Cation Of Compound Research Articles

Size-Dependent Isovalent Impurity Doping for Ambipolar Control in Cu3N.

Substitutional doping, involving the replacement of a host with an aliovalent impurity ion, is widely used to attain ambipolar controllability in semiconductors, which is crucial for device application. However, its effectiveness for p-type doping is limited in monovalent cation compounds due to the lack of suitable aliovalent (i.e., zerovalent) impurities. We propose an alternative approach for p- and n-type doping, mediated by the sizes of isovalent alkali metal impurities in Cu(I)-based semiconductors, such as copper nitride with an electron concentration of ∼1015 cm-3. Doping of isovalent Li with a smaller size to interstitial positions improves n-type conductivity, and electron concentration is controllable in the range of 1015 to 1018 cm-3. In contrast, larger isovalent Cs and Rb impurities facilitate p-type conversion, resulting in a hole concentration controllability of 1014 to 1017 cm-3. First-principles calculations indicate that Li is placed as an interstitial impurity acting as a shallow donor in conjunction with the formation of a neutral impurity on Cu defects. As the impurity size increases beyond the capacity of the vacant space, the formation of multiple acceptor-type Cu vacancies is enhanced owing to the repulsion between host Cu+ and Cs+/Rb+ impurities. Consequently, the Cs or Rb impurity is located at the sites of the N accompanied by six neighboring Cu vacancies, forming acceptor defect complexes. This size-dependent isovalent impurity doping scheme opens up an alternative avenue for advancement in optoelectronic devices using monovalent cation-based semiconductors.

Stable aryl-armed dihydrophenazines-based radicals

Stable organic radicals have long been desired for applications in quantum information science and optoelectronic semiconductor. Weakening the reactivity of unpaired electrons is an efficient strategy for fabrication stable radicals. The dual aryl/alkyl-substituted dihydrophenazine (DArPZ/DAlPz) derivatives have attracted a lot of attention due to their potential radical stability characteristics. In this work, three stable DArPZ-based radical cation compounds are obtained through tuning peripheral substituted groups with different electron donating/withdrawing effect to discuss their reactive activity changes in different solvent and aggregate state. Employing systematic experiments from crystallography, spectroscopy and theoretical calculation analyses, some referenceable molecular structure design strategy and the analytical model of evaluating radical behavior are formed and summarized. In addition, radical cations have good masking ability without continuous electrical circulating, implying their application in light-shading electrochromic devices. This work is referable on the design of stable radicals, the establishment of dynamic evaluation strategies and theoretical analysis models for their reactivity.

Pyrene‐based Fluorescent Probe for Rapid and Sensitive Detection of 2,4,6‐Trinitrophenol

AbstractTo rapid and efficient detection of TNP in water (TNP=2,4,6‐trinitrophenol), a pyrenyl‐based double‐charged probe PYPN was employed. The bright orange‐red emission of PYPN was seriously quenched upon the addition of TNP. The detection limit of PYPN for TNP is 0.218 μM. In addition, PYPN shows fast response rate (5 s) to TNP, good stability, excellent selectivity and anti‐interference (pH, anion, cation and other nitro compounds). Furthermore, PYPN can be used to rapidly detect TNP in various types of water samples. The rapid and efficient detection of TNP by PYPN may due to the electron and energy transfer as well as electrostatic interactions.

Composition and growth mechanism of nanoporous anodic fluoride films on stainless steel

Anodizing of 304L stainless steel performed in ethylene glycol solution containing 0.1 M NH4F and 0.1 M H2O at constant voltage under static conditions at 5 °C results in the formation of porous anodic films. Several analysis techniques revealed a rather complex composition of the anodic layer for stainless steel compared to that reported in the literature for iron in the same anodizing conditions. Contrary to what might be expected, the anodic layers consist mainly of iron and chromium fluorides rather than oxides. Furthermore, the multilayer fitting of the Rutherford Backscattered spectroscopy shows a decreasing content of chromium and nickel fluorides from the outermost layer to the innermost layer at the metal/film interface, which is composed only of iron fluoride. Film-assisted dissolution mechanisms and the Gibbs-free energy appear to be responsible for the cation distribution and compounds formed throughout the anodic film. In addition, the thickness and final composition of the anodic layer appear to be dependent on the cleaning process carried out after the anodizing.Graphical abstract

