JOURNAL OF CHEMICAL THERMODYNAMICS
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2014
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IF 2.423
Pan Liang,Qiu-Yue Kang,Lu Du,Zhi-Hong Liu
Two pure microporous materials, Rb[ZnBP 2 O 8 ] and Cs[ZnBP 2 O 8 ], have been synthesized and characterized by XRD, FT-IR, DTA-TG techniques and chemical analysis. The molar enthalpies of solution of Rb[ZnBP 2 O 8 ] and Cs[ZnBP 2 O 8 ] (s) in 3 mol · dm −3 HCl (aq), of Zn(PO 3 ) 2 (s) in (HCl + H 3 BO 3 ) (aq), and of RbCl (s)/CsCl (s) in [Zn(PO 3 ) 2 + HCl + H 3 BO 3 ] (aq) were measured by microcalorimeter at T = 298.15 K, respectively. With the incorporation of the previously determined enthalpy of solution of H 3 BO 3 (s) in 3 mol · dm −3 HCl (aq), together with the use of the standard molar enthalpies of formation for Zn(PO 3 ) 2 (s), RbCl (s)/CsCl (s), H 3 BO 3 (s), HCl (aq) and H 2 O (l), the standard molar enthalpies of formation of −(3198.5 ± 1.2) kJ · mol −1 for Rb[ZnBP 2 O 8 ] and −(3212.7 ± 1.2) kJ · mol −1 for Cs[ZnBP 2 O 8 ] at T = 298.15 K were obtained on the basis of the appropriate thermochemical cycle. In addition, the molar enthalpy of formation of −(2944.4 ± 1.2) kJ · mol −1 for [ZnBP 2 O 8 ] − has also been estimated by a group contribution method, which can be used to predict the Δ f H m θ of the other similar borophosphates. Moreover, these data have been further used to compare the thermodynamic stability of this series of borophosphates.
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FLUID PHASE EQUILIBRIA
·
2013
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IF 2.379
Zheng Cao,Yonghong Hu,Yumei Kai,Jiaojiao Li,Wenbiao Zhi,Wenge Yang
In our study the solubilities of crotonic acid in methanol, ethanol, 2-propanol, 1-butanol, acetic acid, N,N -dimethylformamide, ethyl acetate and acetonitrile were experimentally determined over the temperature range of (278.15–333.15) K at around 5 K intervals by employing an analytical stirred-flask method. The experimental solubility data were well correlated with the modified Apelblat equation, in different kinds of solvents the values of the sum of MPD were 6.3. The thermodynamic functions were evaluated by two methods and the results were the same. The dissolving process was endothermic, entropy-driving and non-spontaneous. It was necessary to use the experiment data and correlation models in the reaction and purification of crotonic acid.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2015
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IF 2.999
Yaying Shen,Chang Liu,Peipei Hou,Mingjia Zhi,Chunmei Zhou,Wenxiang Chai,Qichun Zhang,Yi Liu
Three new quaternary thioantimonates(III) ACu 2 SbS 3 (A = K, Rb, Cs) have been prepared through the surfactant-thermal method. X-ray single crystal diffraction analysis reveals that these three compounds are isostructural and feature a two-dimensional layered structure. Both experimental and theoretical studies confirm they are semiconductors with narrow band gaps. Our results clearly indicated that surfactants, as reaction media, could offer exciting opportunities for exploring novel multinary chalcogenides with diverse crystal structures and interesting physical properties.
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Natural Products and Bioprospecting
·
2016
·Vol. 6
·期 6
·297-303
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IF 0
Geng Chang-An,Chen Ji-Jun
Swerilactones H–K ( 1 – 4 ) as four unprecedented secoiridoid trimers represent a new type of natural product, which has attracted much interest of natural chemists due to their novel skeletons and promising bioactivity. In order to well understand their MS fragmentation behaviors, they were investigated by electrospray ionization ion-trap time-of-flight multistage product ion mass spectrometry (ESI-IT-TOF-MS n ) for the first time. The protonated molecules ([M+H] + ) of swerilactones J and K, and deprotonated molecules ([M−H] − ) of swerilactones H, J and K were readily observed in the conventional single-stage mass spectra (MS); however only the [M+Cl] − ion for swerilactone I was obtained in negative mode. Based on the MS n study, the fragmentation pathways of swerilactones H and I in negative mode, and swerilactones J and K in both positive and negative modes were proposed. The neutral losses of H 2 O, CO, CO 2 and C 2 H 4 O moieties are the particular elimination from the precursor ions due to the presence of hydroxyl, δ -lactone and 1- O -ethyl moieties in their structures, of which the retro-Diels–Alder cleavage was the most particular dissociation. The fragment ions at m/z 341 and 291 in negative mode can be considered as the diagnostic ions for secoiridoid trimers. This investigation will provide valuable information for their fast characterization from complicated natural mixtures and extensive understanding their structural architectures.
