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1.
iScience ; 27(4): 109528, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38595797

RESUMO

Diabetic neuropathy (DN) is a major complication of diabetes mellitus. Chondroitin sulfate (CS) is one of the most important extracellular matrix components and is known to interact with various diffusible factors; however, its role in DN pathology has not been examined. Therefore, we generated CSGalNAc-T1 knockout (T1KO) mice, in which CS levels were reduced. We demonstrated that diabetic T1KO mice were much more resistant to DN than diabetic wild-type (WT) mice. We also found that interactions between pericytes and vascular endothelial cells were more stable in T1KO mice. Among the RNA-seq results, we focused on the transforming growth factor ß signaling pathway and found that the phosphorylation of Smad2/3 was less upregulated in T1KO mice than in WT mice under hyperglycemic conditions. Taken together, a reduction in CS level attenuates DN progression, indicating that CS is an important factor in DN pathogenesis.

3.
Phys Chem Chem Phys ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38654606

RESUMO

In our preceding paper (Y. Fukui et al., Phys. Chem. Chem. Phys., 2023, 25, 25594-25602), we reported a systematic study of the Ag+-ion conducting behaviour of silver iodide (AgI)-loaded mesoporous aluminas (MPAs) with different pore diameters and AgI-loading ratios. By optimising the control parameters, the Ag+-ion conductivity has reached 7.2 × 10-4 S cm-1 at room temperature, which is more than three orders of magnitude higher than that of bulk AgI. In the present study, the effect of silver bromide (AgBr)-doping in the AgI/MPA composites on Ag+-ion conductivity is systematically investigated for the first time, using variable-temperature powder X-ray diffraction, differential scanning calorimetry, and electrochemical impedance spectroscopy measurements. The AgBr-doped AgI/MPA composites, AgI-AgBr/MPA, formed a homogeneous ß/γ-AgI-structured solid solution (ß/γ-AgIss) for the composites with AgBr ≤ 10 mol%, above which the composites underwent a phase separation into ß/γ-AgIss and face-centred cubic AgBr solid solutions (AgBrss). The onset temperature of the exothermic peaks attributed to the transition from α-AgI-structured solid-solution phase to ß/γ-AgIss or AgBrss decreased with increasing the AgBr-doping ratio. The room-temperature ionic conductivity of the AgI-AgBr/MPA composites exhibited a volcano-type dependence on the AgBr-doping ratio with the highest value (1.6 × 10-3 S cm-1) when the AgBr content was 10 mol%. This value is more than twice as high as that of the highest conducting AgI/MPA found in our previous study.

4.
Nanoscale ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38655766

RESUMO

The properties of solids could be largely affected by their crystal structures. We achieved, for the first time, the phase control of solid-solution RuIn nanoparticles (NPs) from face-centred cubic (fcc) to hexagonal close-packed (hcp) crystal structures by hydrogen heat treatment. The effect of the crystal structure of RuIn alloy NPs on the catalytic performance in the hydrogen evolution reaction (HER) was also investigated. In the hcp RuIn NPs, enhanced HER catalytic performance was observed compared to the fcc RuIn NPs and monometallic Ru NPs. The intrinsic electronic structures of the NPs were investigated by valence-band X-ray photoelectron spectroscopy (VB-XPS). The d-band centre of hcp RuIn NPs obtained from VB-XPS was deeper than that of fcc RuIn NPs and monometallic Ru NPs, which is considered to enable the hcp RuIn NPs to exhibit enhanced HER catalytic performance.

5.
Elife ; 122024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38512724

RESUMO

Radial neuronal migration is a key neurodevelopmental event for proper cortical laminar organization. The multipolar-to-bipolar transition, a critical step in establishing neuronal polarity during radial migration, occurs in the subplate/intermediate zone (SP/IZ), a distinct region of the embryonic cerebral cortex. It has been known that the extracellular matrix (ECM) molecules are enriched in the SP/IZ. However, the molecular constitution and functions of the ECM formed in this region remain poorly understood. Here, we identified neurocan (NCAN) as a major chondroitin sulfate proteoglycan in the mouse SP/IZ. NCAN binds to both radial glial-cell-derived tenascin-C (TNC) and hyaluronan (HA), a large linear polysaccharide, forming a ternary complex of NCAN, TNC, and HA in the SP/IZ. Developing cortical neurons make contact with the ternary complex during migration. The enzymatic or genetic disruption of the ternary complex impairs radial migration by suppressing the multipolar-to-bipolar transition. Furthermore, both TNC and NCAN promoted the morphological maturation of cortical neurons in vitro. The present results provide evidence for the cooperative role of neuron- and radial glial-cell-derived ECM molecules in cortical development.


