation, we solved crystal structures of TtDdl representing distinct catalytic stages in complex with K(+), Rb(+), or Cs(+). Comparison of these structures with apo TtDdl revealed no evident conformational change on MVC binding. Of note, the identified MVC binding site is structurally conserved within the ATP-grasp superfamily. We propose that MVCs activate Ddl by altering the charge distribution of its active site. These findings provide insight into the catalytic mechanism of ATP-grasp enzymes.
- Published
- 2020
28. Optimized Multimetal Sensitized Phosphor for Enhanced Red Up-Conversion Luminescence by Machine Learning
- Author
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Yanxing Wang, Bi Lin, Xue Jiang, Fan Yang, and Ruichan Lv
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Luminescence ,Phosphor ,010402 general chemistry ,Machine learning ,computer.software_genre ,01 natural sciences ,Machine Learning ,Metals, Heavy ,Genetic algorithm ,Humans ,Metals, Alkali ,010405 organic chemistry ,Chemistry ,business.industry ,Optical Imaging ,General Chemistry ,General Medicine ,0104 chemical sciences ,Support vector machine ,Luminescent Measurements ,Up conversion ,Artificial intelligence ,business ,computer ,Intensity (heat transfer) - Abstract
In this research, machine learning including the genetic algorithm (GA) and support vector machine (SVM) algorithm is used to solve the "low up-conversion luminescence (UCL) intensity" problem in order to find the optimal phosphor with enhanced red UCL emission using multielement K/Li/Mn metal modulation. Compared with the first generation of phosphors, the best phosphors' fluorescence intensity occurs in the third generation optimized by the GA, with a stronger brightness (4.91-fold), a higher relative quantum yield (6.40-fold), and an enhanced tissue penetration depth (by 5 mm). The single and multiple dopants effect on the upconversion intensity of K+Li+Mn sensitizers is also studied: the intensity increases first and then decreases with the increase of Yb/Er/K+Li+Mn content, and the optimized K+Li+Mn concentration is 6.03%. In order to confirm the stability of the brightness optimization by the GA, a batch of phosphors was synthesized with the same element proportion, and the similarity of fluorescence intensity of two batches of phosphors was evaluated by the SVM algorithm with the classification accuracy index. Finally, the optimized phosphor was used for bioimaging and phosphor-LED.
- Published
- 2020
29. Charge Reduction of Membrane Proteins in Native Mass Spectrometry Using Alkali Metal Acetate Salts
- Author
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Carl Frieden, Farha Khan, Gregory T. DeKoster, John T. Petroff, Lawrence J. Chen, Jeff Abramson, Wayland W.L. Cheng, and Ailing Tong
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Detergents ,Pyruvate Kinase ,Inorganic chemistry ,Acetates ,010402 general chemistry ,Mass spectrometry ,01 natural sciences ,Article ,Mass Spectrometry ,Analytical Chemistry ,Reduction (complexity) ,Glutamate Dehydrogenase ,Animals ,Metals, Alkali ,Chemistry ,010401 analytical chemistry ,Membrane Proteins ,Charge (physics) ,Alkali metal ,0104 chemical sciences ,Solubility ,Membrane protein ,Cattle ,Salts ,Rabbits ,Oxidation-Reduction - Abstract
Native mass spectrometry paired with ion mobility (IM-MS) provides the capacity to monitor the structure of protein complexes and simultaneously assess small molecule binding to the protein. Native IM-MS typically utilizes positive mode electrospray ionization producing a distribution of multiply charged protein species. For membrane proteins, these charge states are often too high resulting in protein gas phase unfolding or loss of noncovalent interactions. In an effort to reduce the charge of membrane proteins, the utility of alkali metal salts as a charge reducing additive was explored. Low concentrations of alkali metal salts caused marked charge reduction in the membrane protein, ELIC. The charge reducing effect was only present in membrane proteins, and could not be accounted for by conformational changes in ELIC structure. Charge reduction by alkali metal salts was also detergent dependent, and was most pronounced in long PEG-based detergents such as C10E5 and C12E8. Based on these results, a mechanism was posited for alkali metal charge reduction of membrane proteins. Addition of low concentration of alkali metals may provide an advantageous approach for charge reduction of detergent solubilized membrane proteins by native MS.