Экологические проблемы развития восстановительных условий в почвах

Excessive moistening of soils leads to the development of restorative conditions in them, an increase in the mobility of Fe, Mn, Cu, a decrease in Eh of less than 400-300 mv, to the transition of NO3 to NH4, NH3, N2, to an increase in the gas phase of soils of CO2, H2S, methane. At the same time, negative consequences appear both in soils and in water and air environments. This has a negative effect on the vegetation cover of hydromorphic soils. The paper shows an increase in denitrification with excessive moistening of soils, a decrease in Eh, NO3 content, mobile phosphates, and a decrease in the ratio of mobile (Ca+Mg):(Fe+Mn), while there is also a change in the content of positively and negatively charged cation compounds in water, soil, and plants. Keywords: SOD-PODZOLIC SOIL, MEADOW-CHERNOZEM SOIL, ANAEROBIOSIS, GLUING, PROCESSES AND REGIMES

Crystal structure and Hirshfeld surface analysis of two organic salts based on 1,3,4-thia-diazole derivatives.

During attempts to achieve inter-action between 2-amino-5-ethyl-1,3,4-thia-diazole with oxalyl chloride and 5-mercapto-3-phenyl-1,3,4-thia-diazol-2-thione with various diacid anhydrides, we obtained two co-crystals (organic salts), namely, 2-amino-5-ethyl-1,3,4-thia-diazol-3-ium hemioxalate, C4H8N3S+·0.5C2O4 2-, (I), and 4-(di-methyl-amino)-pyridin-1-ium 4-phenyl-5-sulfanyl-idene-4,5-di-hydro-1,3,4-thia-diazole-2-thiol-ate, C7H11N2 +·C8H5N2S3 -, (II). Both solids were investigated by single-crystal X-ray diffraction and by Hirshfeld surface analysis. An infinite one-dimensional chain along [100] is generated through O-H⋯O inter-actions between the oxalate anion and two 2-amino-5-ethyl-1,3,4-thia-diazol-3-ium cations in compound (I), and a three-dimensional supra-molecular framework is generated through C-H⋯O and π-π inter-actions. In compound (II), an organic salt is formed by a 4-phenyl-5-sulfanyl-idene-4,5-di-hydro-1,3,4-thia-diazole-2-thiol-ate anion and a 4-(di-methyl-amino)-pyridin-1-ium cation, which are combined by an N-H⋯S hydrogen-bonding inter-action, forming a zero-dimensional structural unit. As a result of inter-molecular π-π inter-actions, the structural units are combined into a one-dimensional chain running along the a-axis direction.

Achieving highly efficient and stable MAPbI3 planar solar cell by embedding Cs+, Fe2+, and Cd2+ metal inorganic cations in perovskite structure

Perovskite solar cells (PSCs) have been attracted the attention of many researchers due to their high conversion efficiency, low manufacturing cost, easy manufacturing steps, high light absorption, and the possibility of changing the photo electronic properties by modifying the chemical structure. Despite the mentioned advantages, the low stability of PSCs and toxicity of lead in the perovskite layer were the challenging issues in this field. In this regard, the use of mixed cation and mixed halide perovskite compounds with high crystal quality, efficiency, and stability has attracted enormous attention. In this project, Fe2+, Cd2+, and Cs+ cations with various contents (Fe2+ + Cd2+: 5% and 10%; Cs+: 5% and 10%) were partially replaced the Pb2+ and CH3NH3+ cations, respectively in the MAPbI3 perovskite structure through a two-step process using spin-coating. The as-synthesized [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 5, 10%, y: 5, 10%) perovskites were characterized with X-ray diffraction (XRD), grazing incidence X-ray diffraction (GIXRD), and field emission scanning electron microscopy (FESEM). The optical properties of prepared compounds were investigated by ultraviolet–visible (UV–Vis) and photoluminescence (PL) spectroscopy. The photovoltaic behavior as well as stability of solar cells containing MAPbI3, [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 5%, y: 5%), and [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 10%, y: 10%) perovskites as active layers were evaluated by current density-voltage (I–V) under AM1.5G illumination.Results showed that partial substitution of CH3NH3+ cations with Cs+ and Pb2+ cations with Fe2+ + Cd2+ in the CH3NH3PbI3 structure improved crystallinity and photovoltaic parameters. The average power conversion efficiency (PCE) of six solar cell containing [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 10%, y: 10%) perovskite layer was 21.04% which was 1.03 and 1.21 times higher than that cells containing [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 5%, y: 5%) and MAPbI3, respectively.The electrochemical impedance spectroscopy (EIS) was utilized to study the charge transfer resistance (Rct) and recombination resistance (Rrec) of prepared solar cells. The Rct and Rrec values of fabricated solar cell were decreased and increased, respectively in the presence of Fe2+, Cd2+, and Cs+ inorganic cations. As a result, the [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a] perovskites can be considered as the appropriate candidate with high efficiency, stability, and low lead content in the planar perovskite solar cells.