Assuntos
Matriz Extracelular , Neurônios , Animais , Camundongos , Neurônios/fisiologia , Matriz Extracelular/metabolismo , Córtex Cerebral/metabolismo , Movimento Celular/fisiologia , Proteoglicanas de Sulfatos de Condroitina/metabolismo
6.
Angew Chem Int Ed Engl ; 63(14): e202400162, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38339815

RESUMO

Ladder systems situated in the dimensional crossover region have attracted much attention because their electronic states and physical properties depend strongly on the electronic correlations among the constituent legs. Generally, two-/three-legged transition metal-oxide ladder compounds are studied as representative ladder systems, but two-/three-dimensional (2D/3D) extensions based on such ladder systems with a few numbers of legs are difficult because of the extreme synthesis conditions. Here, for the first time, we report the successful creation of a 3D extended two-legged ladder compound, [Pt(en)(dpye)I]2(NO3)4 ⋅ 2H2O (en=ethylenediamine; dpye=1,2-Di(4-pyridyl)ethane), which is obtained by simple oxidative polymerization of a small Pt macrocyclic complex using elemental I2. The unique 3D extended lattice consists of 1D mixed-valence halogen-bridged metal chains (⋅⋅⋅Pt-I-Pt-I⋅⋅⋅) and helically arranged macrocyclic units as the constituent legs and rungs, as confirmed by single-crystal X-ray diffraction. Diffuse X-ray scattering analyses and optical measurements revealed that the out-of-phase mixed-valence Pt2+/Pt4+ arrangement arises from the weak interchain correlation among adjacent legs. In addition, this compound shows an increase in proton conductivity by a factor of up to 1000, depending on humidity.

7.
Inorg Chem ; 63(9): 4196-4203, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38377386

RESUMO

We report on a new organic conductor κ″-(ET)2Cu[N(CN)2]Br (κ″-Br), which is the first polymorph of an organic superconductor κ-(ET)2Cu[N(CN)2]Br (κ-Br), where ET denotes bis(ethylenedithio)tetrathiafulvalene. κ″-Br has a similar κ-type arrangement of ET molecules to κ-Br, but, in contrast to the orthorhombic κ-Br, which has ordered polyanion chains, presents a monoclinic crystal structure with disordered polymeric anion chains. To elucidate the electronic state of κ″-Br, we performed band calculations as well as transport, magnetic, and optical measurements. The calculated band dispersion, magnitude of electron correlation, and room-temperature optical conductivity spectra of κ″-Br were comparable to those of κ-Br. Despite these similarities, the κ″-Br salt exhibited a semiconducting behavior. The electron spin resonance and Raman spectroscopies indicated that there is neither magnetic nor charge order in κ″-Br, suggesting the occurrence of Anderson localization due to disordered anion layers.

8.
ACS Appl Mater Interfaces ; 16(7): 8984-8992, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38326087

RESUMO

Plasmonic Schottky devices have attracted considerable attention for use in practical applications based on photoelectric conversion, because they enable light to be harvested below the bandgap of semiconductors. In particular, silicon-based (Si) plasmonic Schottky devices have great potential for useful photodetection in the near-infrared region. However, the internal quantum efficiency (IQE) values of previously reported devices are low because the Schottky barrier is excessively high. Here, we are the first to develop AuAg nanoalloy-n-type Si plasmonic Schottky devices by cathodic arc plasma deposition. Interestingly, it is found that a novel nanostructure, which leads to the improvement of responsivities, is formed. Moreover, these plasmonic nanostructures can be fabricated in only ∼1 min. The fabricated AuAg nanoparticle-film structure enables proper control of the Schottky barrier height and increases the area of the Schottky interface for electron transfer. As a result, the considerably enhanced IQE of our device at a telecommunication wavelength of 1310 nm (1550 nm) without external bias is 4.6 (6.5) times higher than those in previous reports, and these responsivities are a record high. This approach can be applied to realize efficient photodetection in the NIR region and extend the use of light below the bandgap of semiconductors. This paves the way for future application advancements in a variety of fields, including photodetection, imaging, photovoltaics, and photochemistry.