- Published
- 2020
30. Infrared multiple-photon dissociation spectroscopy of cationized glycine: effects of alkali metal cation size on gas-phase conformation
- Author
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P. B. Armentrout, Brandon C. Stevenson, Maryam Ghiassee, Georgia C. Boles, Giel Berden, Jos Oomens, and Molecular Spectroscopy (HIMS, FNWI)
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Oxygen ,FELIX Molecular Structure and Dynamics ,Metals, Alkali ,Cations ,Glycine ,Molecular Conformation ,General Physics and Astronomy ,Physical and Theoretical Chemistry - Abstract
The gas-phase structures of cationized glycine (Gly), including complexes with Li+, Na+, K+, Rb+, and Cs+, are examined using infrared multiple-photon dissociation (IRMPD) spectroscopy utilizing light generated by a free electron laser, in conjunction with ab initio calculations. To identify the structures present in the experimental studies, measured IRMPD spectra are compared to spectra calculated at B3LYP/6-311+G(d,p) for the Li+, Na+, and K+ complexes and at B3LYP/def2TZVP for the Rb+ and Cs+ complexes. Single-point energy calculations were carried out at the B3LYP, B3P86, and MP2(full) levels using the 6-311+G(2d,2p) basis set for Li+, Na+, K+ and the def2TZVPP basis set for Rb+ and Cs+. The Li+ and Na+ complexes are identified as metal cation coordination to the amino nitrogen and carbonyl oxygen, [N,CO]-tt, although Na+(Gly) may have contributions from additional structures. The heavier metal cations coordinate to either the carbonyl oxygen, [CO]-cc, or the carbonyl oxygen and hydroxy oxygen, [CO,OH]-cc, with the former apparently preferred for Rb+ and Cs+ and the latter for K+. These two structures reside in a double-well potential and different levels of theory predict very different relative stabilities. Some experimental evidence is provided that MP2(full) theory provides the most accurate relative energies.
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- 2022
31. Morphotropism in fumarolic mineral-related anhydrous sulfates: novel representatives in A
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Oleg I, Siidra, Diana, Nekrasova, Olga, Blatova, Marie, Colmont, Olivier, Mentré, and Dmitri, Charkin
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Minerals ,Metals, Alkali ,Sulfates ,Russia - Abstract
The discovery of numerous endemic anhydrous sulfate minerals in fumaroles of the Tolbachik volcano (Kamchatka, Russia) has revived interest in the whole family of anhydrous sulfates. Herein is reported the crystal structure of Cs
- Published
- 2021
32. Bioremediation potential of hexavalent chromium-resistant Arthrobacter globiformis 151B: study of the uptake of cesium and other alkali ions
- Author
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Olia Rcheulishvili, Nunu Metreveli, Revaz Solomonia, Lia Tsverava, and Hoi-Ying Holman
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Microbiology (medical) ,Chromium ,Proteome ,Metals, Alkali ,Sodium ,Cesium ,Alkalies ,Rubidium ,Microbiology ,Biodegradation, Environmental ,Cations ,Radioactive Waste ,Potassium ,Arthrobacter ,Reactive Oxygen Species - Abstract
Cesium (Cs
- Published
- 2021
33. Photodestruction of Diatomic Molecular Ions: Laboratory and Astrophysical Application
- Author
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Milan S. Dimitrijević, Vladimir A. Srećković, and Ljubinko M. Ignjatović
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Pharmaceutical Science ,01 natural sciences ,Article ,Analytical Chemistry ,Ion ,lcsh:QD241-441 ,lcsh:Organic chemistry ,0103 physical sciences ,Drug Discovery ,Physics::Atomic and Molecular Clusters ,Physical and Theoretical Chemistry ,Physics::Chemical Physics ,010306 general physics ,010303 astronomy & astrophysics ,astrophysical processes ,Diatoms ,atomic and molecular data ,planetary geochemistry ,plasma diagnostics ,Metals, Alkali ,Organic Chemistry ,Photodissociation ,Astronomical Phenomena ,fungi ,diatomic molecules ,Oxides ,photodissociation ,Rotational–vibrational spectroscopy ,Plasma ,Alkali metal ,Diatomic molecule ,Wavelength ,Chemistry (miscellaneous) ,molecular spectroscopy ,planetary chemistry ,Molecular Medicine ,Thermodynamics ,Plasma diagnostics ,radiative processes ,Atomic physics ,Laboratories - Abstract
In this work, the processes of photodissociation of some diatomic molecular ions are investigated. The partial photodissociation cross-sections for the individual rovibrational states of the diatomic molecular ions, which involves alkali metals, as well as corresponding data on molecular species and molecular state characterizations, are calculated. Also, the average cross-section and the corresponding spectral absorption rate coefficients for those small molecules are presented in tabulated form as a function of wavelengths and temperatures. The presented results can be of interest for laboratory plasmas as well as for the research of chemistry of different stellar objects with various astrophysical plasmas.