Sn(IV) Porphyrin-Based Ionic Self-Assembled Nanostructures and Their Application in Visible Light Photo-Degradation of Malachite Green

A series of porphyrin-based ionic complexes were prepared through the reaction of two porphyrin precursors, 5,10,15,20-tetrakis(4-(2-pyridyl)phenyl)porphyrin H2TPhPyP (1) and trans-dihydroxo [5,10,15,20-tetrakis(4-(2-pyridyl)phenyl)porphyrinato]tin(IV) Sn(OH)2TPhPyP (2), with various acids (HCl, HNO3, CF3COOH, H2SO4, H2CO3, and H3PO4). The complexes were characterized via elemental analysis, 1H nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry, Fourier transform infrared (FT-IR) spectroscopy, ultraviolet (UV)-visible spectroscopy, fluorescence spectroscopy, and field-emission scanning electron microscopy (FE-SEM). Each compound exhibited different results for UV-visible, fluorescence, FT-IR, and FE-SEM studies depending on the counter anions. The complexes possessed different self-assembled nanostructures based on electronic interactions between the cations of compounds 1 and 2 with different counter anions. These aggregated species are stabilized by electrostatic forces and the π-π stacking interactions between the two porphyrin rings, in which the counter anions play an important bridging role. The counter anions also play an important role in controlling the morphology and photocatalytic properties of the as-developed materials. The complexes were then used for the photocatalytic degradation of the malachite green (MG) dye in aqueous media under visible light irradiation for up to 70 min. A morphology-dependent photocatalytic degradation of the MG dye was observed for all the ionic complexes, with efficiencies ranging from 50% to 95%.

Synthesis of Water-Soluble Planar Cobalt(II), Nickel(II), and Copper(II) Hydroxo Clusters Using a (1,4,7-Triazacyclononane)cobalt(III) Complex as a Hydrolysis-Terminating Group.

We report on a group of planar cobalt(II), nickel(II), and copper(II) hydroxo clusters that have a definite composition and are water-soluble: [{Co(tacn)(OH)2}6Co7(OH)12](NO3)2(CF3SO3)6·10H2O (1), [{Co(tacn)(OH)2}6Ni7(OH)12](NO3)2(CF3SO3)6·10H2O (2a), [{Co(tacn)(OH)2}6Ni7(OH)12](BNPP)8·6CH3NO2·8H2O [2b; BNPP = bis(p-nitrophenyl)phosphate], [{Co(tacn)(OH)2}12Ni16(OH)26(OH2)2](SO4)4(CF3SO3)10·30H2O (3a), [{Co(tacn)(OH)2}12Ni16(OH)26(OH2)2](SO4)8(CF3SO3)2·44H2O (3b), [{Co(tacn)(OH)2}2Co2(OH)2(OH2)4](SO4)(CF3SO3)2·4H2O (4), [{Co(tacn)(OH)2}2Ni2(OH)2(OH2)4](SO4)(CF3SO3)2·4H2O (5), and [{Co(tacn)(OH)2}4Cu4(OH)6](ClO4)6·5H2O (6), where tacn is 1,4,7-triazacyclononane. The peripheral of each metal hydroxo cluster plane is chemically protected by the coordination of {CoIII(tacn)(OH)2}+ groups to prevent further hydrolysis. These clusters were synthesized by the reaction of an equimolar amount of [Co(tacn)(OH2)3]3+ and cobalt, nickel, or copper salt at pH values in the range of 6.0-12.0. The structure of the cation in compounds 1, 2a or 2b, 4, and 5 is relevant to the surface structure of the cobalt phosphate and nickel borate oxygen-evolution catalysts; in particular, the Co7(OH)12 core in 1. Moreover, the arrangement of M7(OH)12 in 1 and 2a or 2b and Cu4(OH)6 in 6 represents the solid-state structures of the (111) face of the cubic CoO or NiO and the (002) plane of Cu(OH)2, respectively. Extended X-ray absorption fine structure spectra of an aqueous solution of 1, 2a, 4, and 5 exhibit well-resolved peaks at the first and second coordination spheres due to the M-O and M···M distances, respectively; the solution-state bond distances were estimated, and they agreed well with the bond distances in the solid-state structures.