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PubMed
JOURNAL OF ETHNOPHARMACOLOGY
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2024
·
IF 4.8
Danilo de Souza Costa,Rayssa A. Cajas,Carla Monteiro Leal,Lara S. Aleixo de Carvalho,Lara Cruz de Souza,Lucas Fukui-Silva,Josué de Moraes,Ademar A. Da Silva Filho
Ethnopharmacological relevance Acmella oleracea (L.) R. K. Jansen, commonly referred to as “Jambu”, is a valuable medicinal plant native to the Amazon regions. Inflorescences of A. oleracea is utilized as local anesthetic properties and for its insecticidal, antiparasitic, and anthelmintic attributes. Aims of this study This study aimed to evaluate the in vitro and in vivo antiparasitic properties of A. oleracea extract and spilanthol (SPL) against Schistosoma mansoni . Materials and methods The ethanolic extract of A. oleracea inflorescences (AoE) was prepared, analyzed by HPLC-DAD, and characterized by UHPLC-HRMS/MS. SPL was isolated from AoE by chromatographic fractionation. The antischistosomal properties of AoE and SPL were evaluated in vitro against adult schistosomes and in preclinical assays using murine models of patent S. mansoni infection. Results Through UHPLC-HRMS/MS analysis, 14 alkamides were annotated in AoE. HPLC-DAD analysis of AoE revealed a peak with a substantial relative area of ∼85%, which was isolated and identified as SPL. AoE and SPL caused mortality of adult schistosomes ex vivo , showing EC 50 values of 32.6 μg/mL and 27.8 μM, respectively, without affected Vero cells or Caenorhabditis elegans . In preclinical studies, the oral administration (400 mg/kg) of AoE and SPL resulted in significant reductions in worm burden of 28% and ∼42%, respectively. Additionally, SPL exhibits remarkable effects on oogram, decreasing egg burden and the number of immature eggs by over 80%, while also promoting significant reductions in hepato- and splenomegaly. Conclusions The research underscores the antischistosomal activity of A. oleracea highlighting the potential of SPL as a lead for the development of new schistosomicidal drugs and encouraging further studies to validate the traditional anthelmintic use of A. oleracea inflorescences.
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ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Rui Zhu,Peng Sun,Guofeng Cui,Jie Zhao,Yaoguang Yu
Ion transportation via the mixed mechanisms of hydrogels underpins ultrafast biological signal transmission in nature, and its application to the rapid and sensitive sensing detection of human specific ions is of great interest for the field of medical science. However, current research efforts are still unable to achieve transmission results that are comparable to those of bioelectric signals. Herein, 3D interconnected nanochannels based on poly(pyrrole-co-dopamine)/poly(vinyl alcohol) (P(Py-co-DA)/PVA) supernetwork conductive hydrogels are designed and fabricated as stimuli-responsive structures for K+ ions. Distinct from conventional configurations, which exhibit rapid electron transfer and permeability to biosubstrates, interconnected nanofluidic nanochannels collaborated with the P(Py-co-DA) conductive polymer in the supernetwork conductive hydrogel significantly improve conductivity (88.3 mS/cm), ion transport time (0.1 s), and ion sensitivity (74.6 mV/dec). The faster ion response time is attributed to the synergism of excellent conductivity originating from the P(Py-co-DA) polymer and the electronic effect in the interconnected nanofluidic channels. Furthermore, the supernetwork conductive hydrogel demonstrates K+ ion selectivity relative to other cations in biofluids such as Na+, Mg2+, and Ca2+. The DFT calculation indicates that the small solvation energy and low chemical transfer resistance are the main reasons for the excellent K+ ion selectivity. Finite element analysis (FEA) simulations further support these experimental results. Consequently, the P(Py-co-DA)/PVA supernetwork conductive hydrogels enriched with the 3D interconnected nanofluidic channels developed in this work possess excellent sensing of K+ ions. This strategy provides great insight into efficient ion sensing in traditional biomedical sensing that has not been explored by previous researchers.
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高影响因子
KINETICS AND CATALYSIS
·
2024
·Vol. 65
·期 3
·251-260
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IF 1.3
Yang Zhi,Luo Mingsheng,Liu Qinglong,Li Chenmeng,Wang Yatao,Li Hongjuan,Yao Lifei
Abstract The direct production of higher alcohols from syngas in a single step remains a great challenge. In this work, a series of K and Ni promoted Mo 2 C/Al 2 O 3 catalysts were prepared by impregnation method to enhance the selectivity of Mo 2 C-based catalysts for the one-step conversion of syngas to higher alcohols. The catalysts were continuously tested under the following conditions: 300°C, 3.0 MPa, velocity—11.50 \({\text{Lg}}_{{{\text{Mo}}}}^{{ - 1}}\) h –1 , H 2 /CO ratio of 2. The catalysts promoted with K and Ni demonstrated the highest total alcohol selectivity of 67.7%. Moreover, the selectivity for total C 2+ alcohols reached as high as 56%, with 37% being ethanol. X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H 2 -TPR) and X-ray photoelectron spectroscopy (XPS) characterization data reveal that K can promote the crystallinity of β-Mo 2 C, lower the catalyst reduction temperature and increase the proportion of high-valent Mo on the catalyst surface. In addition, adding Ni as a promoter to the KMo 2 C/Al 2 O 3 catalyst can generate a synergistic effect to further enhance the catalytic activity and the selectivity of higher alcohols.