- Published
- 2021
34. Sigma/pi Bonding Preferences of Solvated Alkali-Metal Cations to Ditopic Arylmethyl Anions
- Author
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Annabel Rae, Keelan M. Byrne, Scott A. Brown, Alan R. Kennedy, Tobias Krämer, Robert E. Mulvey, and Stuart D. Robertson
- Subjects
Anions ,Models, Molecular ,Metals, Alkali ,Cations ,Organic Chemistry ,QD ,General Chemistry ,Alkalies ,Catalysis - Abstract
Arylmethyl anions allow alkali-metals to bind in a σ-fashion to the lateral carbanionic centre or a π-fashion to the aryl ring or in between these extremities, with the trend towards π bonding increasing on descending group 1. Here we review known alkali metal structures of diphenylmethane, fluorene, 2-benzylpyridine and 4-benzylpyridine. Next, we synthesise Li, Na, K monomers of these diarylmethyls using polydentate donors PMDETA or Me 6TREN to remove competing oligomerizing interactions, studying the effect that two aromatic rings has on negative charge (de)localisation via NMR, X-ray crystallographic and DFT studies. Diphenylmethyl and fluorenyl anions maintain C(H)−M interactions regardless of alkali-metal, although the adjacent arene carbons engage in interactions with larger alkali-metals. Introducing a nitrogen atom into the ring (at the 2- or 4-position) encourages relocalisation of negative charge away from the deprotonated carbon and onto nitrogen. Phenyl(2-pyridyl)methyl moves from an enamide formation at one extremity (lithium) to an aza-allyl formation at the other extremity (potassium), while C- or N-coordination modes become energetically viable for Na and K phenyl(4-pyridyl)methyl complexes.
- Published
- 2021
35. Layered Double Hydroxide‐Assisted Fabrication of Prussian Blue Membranes for Precise Molecular Sieving
- Author
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Qi Bian, Mu Zhang, Yi Liu, Liangliang Liu, Yang Li, Chen Wang, and Gaohong He
- Subjects
Prussian blue ,Aqueous solution ,Materials science ,Metals, Alkali ,Metal ions in aqueous solution ,chemistry.chemical_element ,General Medicine ,General Chemistry ,Catalysis ,Metal ,Electrolytes ,chemistry.chemical_compound ,Membrane ,chemistry ,Chemical engineering ,visual_art ,Hydroxides ,visual_art.visual_art_medium ,Water splitting ,Hydroxide ,Lithium ,Particle Size ,Ferrocyanides - Abstract
Prussian Blue (PB), which was first discovered as robust blue-colored pigment in the year 1706, has shown promising prospects in disease treatment, energy conversion, water splitting, and sensing. Relying on the uniform 3.2 A-sized pore channels as well as high stability in aqueous environments, in this study, we pioneered in situ preparation of polycrystalline PB membranes to justify their dye rejection and metal ion discrimination ability in aqueous environments. Among various factors, the introduction of calcined NiFe layered double hydroxide buffer layers on porous α-Al 2 O 3 substrates was found to play a paramount role in the formation of continuous polycrystalline PB membranes, thereby leading to excellent dye rejection efficiency (>99.0%). Moreover, prepared PB membranes enabled discriminating different monovalent metal ions (e.g., Li + , Na + , and K + ) depending on their discrepancy in Stokes diameters, showing great promise for lithium extraction from smaller-sized metal ions.