Supramolecular Salts of Fe(II)/Co(II)/Ni(II)/Cu(II)/Zn(II) 1,10‐Phenanthroline Cations and Similar Complex Tartratostannate(IV) Anions: From Structural Features to Antimicrobial Activity and Enzyme Activation

AbstractIn the present study authors establish the influence of complex cation on the structure formation, crystal packing, antimicrobial activity and enzyme activation of the previously described isostructural [M(phen)3]2[Sn2(μ‐Tart)2(H2Tart)2] complexes (M(II)=Fe(1), Co(2), Ni(3), Cu(4), Zn(5)). Despite the similarity of composition and structure, compounds 1–5 showed different level of antimicrobial activity. A certain pattern in their effectiveness – decreasing of minimal concentrations, resembles the Irving‐Williams series (Fe(II) < Co(II) < Ni(II) < Cu(II) > Zn(II)) and, according to the crystal field theory, correlates with the thermodynamic stability of octahedral cations [M(phen)3]2+. Quantum chemical calculations of cations revealed the insights of the “cations‐cell membranes” interactions and allowed authors to conclude that the cations in compounds 4 and 5 are the most lipophilic, have the highest affinity to the lipophilic cell membrane and, as a result, are more bioactive. It was established that compounds 1–5 had a different influence on the activity of studied α‐L‐rhamnosidases Penicillium tardum ІMB F‐100074 and Penicillium restrictum ІMB F‐100139. Correlation of these results with the crystal voids calculations and Hirshfeld surface analysis allow authors to suggest that presence of the bigger number of water molecules, generation of the branched network of hydrogen bonds and formation of active intermediate complex “enzyme – effector – substrate”, leads to the biggest intensification of activation properties for the compounds 2 and 5.

Two novel cadmium coordination polymers bearing viologen-derived ligand: Structure and photochromism properties

Two novel cadmium viologen coordination polymers (CPs) {[Cd(BTC)(H2O)]·(Mebpy)}n (1) and {[Cd1.5(Mebpy)(BDC)1.5Cl]·(DMF)}n (2) (Mebpy+ = N-methyl-4,4′-bipyridinium cation, DMF = N,N-Dimethylformamide) were prepared in the reaction of CdCl2 with different aromatic carboxylic acid ligands such as 1,3,5-benzenetricarboxylic acid (H3BTC) or 1,4-dicarboxybenzene acid (H2BDC) under hydrothermal conditions in the presence of N-carboxymethyl-4,4′-bipyridinium chloride (CEbpy·Cl). Single-crystal structure analysis revealed that the Cd(II) ions are bridged by BTC3- anions to form a 3D structure with the Mebpy+ cations occupying channel pores in compound 1, while the metal ions are bridged by BDC2- and Cl- anions to form a 3D structure with Mebpy+ cations in compound 2. Interestingly, it has been found that the structure of the two compounds depends on aromatic carboxylic acid ligands. Compounds 1 and 2 exhibit photochromic behavior under xenon lamp irradiation, accompanied by visible color changes from original color to blue.

Structure Tuning, Strong Second Harmonic Generation Response, and High Optical Stability of the Polar Semiconductors Na1-xKxAsQ2.