9.
Dalton Trans ; 53(7): 3159-3166, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38240125

RESUMO

The interaction between photochromic 8-methoxy-1',3',3'-trimethyl-6-nitro-spiro[chromene-2,2'-indole] (MNSP) and cobalt(II) hexafluoroacetylacetonate yields a deep red-violet solution due to the coordination-induced transition of MNSP from a colorless closed state to a colored open merocyanine (MC) form. The resulting complex {CoII(hfac)2·MNSP} (1) is obtained as crystals, and its structure at 250 K shows the coordination of two oxygen atoms from MNSP with CoII, forming a distorted octahedral surrounding around CoII. The unit cell of 1 contracts below 170 K by 5.5%, which is accompanied by shortening O-Co bonds and altering O-Co-O angles in the structure solved at 150 K. The χMT value of 3.06 emu K mol-1 at 300 K indicates the formation of high-spin CoII (S = 3/2) with a large orbital contribution characteristic of the octahedral surrounding. The contraction of the unit cell of 1 below 170 K provides a reversible 2.2% change of χMT in the 170-160 K range during heating and cooling regimes without hysteresis. The electron paramagnetic resonance signal of 1 was simulated with g-values of gx = 2.342, gy = 2.364, and gz = 2.084, and an isotropic g-factor of 2.267. The temperature-dependent χMT and field-dependent magnetization of 1 allow us to determine a positive zero-field splitting parameter of +20.1 cm-1. A study of the dynamic properties of 1 shows slow magnetic relaxation for CoII in a static field of 1000 Oe. Magnetic hysteresis loops were observed for 1 at 0.5 and 2 K; these loops are closed in the zero field region but opened at fields higher than ±100 and 700 Oe, respectively. The collapse of the loop is observed at 5 K. Excitation of the solution of 1 with green light decreases partially the intensity of the bands of the complex, whereas subsequent exposure of this solution to UV light partially restores these intensities.

10.
Commun Biol ; 7(1): 129, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38272969

RESUMO

Neudesin, originally identified as a neurotrophic factor, has primarily been studied for its neural functions despite its widespread expression. Using 8-week-old neudesin knockout mice, we elucidated the role of neudesin in the spleen. The absence of neudesin caused mild splenomegaly, shortened lifespan of circulating erythrocytes, and abnormal recovery from phenylhydrazine-induced acute anemia. Blood cross-transfusion and splenectomy experiments revealed that the shortened lifespan of erythrocytes was attributable to splenic impairment. Further analysis revealed increased erythrophagocytosis and decreased iron stores in the splenic red pulp, which was linked to the upregulation of Fcγ receptors and iron-recycling genes in neudesin-deficient macrophages. In vitro analysis confirmed that neudesin suppressed erythrophagocytosis and expression of Fcγ receptors through ERK1/2 activation in heme-stimulated macrophages. Finally, we observed that 24-week-old neudesin knockout mice exhibited severe symptoms of anemia. Collectively, our results suggest that neudesin regulates the function of red pulp macrophages and contributes to erythrocyte and iron homeostasis.