- Published
- 2021
36. Preparing hierarchical porous carbon with well-developed microporosity using alkali metal-catalyzed hydrothermal carbonization for VOCs adsorption
- Author
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Guangzheng Ye, Yuqin Wang, Wenfu Zhu, Xiaohong Wang, Fan Yao, Yujun Jiao, Hairong Cheng, Haomin Huang, and Daiqi Ye
- Subjects
Environmental Engineering ,Metals, Alkali ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,Environmental Chemistry ,General Medicine ,General Chemistry ,Adsorption ,Pollution ,Porosity ,Carbon ,Catalysis - Abstract
Biomass-derived porous carbonaceous materials are efficient adsorbents for VOCs, but their traditional preparation method, pyrolysis combined with activation, suffers from high energy consumption, equipment corrosion, and low pore-making efficiency, which hinders their large-scale practical application. A novel method of alkali metal-catalyzed hydrothermal carbonization coupling with chemical activation for the preparation of microporous carbon is presented. Porous carbon with well-developed microporosity deriving from corn husk were prepared through the hydrothermal carbonization using potassium persulfate (K
- Published
- 2021
37. Bifunctional homologous alkali-metal artificial synapse with regenerative ability and mechanism imitation of voltage-gated ion channels
- Author
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Luodan Hu, Kai Liu, Kuan-Chang Chang, Heng-Jui Liu, Tzu-Peng Kuo, Pei Huang, Rui Zhang, Lei Li, Xinnan Lin, and Shengdong Zhang
- Subjects
Emulation ,Artificial neural network ,Voltage-gated ion channel ,Mechanism (biology) ,Computer science ,Metals, Alkali ,Process Chemistry and Technology ,Neurotransmission ,Alkalies ,Imitative Behavior ,Ion Channels ,Synapse ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Synapses ,Humans ,General Materials Science ,Electrical and Electronic Engineering ,Bifunctional ,Neuroscience ,Ion channel - Abstract
As a key component responsible for information processing in the brain, the development of a bionic synapse possessing digital and analog bifunctionality is vital for the hardware implementation of a neuro-system. Here, inspired by the key role of sodium and potassium in synaptic transmission, the alkali metal element lithium (Li) belonging to the same family is adopted in designing a bifunctional artificial synapse. The incorporation of Li endows the electronic devices with versatile synaptic functions. An artificial neural network based on experimental data exhibits a high performance approaching near-ideal accuracy. In addition, the regenerative ability allows synaptic functional recovery through low-frequency stimuli to be emulated, facilitating the prevention of permanent damage due to intensive neural activities and ensuring the long-term stability of the entire neural system. What is more striking for an Li-based bionic synapse is that it can not only emulate a biological synapse at a behavioral level but realize mechanism emulation based on artificial voltage-gated “ion channels”. Concurrent digital and analog features lead to versatile synaptic functions in Li-doped artificial synapses, which operate in a mode similar to the human brain with its two hemispheres excelling at processing imaginative and analytical information, respectively.
- Published
- 2021
38. Probing topology of supramolecular complexes between cyclodextrins and alkali metals by ion mobility-mass spectrometry
- Author
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Cédric, Przybylski and Véronique, Bonnet
- Subjects
Cyclodextrins ,Polymers and Plastics ,Metals, Alkali ,Ammonium Compounds ,Organic Chemistry ,Materials Chemistry ,Protons ,Mass Spectrometry - Abstract
In this study, the size and shape of supramolecular assemblies between cyclo-oligosaccharides and proton, ammonium or a series of alkali metals by electrospray coupled to trapped ion mobility-mass spectrometry (ESI-TIMS) have investigated. Native cyclodextrins (CD) were selected as models, and collision cross section (CCS) values were deducted for the main positive singly and doubly charged species. Experimental CCS values were in good agreement with those obtained from molecular modeling. Due to the high mobility resolving power and resolution, it was possible to highlight the presence of various conformers. Also, TIMS allowed to discriminate and estimate the content of various orientations from non-covalent nanotubes-based CD, involving secondary/secondary rim hydroxyl groups (head-to head), primary/secondary rim (head-to-tail) hydroxyl groups or primary/primary rim (tail-to-tail) hydroxyl groups interactions. Such results pave the way for a better knowledge of the topology of cyclo-oligosaccharides based supramolecular complexes, demonstrating that TIMS can be a particularly attractive molecular descriptor.