The mixed cation compounds Na1-xKxAsSe2 (x = 0.8, 0.65, 0.5) and Na0.1K0.9AsS2 crystallize in the polar noncentrosymmetric space group Cc. The AAsQ2 (A = alkali metals, Q = S, Se) family features one-dimensional (1D) 1/∞[AQ2-] chains comprising corner-sharing pyramidal AQ3 units in which the packing of these chains is dependent on the alkali metals. The parallel 1/∞[AQ2-] chains interact via short As···Se contacts, which increase in length when the fraction of K atoms is increased. The increase in the As···Se interchain distance increases the band gap from 1.75 eV in γ-NaAsSe2 to 2.01 eV in Na0.35K0.65AsSe2, 2.07 eV in Na0.2K0.8AsSe2, and 2.18 eV in Na0.1K0.9AsS2. The Na1-xKxAsSe2 (x = 0.8, 0.65) compounds melt congruently at approximately 316 °C. Wavelength-dependent second harmonic generation (SHG) measurements on powder samples of Na1-xKxAsSe2 (x = 0.8, 0.65, 0.5) and Na0.1K0.9AsS2 suggest that Na0.2K0.8AsSe2 and Na0.1K0.9AsS2 have the highest SHG response and exhibit significantly higher laser-induced damage thresholds (LIDTs). Theoretical SHG calculations on Na0.5K0.5AsSe2 confirm its SHG response with the highest value of d33 = 22.5 pm/V (χ333(2) = 45.0 pm/V). The effective nonlinearity for a randomly oriented powder is calculated to be deff = 18.9 pm/V (χeff(2) = 37.8 pm/V), which is consistent with the experimentally obtained value of deff = 16.5 pm/V (χeff(2) = 33.0 pm/V). Three-photon absorption is the dominant mechanism for the optical breakdown of the compounds under intense excitation at 1580 nm, with Na0.2K0.8AsSe2 exhibiting the highest stability.

Реакции пентафенилсурьмы и пента-пара-толилсурьмы с каликсареном [4-t-BuC6H2OH(S-2)

Pentaphenylantimony and penta-para-tolylantimony react with calixarene [4-t-BuC6H2OH(S-2)]4 (СArH) by way of arene elimination and formation of the [Ph4Sb]+[СAr]- × TolH (1), [p-Tol4Sb]+[CAr]- × H2O (2) ionic products with a yield up to 96%. The compound has been identified by IR spectroscopy and X-ray diffraction analysis. According to the X-ray diffraction data, compounds 1 and 2 are ionic complexes with solvate molecules of toluene (1) and water (2). The cation has a tetrahedral coordination of the antimony atom with aryl ligands at the polyhedron vertices; the anion is represented by the deprotonated form of p-tert-butylthiacalix[4]arene. The three tert-butyl groups, the phenyl ring and solvated toluene in the structure of compound 1, and two tert-butyl fragments in the structure of compound 2 are disordered over two positions. The tetrahedral coordination of antimony atoms in the cations of compounds 1 and 2 is slightly distorted. The CSbC angles deviate from the theoretical value and vary within 106.0(4)−117.7(4)° (1), 105.75(15)−112.84(15)° (2). The average Sb–C bond lengths are 2.101(3) and 2.106(4) Å in structures 1 and 2, respectively. The [СAr]- anion is in the cone conformation, the upper rim of which is represented by the tert-butyl groups in the para-position, while the lower one is represented by hydroxy groups, one of which is deprotonated. The СAr–O– bond length (1.318(4) (1) and 1.326(4) (2) Å) is less than the average value of the СAr–OH bond lengths (1.338(4) (1) and 1.343(4) (2) Å), which indicates increasing multiplicity of the bond and localization of a negative charge on the oxygen atom. Intramolecular hydrogen bonds with the neiboring O atom are observed. The H∙∙∙O distances are 2.16, 1.69, 1.77 Å in 1 and 1.92, 1.79, 1.76 Å in 2. Dihedral angles between opposite phenoxide rings are 60.64° and 87.07° (1) and 83.85° and 80.42° (2), which indicates somewhat less symmetric anion in structure 1 than in structure 2. The formation of the crystal spatial structure is due to the formation of hydrogen bonds between ions with participation of oxygen and sulfur atoms, as well as СН∙∙∙π–interactions, while the ions form chains in the crystal of compound 1, and layers in the crystal of compound 2. Complete tables of atom coordinates, bond lengths and valence angles are deposited at the Cambridge Crystallographic Data Center (No. 1850118 (1); No. 2013220 (2); deposit@ccdc.cam.ac.uk or http://www.ccdc.cam.ac.uk/data_request/cif).

Synthesis of benzoyl hydrazones having 4-hydroxy-3,5-dimethoxy phenyl ring, their biological activities, and molecular modeling studies on enzyme inhibition activities.