Assuntos
Anemia , Ferro , Animais , Camundongos , Ferro/metabolismo , Macrófagos/metabolismo , Camundongos Knockout , Fagocitose/fisiologia , Receptores de IgG/metabolismo , Baço/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo
11.
Development ; 151(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38117077

RESUMO

During endochondral ossification, chondrocytes secrete a proteoglycan (PG)-rich extracellular matrix that can inhibit the process of cartilage maturation, including expression of Ihh and Col10a1. Because bone morphogenetic proteins (BMPs) can promote cartilage maturation, we hypothesized that cartilage PGs normally inhibit BMP signalling. Accordingly, BMP signalling was evaluated in chondrocytes of wild-type and PG mutant (fam20b-/-) zebrafish and inhibited with temporal control using the drug DMH1 or an inducible dominant-negative BMP receptor transgene (dnBMPR). Compared with wild type, phospho-Smad1/5/9, but not phospho-p38, was increased in fam20b-/- chondrocytes, but only after they secreted PGs. Phospho-Smad1/5/9 was decreased in DMH1-treated or dnBMPR-activated wild-type chondrocytes, and DMH1 also decreased phospho-p38 levels. ihha and col10a1a were decreased in DMH1-treated or dnBMPR-activated chondrocytes, and less perichondral bone formed. Finally, early ihha and col10a1a expression and early perichondral bone formation of fam20b mutants were rescued with DMH1 treatment or dnBMPR activation. Therefore, PG inhibition of canonical BMP-dependent cartilage maturation delays endochondral ossification, and these results offer hope for the development of growth factor therapies for skeletal defects of PG diseases.


Assuntos
Osteogênese , Proteoglicanas , Animais , Osteogênese/genética , Proteoglicanas/genética , Proteoglicanas/metabolismo , Peixe-Zebra/genética , Cartilagem/metabolismo , Condrócitos/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo
12.
J Am Chem Soc ; 146(1): 181-186, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38153046

RESUMO

High-entropy oxide nanoparticles (HEO NPs) have been intensively studied because of their attractive properties, such as high stability and enhanced catalytic activity. In this work, for the first time, denary HEO NPs were successfully synthesized using a continuous supercritical hydrothermal flow process without calcination. Interestingly, this process allows the formation of HEO NPs on the order of seconds at a relatively lower temperature. The synthesized HEO NPs contained 10 metal elements, La, Ca, Sr, Ba, Fe, Mn, Co, Ru, Pd, and Ir, and had a perovskite-type structure. Atomic-resolution high-angle annular dark-field scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy measurements revealed homogeneous dispersion of the 10 metal elements. The obtained HEO NPs also exhibited a higher catalytic activity for the CO oxidation reaction than that of the LaFeO3 NPs.

13.
Int J Colorectal Dis ; 39(1): 12, 2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38157027

RESUMO

PURPOSE: Transversus abdominis plane (TAP) block is a safe, effective, and promising analgesic procedure, but TAP block only cannot overcome postoperative pain. We conducted a prospective randomized study to evaluate postoperative pain control using multimodal analgesia (MA) combined with a single injection TAP block compared with epidural analgesia (EA) after laparoscopic colon cancer surgery. METHODS: Sixty-seven patients scheduled for elective laparoscopic colon cancer surgery were enrolled in this study and randomized into EA and MA groups. The primary endpoint was the frequency of additional analgesic use until postoperative day (POD) 2. The VAS score, blood pressure, time to bowel movement, time to mobilization, postoperative complications, and length of hospital stay were also compared between the two groups. RESULTS: Sixty-four patients (EA group, n = 33; MA group, n = 31) were analyzed. The patient characteristics did not differ markedly between the two groups. The frequency of additional analgesic use was significantly lower in the MA group than in the EA group (P < 0.001), whereas the VAS score did not differ markedly between the two groups. The postoperative blood pressure on the day of surgery was significantly lower in the MA group than in the EA group (P = 0.016), whereas urinary retention was significantly higher in the EA group than in the MA group (P < 0.001). CONCLUSION: MA combined with a single injection TAP block after laparoscopic colon cancer surgery may be comparable to EA in terms of analgesia and superior to EA in terms of urinary retention.