- Published
- 2022
39. The impact of the electric field of metal ions on the vibrations and internal hydrogen bond strength in alkali metal ion di- and triglycine complexes
- Author
-
Kathleen Nickson, Etienne Garand, and Katharina Meyer
- Subjects
Ions ,Nitrilotriacetic Acid ,Metals, Alkali ,Metals ,Sodium ,General Physics and Astronomy ,Hydrogen Bonding ,Physical and Theoretical Chemistry ,Peptides ,Vibration ,Hydrogen - Abstract
Using infrared predissociation spectroscopy of cryogenic ions, we revisit the vibrational spectra of alkali metal ion (Li+, Na+, K+) di- and triglycine complexes. We assign their most stable conformation, which involves metal ion coordination to all C=O groups and an internal NH⋯NH2 hydrogen bond in the peptide backbone. An analysis of the spectral shifts of the OH and C=O stretching vibrations across the different metal ions and peptide chain lengths shows that these are largely caused by the electric field of the metal ion, which varies in strength as a function of the square of the distance. The metal ion–peptide interaction also remotely modulates the strength of internal hydrogen bonding in the peptide backbone via the weakening of the amide C=O bond, resulting in a decrease in internal hydrogen bond strength from Li+ > Na+ > K+.
- Published
- 2022
40. Supercritical water gasification of hyperaccumulators for hydrogen production and heavy metal immobilization with alkali metal catalysts
- Author
-
Wei Su, Miaomiao Zhao, Yi Xing, Hongzhi Ma, Ping Liu, Xinyan Li, Hongshuo Zhang, Yingji Wu, and Changlei Xia
- Subjects
Metals, Alkali ,Metals, Heavy ,Sodium Hydroxide ,Water ,Alkalies ,Biochemistry ,Cadmium ,Hydrogen ,General Environmental Science - Abstract
The high moisture content and heavy metal concentration of hyperaccumulator are the main bottlenecks of resource utilization. Supercritical water gasification technology was used to convert Sedum plumbizincicola (a hyperaccumulator of Zn and Cd) into hydrogen gas and to immobilize HMs into biochar. Homogeneous alkali metal catalysts such as NaOH, Na
- Published
- 2022
41. Double Ion Trap Laser Spectroscopy of Alkali Metal Ion Complexes with a Partial Peptide of the Selectivity Filter in K
- Author
-
Yukina, Suzuki, Keisuke, Hirata, James M, Lisy, Shun-Ichi, Ishiuchi, and Masaaki, Fujii
- Subjects
Ions ,Spectrophotometry, Infrared ,Coordination Complexes ,Metals, Alkali ,Lasers ,Temperature ,Alkalies ,Peptides - Abstract
Potassium ion channels selectively permeate K
- Published
- 2021
42. The study of biological activity of mandelic acid and its alkali metal salts in wastewaters
- Author
-
Marzena Matejczyk, Włodzimierz Lewandowski, Renata Świsłocka, Monika Parcheta, and Piotr Ofman
- Subjects
chemistry.chemical_classification ,Chemistry ,Metals, Alkali ,Salt (chemistry) ,Biological activity ,Wastewater ,medicine.disease_cause ,Mandelic acid ,Alkali metal ,Biochemistry ,Metal ,chemistry.chemical_compound ,visual_art ,visual_art.visual_art_medium ,medicine ,Escherichia coli ,Mandelic Acids ,Salts ,Growth inhibition ,Antibacterial activity ,Genotoxicity ,General Environmental Science ,Nuclear chemistry - Abstract
In the present work we compared the biological activity of mandelic acid (MA) and its Li, Na, K, Rb and Cs salts. The study also investigated the effect of raw wastewaters (RW) and treated wastewaters (TW), comparable to microbial medium (MM) on the biological activity of the tested chemical compounds used in concentrations of 5; 2.5; 1.25; 0.625; 0.3125 mg/ml. In the present experiment the evaluation of the following parameters was performed: E. coli (ATCC 25922) cells viability, growth inhibition of E. coli (ATCC 25922), the inhibition of GFP protein, genotoxicity and ROS generation. Our results showed that three main factors differentiated the antibacterial activity of MA and its Li, Na, K, Rb and Cs salts: study environment (MM, RW, TW), metal forming salt of mandelic acid and concentration of tested compounds. Additionally, raw and treated wastewater, compared to microbial medium, changes the antimicrobial activity of MA and its salts in relation to the E. coli strain. We also detected that both MA and its salts affect the GFP protein and the induction of the recA promoter (genotoxicity test). The activity of the tested salts in relation to these two parameters is strictly dependent on the type of salt-forming metal and the concentration used. The analysis of ROS synthesis suggests that in the majority of the studied mandelic acid salts, oxidative stress is the dominant mechanism of cytotoxicity and genotoxicity. We also showed that both raw wastewaters (RW) and treated wastewaters (TW), compared to microbial medium (MM), change significantly the activity of MA and its salts.