Hydrazone compounds have high capacity in terms of antioxidant activity and enzyme inhibition activities such as anticholinesterase, tyrosinase, and urease. In this study, benzoyl hydrazones compounds (7a-7m) were synthesized starting from 3,5-dimethoxy-4-hydroxybenzaldehyde. Antioxidant activity of the synthesized compounds was evaluated. In the β-carotene-linoleic acid and ABTS cation radical scavenging activities, compounds 7j, 7e, and 7m stood out as the most active compounds, respectively. In the anticholinesterase enzyme inhibition activity results, compound 7f exhibited the best activity against AChE and BChE enzymes in the synthesis series. In addition, molecular docking analysis was performed to understand the inhibition mechanism of the synthesized compounds with target enzymes at the atomic level. In the light of biological activity and in silico studies, it has the potential to guide studies for the development of new drugs for Alzheimer disease in the future.

Transition-Metal-Complex-Directed Synthesis of Hybrid Iodoargentates with Single-Crystal to Single-Crystal Structural Transformation and Photocatalytic Properties.

We synthesized and characterized three types of isostructural iodoargentates, [TM(phen)3]Ag2I4·3DMF (TM = Co (1), Ni (2), Zn (3)), [TM(phen)3]Ag3I5·DMF (TM = Co (4), Ni (5), Zn (6)), and [TM(phen)3]2Ag8I12·7DMF (TM = Co (7), Ni (8), Zn (9)) (phen = 1,10-phenanthroline, DMF = dimethylformamide) using transition-metal (TM) complexes as the structure-directing agents. Compounds 1-3 and compounds 4-6 feature zero-dimensional anionic [Ag4I8]4- and [Ag6I10]4- clusters, respectively. All of the [TM(phen)3]2+ cations in compounds 1-6 are arranged into a two-dimensional (2D) (6,3) net layer. Interestingly, compounds 1-3 are kinetically unstable in the mother solution, and they can be converted to compounds 4-6 via irreversible single-crystal to single-crystal transformation processes, respectively, with distinct changes in the crystal morphology and structure. Compounds 7-9 feature one-dimensional (1D) zigzag chains constructed from [Ag8I12]4- units. The UV-vis diffuse reflectance measurements demonstrate that compounds 1-9 possess the characteristics of semiconductors with band gaps of 2.58-2.71 eV and visible-light-irradiation-induced photocatalytic activities. Especially, compound 3 possesses higher photocatalytic degradation activity toward crystal violet (CV) and rhodamine B (RhB) in comparison to P25 under identical conditions. Moreover, the mechanism study reveals that the TM complex cations make a great contribution to the photocatalytic activity.

Farnesoid X Receptor Activation Stimulates Organic Cations Transport in Human Renal Proximal Tubular Cells.

Farnesoid X receptor (FXR) is a ligand-activated transcription factor highly expressed in the liver and kidneys. Activation of FXR decreases organic cation transporter (OCT) 1-mediated clearance of organic cation compounds in hepatocytes. The present study investigated FXR regulation of renal clearance of organic cations by OCT2 modulation and multidrug and toxin extrusion proteins (MATEs). The role of FXR in OCT2 and MATEs functions was investigated by monitoring the flux of 3H–MPP+, a substrate of OCT2 and MATEs. FXR agonists chenodeoxycholic acid (CDCA) and GW4064 stimulated OCT2-mediated 3H–MPP+ uptake in human renal proximal tubular cells (RPTEC/TERT1 cells) and OCT2-CHO-K1 cells. The stimulatory effect of CDCA (20 µM) was abolished by an FXR antagonist, Z-guggulsterone, indicating an FXR-dependent mechanism. CDCA increased OCT2 transport activity via an increased maximal transport rate of MPP+. Additionally, 24 h CDCA treatment increased MATEs-mediated 3H-MPP+ uptake. Moreover, CDCA treatment increased the expression of OCT2, MATE1, and MATE2-K mRNA compared with that of the control. OCT2 protein expression was also increased following CDCA treatment. FXR activation stimulates renal OCT2- and MATE1/2-K-mediated cation transports in proximal tubules, demonstrating that FXR plays a role in the regulation of OCT2 and MATEs in renal proximal tubular cells.