Assuntos
Analgesia Epidural , Neoplasias do Colo , Laparoscopia , Retenção Urinária , Humanos , Músculos Abdominais , Analgésicos , Analgésicos Opioides , Neoplasias do Colo/cirurgia , Neoplasias do Colo/complicações , Laparoscopia/efeitos adversos , Laparoscopia/métodos , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/etiologia , Estudos Prospectivos
14.
Anticancer Res ; 43(11): 4887-4895, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37909947

RESUMO

BACKGROUND/AIM: P53 is the most frequently mutated tumor suppressor gene among all cancers. In human cancers, specific residues of p53 are mutated at a high frequency, and those mutations are known as hotspot mutations. Mutant p53 promotes tumor progression through the gain-of-function (GOF) mechanism. However, its biological characteristics, especially its metastatic potential, owing to different hotspot mutations in gastric cancer remain unclear. In the present study, we investigated the p53-depended metastatic phenotype. MATERIALS AND METHODS: This study examined the differences in the metastatic potential of wild-type, mutant-p53-R175H, and mutant-p53-R273H NUGC-4 gastric cancer cells in vitro and in vivo. RESULTS: NUGC-4-mutant-p53-R175H cells showed significant cell proliferation, healing and invasive abilities in proliferation, wound healing and invasion assay, respectively, compared to wild-type and mutant-p53-R273H cells. Both NUGC-4-mutant-p53 cell types expressed epithelial-mesenchymal transition (EMT)-related proteins. Furthermore, NUGC-4-mutant-p53-R175H cells showed less attachment to the extracellular matrix and greater expression of EMT-related proteins than NUGC-4-mutant-p53-R273H cells. Regarding the peritoneal dissemination model, NUCG-4-mutant-p53-R175H and NUCG-4-mutant-p53-R273H cells demonstrated less frequent formation of dissemination nodules than NUGC-4-empty cells. In contrast, liver metastases were more frequent and greater in number in NUCG3-mutant-p53-R175H than in the other cell lines. CONCLUSION: Our results suggest that differences in the p53 status, even in the hotspot mutation site, affect not only the characteristics of the cells but also the metastatic ability of gastric cancer.


Assuntos
Neoplasias Gástricas , Humanos , Oncologia , Fenótipo , Neoplasias Gástricas/genética , Proteína Supressora de Tumor p53/genética
15.
J Wound Care ; 32(Sup11): S14-S23, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37907367

RESUMO

OBJECTIVE: Intra-soft tissue and intramedullary antibiotic perfusion (iSAP and iMAP), which combine continuous administration of antibiotic solution to the wound and negative pressure wound therapy (NPWT), have been reported to be a useful management approach for hard-to-heal ulcers in the field of orthopaedic surgery. We report the efficacy of this treatment and discuss the key points. METHOD: The recipients of this treatment had contaminated fresh severe trauma with a high risk of infection, or hard-to-heal ulcers which were expected to be difficult to manage with conventional NPWT alone. Continuous administration of 1200µg/ml of gentamicin (GM) solution to the wound was performed along with NPWT. The GM solution was administered subcutaneously using a small catheter for iSAP, while intramedullary administration used a bone marrow needle for iMAP. RESULTS: iSAP was employed in all 10 patients who took part, and iMAP in three of these patients. The average treatment time was 13.6 days with iSAP and 9.3 days with iMAP. The mean serum GM level during the therapy was 1.02µg/ml. Moderate GM-induced acute kidney injury was suspected in one case, but resolved spontaneously after GM administration was stopped. Favourable wound bed preparation was achieved in all cases without recurrence of infection. CONCLUSION: Combination with continuous suction by NPWT is able to keep the local concentration of antibiotic above the minimum inhibitory concentration of biofilm-coated bacteria within the wound. We have referred to this treatment as continuous local antibiotic perfusion. Further investigation of local pharmacodynamics in the wound and side-effects of this treatment are warranted.


Assuntos
Tratamento de Ferimentos com Pressão Negativa , Humanos , Antibacterianos/uso terapêutico , Úlcera , Cicatrização , Perfusão
16.
Inorg Chem ; 62(43): 17736-17744, 2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37850881