- Published
- 2021
43. Alkali and Alkaline Earth Metal Complexes as Versatile Catalysts for Ring-Opening Polymerization of Cyclic Esters
- Author
-
Jayeeta Bhattacharjee, Tarun K. Panda, and Alok Sarkar
- Subjects
Lactide ,Biocompatibility ,Metals, Alkali ,General Chemical Engineering ,Polyesters ,Esters ,macromolecular substances ,General Chemistry ,Biodegradation ,Biochemistry ,Ring-opening polymerization ,Catalysis ,Polyester ,chemistry.chemical_compound ,Membrane ,Monomer ,chemistry ,Polymerization ,Coordination Complexes ,Cyclization ,Metals, Alkaline Earth ,Materials Chemistry ,Organic chemistry ,Chalcogens ,Boranes - Abstract
Biodegradable polyesters such as poly(ϵ-caprolactone) (PCL) and poly(lactic acid) (PLA) have been considered for use in several areas, such as drug delivery devices, sutures, tissue engineering, and GBR membranes, due to its bio-renewability, biodegradability, and biocompatibility. Several synthetic techniques for the preparation of polyesters have been reported in the literature, amongst which the ring-opening polymerization (ROP) of cyclic esters is the most efficient. A convenient approach to access iso-selective PLAs is polymerization of racemic lactide (rac-LA), which shows excellent stereoregularity without the need for costly chiral auxiliaries or ligands. In this personal account, we review a series of methods that have been practiced to the synthesis of biodegradable polyesters from various cyclic monomers using alkali and alkaline earth metal complexes as efficient catalysts.
- Published
- 2021
44. Drude polarizable force field for cation–π interactions of alkali and quaternary ammonium ions with aromatic amino acid side chains
- Author
-
Esam A. Orabi, Guillaume Lamoureux, and Rebecca L. Davis
- Subjects
Ions ,Tetramethylammonium ,010304 chemical physics ,Metals, Alkali ,Ab initio ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Toluene ,0104 chemical sciences ,Ion ,Quaternary Ammonium Compounds ,Amino Acids, Aromatic ,Computational Mathematics ,chemistry.chemical_compound ,Crystallography ,Molecular dynamics ,Molecular recognition ,chemistry ,Ab initio quantum chemistry methods ,0103 physical sciences ,Side chain ,Density Functional Theory - Abstract
Cation-π interactions play important roles in molecular recognition and in the stability and function of proteins. However, accurate description of the structure and energetics of cation-π interactions presents a challenge to both additive and polarizable force fields, which are rarely designed to account for the complexation of charged groups with aromatic moieties. We calibrate the Drude polarizable force field for complexes of alkali metal ions (Li+ , Na+ , K+ , Rb+ , Cs+ ), ammonium (NH4+ ), tetramethylammonium (TMA+ ), and tetraethylammonium (TEA+ ) with aromatic amino acid side chain model compounds (benzene, toluene, 4-methylphenol, 3-methylindole) using high-level ab initio quantum chemical properties of these complexes. Molecular dynamics simulations reveal that cation-π complexes of the hard and tightly coordinated Li+ and Na+ ions are not stable in water but that larger ions form stable complexes, with binding free energies ranging between -0.8 and -2.9 kcal/mol. Like in gas phase, all complexes at equilibrium adopt an "en-face" complexation mode in water. The optimized Drude polarizable model provides an accurate description of the cation-π interactions involving small ions and proteins. © 2019 Wiley Periodicals, Inc.