Composition and chemical properties of the soils of the city of Santiago de Compostela, northwestern Spain

AbstractUrban soils are still insufficiently studied despite the relevance of their functions in the urban environment. The city of Santiago de Compostela (northwestern Spain) offers interesting opportunities for the study of urban soils because of its geological diversity and the variety of land use and vegetation. With the objective of increasing information about urban soils in Spain, we studied samples from 56 urban soils (0–20 cm) in this city, developed over different parent materials (granites, gneiss, schists, and amphibolites) and under several land uses (lawn areas, forested areas, urban allotment gardens, peri‐urban agricultural soils, and a green roof). The main physicochemical properties of the soils were analyzed, including bulk density, texture, pH, organic matter, cation exchange capacity, available P, and compounds of Fe and Al. The soils are coarse textured (dominant texture is sandy loam) and acidic (pH in water from 4.7 to 6.9), with moderate to high organic matter contents (13–137 g organic C kg−1). Cation exchange capacity ranges from 9 to 48 cmolc kg−1, with Ca as the most abundant exchangeable cation in most soils. Overall, the soils do not show several of the common features of other urban soils, such as alkalinity, high bulk density, or large amounts of artifacts, and their composition is very similar to their natural counterparts in the region. The conservation of these soils with a low degree of artificialization is essential because they can provide a wide range of ecosystem services.

Nanoengineering room temperature ferroelectricity into orthorhombic SmMnO3 films

Orthorhombic RMnO3 (R = rare-earth cation) compounds are type-II multiferroics induced by inversion-symmetry-breaking of spin order. They hold promise for magneto-electric devices. However, no spontaneous room-temperature ferroic property has been observed to date in orthorhombic RMnO3. Here, using 3D straining in nanocomposite films of (SmMnO3)0.5((Bi,Sm)2O3)0.5, we demonstrate room temperature ferroelectricity and ferromagnetism with TC,FM ~ 90 K, matching exactly with theoretical predictions for the induced strain levels. Large in-plane compressive and out-of-plane tensile strains (−3.6% and +4.9%, respectively) were induced by the stiff (Bi,Sm)2O3 nanopillars embedded. The room temperature electric polarization is comparable to other spin-driven ferroelectric RMnO3 films. Also, while bulk SmMnO3 is antiferromagnetic, ferromagnetism was induced in the composite films. The Mn-O bond angles and lengths determined from density functional theory explain the origin of the ferroelectricity, i.e. modification of the exchange coupling. Our structural tuning method gives a route to designing multiferroics.

Ecotoxicological profiling of selected cyanobacterial strains using multi-endpoint effect-directed analysis.

The main goal of this study was to perform an ecotoxicological profiling of terrestrial and aquatic cyanobacterial strains found in different soils or in toxic cyanobacterial blooms in Vojvodina region, Serbia, using the effect-directed analysis (EDA) approach. The applied procedure was based on a series of in vitro or small-scale bioassays covering multiple endpoints in combination with advanced chemical analytical protocols. Non-selective and non-target preparation techniques were used for the extraction of a broad range of chemical compounds present in three terrestrial (Anabaena Č2, Anabaena Č5, Nostoc S8) and three aquatic (Nostoc Z1, Phormidium Z2, Oscillatoria K3) strains. Ecotoxicological endpoints addressed included evaluation of the fish cytotoxicity in vitro (acute toxicity), algal growth inhibition (chronic toxicity), and interaction with cellular detoxification mechanisms. All cyanobacterial strains tested in the 1st tier EDA showed significant effects in terms of chronic toxicity and interaction with cellular detoxification. Three major fractions of different polarities were further tested in the 2nd tier, using bioassays which showed the strongest response: induction of CYP1A1 biotransformation enzyme and inhibition of zebrafish organic anion (Oatp1d1) and cation (Oct1) uptake transporters. Oscillatoria K3 strain was selected for a more detailed 3rd tier EDA, and the obtained results revealed that positive sub-fractions possess polar anion and cation compounds that are reactive to both uptake transporters, and compounds responsible for the strongest effects have a pronounced lipophilic character. Apart from lipophilic non-polar compounds that represent typical phase I substrates, sub-fractions that contained polar substances are also shown to significantly induce CYP1A1.

Counterintuitive deshielding on the 13 C NMR chemical shift for the trifluoromethyl anion.

The trifluoromethyl anion (CF3 - ) displays 13 C NMR chemical shift (175.0 ppm) surprisingly larger than neutral (CHF3 , 122.2 ppm) and cation (CF3 + , 150.7 ppm) compounds. This unexpected deshielding effect for a carbanion is investigated by density functional theory calculations and decomposition analyses of the 13 C shielding tensor into localized molecular orbital contributions. The present work determines the shielding mechanisms involved in the observed behaviour of the fluorinated anion species, shedding light on the experimental NMR data and demystify the classical correlation between electron density and NMR chemical shift. The presence of fluorine atoms induces the carbon lone pair to create a paramagnetic shielding on the carbon nucleus.