RESUMO

The reaction between an excess of Fe(CO)5 with {Cryptand(K+)}(C60•-) produced the salt {Cryptand(K+)}2{[Fe(CO)2]2-µ2-η2:η2-η2:η2-(C60)2}2-·4C6H4Cl2 (1) containing negatively charged iron-bridged fullerene dimers. In these dimers, the C60 cages are linked via two Fe(CO)2 fragments, forming short Fe-C(C60) bonds with a length of 2.070(3) Å and via two intercage C-C bonds with a length of 1.566(3) Å. Interfullerene center-to-center distance is short, being 9.02 Å. Thus, the coordination-induced dimerization of fullerenes is observed in 1. The dimer is negatively charged, with additional negative electron density mainly localized on iron atoms and, to a lesser extent, on the C60 cages, as revealed by optical and electron paramagnetic resonance spectra. These dimers have a diamagnetic singlet ground state with a small singlet-triplet gap of 25 K; consequently, they transfer to a paramagnetic state with two S = 1/2 spins per dimer above 50 K. Previously, different dimers with isomeric structures were obtained starting from {Cryptand(K+)}(C60•-) and Fe3(CO)12. However, these dimers exhibit diamagnetic properties, owing to the formation of a Fe-Fe bond. In contrast, in dimer 1, the Fe atoms are positioned too far apart to form such a bond, preserving the spin on Fe. We assume that both dimers are formed through the same [Fe(CO)3](C60•-) intermediate, but the subsequent interaction of this intermediate with Fe3(CO)12 or its dimerization yields different dimers. Therefore, the starting carbonyls can control the structures and properties of the resulting dimers.

17.
J Am Chem Soc ; 145(44): 24005-24011, 2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-37883673

RESUMO

Technetium (Tc), atomic number 43, is an element that humans cannot freely use even in the 21st century because Tc is radioactive and has no stable isotope. In this report, we present molybdenum-ruthenium-carbon solid-solution alloy (MoxRu1-xCy) nanoparticles (NPs) that are expected to have an electronic structure similar to that of technetium carbide (TcCy). MoxRu1-xCy NPs were synthesized by annealing under a helium/hydrogen atmosphere following thermal decomposition of metal precursors. The obtained NPs had a solid-solution structure in the whole composition range. MoxRu1-xCy with a cubic structure (down to 30 atom % Mo in the metal ratio) showed a superconducting state, and the transition temperature (Tc) increased with increasing Mo composition. The continuous change in Tc across that of TcCy indicates the continuous control of the electronic structure by solid-solution alloying, leading to pseudo-TcCy. Density functional theory calculations indicated that the synthesized Mo0.53Ru0.47C0.41 has a similar electronic structure to TcC0.41.

18.
Phys Chem Chem Phys ; 25(37): 25594-25602, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37721053

RESUMO

A systematic study of Ag+-ion conducting behavior in Ag+-loaded porous materials was conducted over the entire sub-10 nm region for the first time. The effects of the pore diameter of mesoporous aluminas (MPAs) and the amount of silver iodide (AgI) loaded into MPAs were investigated using N2 gas adsorption/desorption, powder X-ray diffraction, differential scanning calorimetry, and electrochemical impedance spectroscopy measurements. Confinement of AgI in the mesoporous space lowers the phase transition temperature between the ß/γ- and α-phases relative to that of bulk AgI. The AgI-loading into the MPAs with smaller pores led to a more significant decrease in the transition temperature, possibly because the smaller AgI nanoparticles in the pores must have a higher surface energy to stabilize the high-temperature phase. The room-temperature ionic conductivity exhibits a volcano-type dependence on the pore diameter with the highest value when AgI was loaded into MPA with a pore diameter of 7.1 nm (7.2 × 10-4 S cm-1 at room temperature). Concerning the 7.1 nm-MPA, the room-temperature ionic conductivity was the highest for the nearly fully occupied composite, which is more than three orders of magnitude higher than that of the bulk AgI. The present study reveals that the Ag+-ion conductivity in AgI/MPA composites can be controlled by optimizing the pore diameter of MPA and the AgI-loading ratio.