- Published
- 2019
45. Elemental Analysis of Human Blood Serum by Microwave Plasma—Investigation of the Matrix Effects Caused by Sodium Using Model Solutions
- Author
-
Baranyai, Edina, Tóth, Csilla Noémi, and Fábián, István
- Subjects
Models, Molecular ,Solutions ,Elemental analysis ,Metals, Alkali ,Metals, Alkaline Earth ,Metals, Heavy ,Sodium ,MP-AES ,Humans ,Blood serum ,Microwaves ,Article ,Matrix effect - Abstract
Human blood is a complex sample matrix when elemental analysis is considered. In this study, the effects of Na, a natural component of serum samples, was investigated in the quantitative determination of Ca, K, Mg, Cu, Zn, and Fe by microwave plasma atomic emission spectrometry. The robustness of the microwave plasma was tested by evaluating MgII 280.271 nm/MgI 285.213 nm by varying two adjustable operating parameters, the read time, and the nebulizer pressure. The read time has no influence on the robustness while the MgII/MgI ratio decreased when the nebulizer pressure was increased during the analysis. The threshold concentrations of the interfering Na were determined at the analytical lines used for the measurement of other elements. The matrix effect of the commercially available microwave plasma was studied by a series of model experiments with human blood. The increasing concentration of Na in the matrix within the normal ranges reported for blood serum increased the intensities of the measured atomic lines. According to a factorial design—where two applied factors were the concentration of Na matrix and the measured elements as well as their levels were considered as factorial points—it was found that the Na concentration in a serum sample after acid digestion and 10 times dilution affected the intensity values of the measured elements. For Ca, Cu, and Fe, a statistically significant effect was observed, while for Zn, Mg, and K, an interaction effect was also found. However, after calculating the percentage errors caused by the shift, the relative difference was observed to be quite small (
- Published
- 2019
46. Recent advances in the mechanisms of NLRP3 inflammasome activation and its inhibitors
- Author
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Houhui Song, Fushan Shi, Yang Yang, Mohammed Kouadir, and Huanan Wang
- Subjects
0301 basic medicine ,Cancer Research ,Programmed cell death ,Multiprotein complex ,Inflammasomes ,Immunology ,Disease ,Review Article ,Heterocyclic Compounds, 4 or More Rings ,Proinflammatory cytokine ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Mice ,0302 clinical medicine ,NLR Family, Pyrin Domain-Containing 3 Protein ,Nitriles ,medicine ,Animals ,Humans ,ortho-Aminobenzoates ,Calcium Signaling ,Sulfones ,lcsh:QH573-671 ,Furans ,Calcium signaling ,Sulfonamides ,integumentary system ,Chemistry ,Metals, Alkali ,lcsh:Cytology ,Thiones ,Inflammasome ,Cell Biology ,Cell biology ,Uric acid crystals ,030104 developmental biology ,Indenes ,030220 oncology & carcinogenesis ,Thiazolidines ,NLRP3 inflammasome activation ,Diterpenes, Kaurane ,Lysosomes ,Reactive Oxygen Species ,Protein Processing, Post-Translational ,medicine.drug - Abstract
The NLRP3 inflammasome is a multimeric protein complex that initiates an inflammatory form of cell death and triggers the release of proinflammatory cytokines IL-1β and IL-18. The NLRP3 inflammasome has been implicated in a wide range of diseases, including Alzheimer’s disease, Prion diseases, type 2 diabetes, and some infectious diseases. It has been found that a variety of stimuli including danger-associated molecular patterns (DAMPs, such as silica and uric acid crystals) and pathogen-associated molecular patterns (PAMPs) can activate NLRP3 inflammasome, but the specific regulatory mechanisms of NLRP3 inflammasome activation remain unclear. Understanding the mechanisms of NLRP3 activation will enable the development of its specific inhibitors to treat NLRP3-related diseases. In this review, we summarize current understanding of the regulatory mechanisms of NLRP3 inflammasome activation as well as inhibitors that specifically and directly target NLRP3.
- Published
- 2019
47. Convergent Ditopic Receptors Enhance Anion Binding upon Alkali Metal Complexation for Catalyzing the Ritter Reaction
- Author
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Sangaraiah Nagarajan, Darren W. Johnson, Lihua Yuan, Wen Feng, Jessica A. Lohrman, Lixi Chen, Xin Shen, Kang Kang, Pengchi Deng, and Kuirong Fu
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Macrocyclic Compounds ,Supramolecular chemistry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Catalysis ,Article ,Metal ,chemistry.chemical_compound ,Amide ,Physical and Theoretical Chemistry ,Anion binding ,Metals, Alkali ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Hydrogen Bonding ,Alkali metal ,Amides ,Combinatorial chemistry ,Ritter reaction ,0104 chemical sciences ,Organic reaction ,visual_art ,visual_art.visual_art_medium - Abstract
A supramolecular approach to catalyzing the Ritter reaction by utilizing enhanced anion-binding affinity in the presence of alkali metal cations was developed with ditopic hydrogen-bonded amide macrocycles. With prebound cations in the macrocycle, particularly Li(+) ion, their metal complexes exhibit greatly enhanced catalytic activities. The catalysis is switchable by removal or addition of the bound cation. The method described in this work may be generalized for use in other anion-triggered organic reactions involving heteroditopic receptors capable of ion pairing.
- Published
- 2019
48. Inorganic electrides of alkali metal doped Zn
- Author
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Saima, Khan, Mazhar Amjad, Gilani, Sajida, Munsif, Shabbir, Muhammad, Ralf, Ludwig, and Khurshid, Ayub
- Subjects
Zinc ,Metals, Alkali ,Fullerenes ,Electronics - Abstract
Finding new materials with exceptionally large nonlinear optical response is an interesting and challenging avenue for scientific research. Here, we report the alkali metal doped Zn
- Published
- 2021
49. Modeling of Solute-Solvent Interactions Using an External Electric Field—From Tautomeric Equilibrium in Nonpolar Solvents to the Dissociation of Alkali Metal Halides
- Author
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Ilya G. Shenderovich and Gleb S. Denisov
- Subjects
Models, Molecular ,Pyridines ,Pharmaceutical Science ,external electric field ,01 natural sciences ,Polarizable continuum model ,Dissociation (chemistry) ,Analytical Chemistry ,chemistry.chemical_compound ,Electricity ,reaction field ,Drug Discovery ,Physics::Chemical Physics ,Physics::Biological Physics ,Quantitative Biology::Biomolecules ,condensed matter ,010304 chemical physics ,Solutions ,Solvent ,Chemistry (miscellaneous) ,polarizable continuum model ,Thermodynamics ,Molecular Medicine ,Chloroform ,Materials science ,Cyclohexane ,ddc:540 ,dissociation ,010402 general chemistry ,Quantum chemistry ,Article ,solvent effect ,tautomerism ,lcsh:QD241-441 ,lcsh:Organic chemistry ,Cyclohexanes ,Polarizability ,Electric field ,0103 physical sciences ,Computer Simulation ,Physical and Theoretical Chemistry ,Metals, Alkali ,Organic Chemistry ,0104 chemical sciences ,Condensed Matter::Soft Condensed Matter ,chemistry ,540 Chemie ,Solvents ,Quantum Theory ,Solvent effects - Abstract
An implicit account of the solvent effect can be carried out using traditional static quantum chemistry calculations by applying an external electric field to the studied molecular system. This approach allows one to distinguish between the effects of the macroscopic reaction field of the solvent and specific solute–solvent interactions. In this study, we report on the dependence of the simulation results on the use of the polarizable continuum approximation and on the importance of the solvent effect in nonpolar solvents. The latter was demonstrated using experimental data on tautomeric equilibria between the pyridone and hydroxypyridine forms of 2,6-di-tert-butyl-4-hydroxy-pyridine in cyclohexane and chloroform.
- Published
- 2021
50. Spin tuning of electron-doped metal-phthalocyanine layers
- Subjects
Indoles ,Alkali metal doping ,Metals, Alkali ,Electrons ,Circular dichroism ,Molecular magnet ,X-Ray Absorption Spectroscopy ,Organic-based magnets ,Microscopy, Scanning Tunneling ,Magnetic characteristic ,Metals, Heavy ,Organometallic Compounds ,Alkali-metal adsorption ,Orbital magnetic moment ,Magnetic configuration ,Adsorbate-substrate - Published
- 2021
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