19.
Dalton Trans ; 52(34): 12049-12056, 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37581295

RESUMO

Heterobimetallic {[Co(CO)4]-[InIII(Pc2-)]} (1) and (Cp*2Cr+){[Mn(CO)5]-[InIII(Pc˙3-)]}·2C6H4Cl2 (2) complexes based on indium(III) phthalocyanine (Pc) were obtained as crystals. The complexes were synthesized by single (1) and double (2) reduction of indium(III) phthalocyanine chloride in the presence of transition metal carbonyls. Complex 1 contains dianionic Pc2- macrocycles. Thus, the coordinated Co(CO)4 carbonyl accepts an electron in the one-electron reduction forming a diamagnetic [Co(CO)4]- anion. Complex 2 contains a heterobimetallic {[Mn(CO)5]-[InIII(Pc˙3-)]}- anion and paramagnetic Cp*2Cr+ counter cations. Therefore, in the double reduction, electrons are transferred to Mn(CO)5 forming a diamagnetic [Mn(CO)5]- anion and to the Pc2- macrocycle forming a paramagnetic radical Pc˙3- trianion. Such assignments for 1 and 2 are in line with optical spectra, crystal structures and the data of magnetic measurements. The spectrum of 1 in the UV-visible range is similar to that of the starting InIIIClPc. The formation of 2 is accompanied by an essential blue-shift of the Q-band of Pc as well as by the appearance of an intense NIR band at 1005 nm characteristic of Pc˙3-. Compound 1 is EPR silent and diamagnetic, whereas the value of the effective magnetic moment of 2 is 4.24µB at 300 K, which corresponds to the contribution of S = 1/2 (Pc˙3-) and S = 3/2 (Cp*2Cr+) spins. Both weakly coupled paramagnetic centers (J = -0.41 cm-1) are observed in the EPR spectra.

20.
Dalton Trans ; 52(32): 11222-11233, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37525575

RESUMO

A series of trianion assemblies of hexaazatriphenylenehexacarbonitrile {HAT(CN)6} and hexaazatrinaphthylenehexacarbonitrile {HATNA(CN)6} with three Fe(II) or Co(II) ions: {cryptand(K+)}3·{HATNA(CN)6·(FeIII2)3}3-·2C6H4Cl2 (1), {cryptand(K+)}3·{HATNA(CN)6·(CoIII2)3}3-·2C6H4Cl2 (2), and (CV+)3·{HAT(CN)6·(CoIICl2)3}3-·0.5(CVCl)·2.5C6H4Cl2 (3) are synthesized (CVCl = crystal violet). Salt 1 has a χMT value of 9.80 emu K mol-1 at 300 K, indicating a contribution of three high-spin FeII (S = 2) and one S = 1/2 of HATNA(CN)6˙3-. The χMT value increases with cooling up to 12.92 emu K mol-1 at 28 K, providing a positive Weiss temperature of +20 K. Such behavior is described using a strong antiferromagnetic coupling between S = 2 and S = 1/2 with J1 = -82.1 cm-1 and a weaker FeII-FeII antiferromagnetic coupling with J2 = -7.0 cm-1. As a result, the spins of three Fe(II) ions (S = 2) align parallel to each other forming a high-spin S = 11/2 system. Density functional theory (DFT) calculations support a high-spin state of CoII (S = 3/2) for 2 and 3. However, the χMT value of 2 and 3 is 2.25 emu K mol-1 at 300 K, which is smaller than 6 emu K mol-1 calculated for the system with three independent S = 3/2 and one S = 1/2 spins. In contrast to 1, the χMT values decrease with cooling to 0.13-0.36 emu K mol-1 at 1.9 K, indicating that spins of cobalt atoms align antiparallel to each other. Data fitting using PHI software for the model consisting of three high-spin Co(II) ions and an S = 1/2 radical ligand shows very large CoII-L˙3- coupling for 2 and 3 with J1 values of -442 and -349 cm-1. The CoII-CoII coupling via the ligand (J2) is also large, being -100 and -84 cm-1, respectively, which is more than 10 times larger than that of 1. One of the reasons for the J2 increase may be the shortening of the Co-N(L) bonds in 3 and 2 to 2.02(2) and 1.993(12) Å. DFT calculations support the population of the quartet state for the Co3 system, whereas the high-spin decet (S = 9/2) state is positioned higher by 680 cm-1 and is not populated at 300 K. This is explained by the large CoII-CoII coupling. Thus, a balance between J1 and J2 couplings provides parallel or antiparallel alignment of the FeII and CoII spins, leading to high- or low-spin ground states of {L·[MII(Hal)2]3}3-.

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