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JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
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2024
·
IF 2.5
Zelai Cheng,Xi Wang,Xingyu Huo,Yulan Jing,Hua Su
Ni 0.42-x/3 Nb x /3 Cu 0.18 Zn 0.4 Mn x Fe 1.98− x O 4− δ ( x = 0–0.1) materials, possessing a high saturation magnetization, high dielectric constant, and narrow ferromagnetic resonance linewidth, were prepared via the solid-phase reaction method. The cation distribution, as well as the dielectric and gyromagnetic properties, were studied in detail. Mn 2+ and Nb 5+ incorporated in the lattice occupy tetrahedral site, causing the redistribution of cation and the reduction of A–B superexchange interaction. This leads to an increase in saturation magnetization followed by a decrease. The introduction of appropriate amounts of Mn 2+ and Nb 5+ ions reduces the magnetocrystalline anisotropy constant | K 1 | and thus reduces the ferromagnetic resonance linewidth ( ΔH ). Furthermore, high polarisability of Mn 2+ and Nb 5+ causes the increase in the dielectric constant of the ferrites. At x = 0.08, excellent gyromagnetic and dielectric properties, including a high dielectric constant ( ε ’ = 15.4@100 MHz), high saturation magnetization (4π M s = 4577 G), and narrow ferromagnetic resonance linewidth (Δ H = 129 [email protected] GHz) for the NiCuZn ferrite, was achieved. Finally, a K-band microstrip circulator operating at 20.8 to 28 GHz was designed. The simulation showed that the isolation of the circulator in the working frequency band is greater than 20 dB, showing the potential of the prepared ferrites in microwave circulators.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2024
·
IF 2
Shouxiang Jiang,Kai Fu,Xiangyu Sun,Xin Huang,Wenjun Xie,Chengfei Wang,Haoran Li,Xia Jiang,Yongjin Zou,Gengxiu Zheng,Guan Wang
The solubilities of glutathione in four binary solvent mixtures (water + acetone, water + 1,4-dioxane, water + acetonitrile, and water + tetrahydrofuran) were measured using a dynamic laser monitoring method at temperatures ranging from 278.15 to 318.15 K. The molar fraction solubility of glutathione in the binary solvent increased with increasing water content and temperature. The modified Apelblat, CNIBS/R-K, Van’t Hoff–Jouyban–Acree, Apelblat–Jouyban–Acree, and NRTL were applied to calculate the solubility of glutathione in these mixtures. The relative average deviation and root-mean-square deviation indicated a good correlation between the experimental and model solubility data. In addition, the KAT-LSER model was used to evaluate the solvent effect in the solvent–solvent and solvent–solute interactions. The results showed that the nonspecific dipolarity/polarizability interactions between the solvent and the solute were the main influencing factors, followed by the hydrogen bonding interactions between the solvent and the solute.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2024
·
IF 2
Yueheng Wang,Ziyu Zhuang,Yanfei Fan,Dandan Gao,Dongdong Li
Ammonium ion is of the same charge as alkali ions and with similar ionic radius as potassium, rubidium, and cesium ions. Solid solutions are very common between ammonium and alkali salts, which is of great interest for understanding the geology, soil, and environment fate of these elements. In this study, the solid–aqueous equilibrium in the NH4Cl + RbCl + H2O and NH4Cl + CsCl + H2O systems was determined at 298.15 K. For each system, two incontinuous solid solutions, i.e. (NH4,Rb)Cl(α) and (Rb,NH4)Cl(β), or (Cs,NH4)Cl(α) and (NH4,Cs)Cl(β), presented, and their composition and structure were studied using Schreinemakers’ wet residues analysis, XRD, and Raman characterization. The equilibrium between these solid solutions and aqueous solutions were well modeled using an integrated solution equilibrium calculator program, in which a Pitzer-Simonson-Clegg model and a subregular model were implemented for describing the nonideality of aqueous phase and solid solution. According to the experimental and thermodynamic modeling results, NH4Cl can dissolve RbCl and CsCl in the solid state (NH4,Rb)Cl(α) or (NH4,Cs)Cl(β) with limited solid solubilities of 0.18 or 0.051 in mole fraction, respectively. RbCl or CsCl can also dissolve NH4Cl in the solid state (Rb,NH4)Cl(β) or (Cs,NH4)Cl(α) with limited solid solubilities of 0.37 and 0.095 in mole fraction, respectively.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2024
·
IF 2
Shouxiang Jiang,Guangbing Zheng,Xiangyu Sun,Junwei Wang,Haibo Mu,Wenjun Xie,Chengfei Wang,Haoran Li,Xia Jiang,Gengxiu Zheng,Guan Wang
The solubility of paliperidone in 15 pure solvents (methanol, ethanol, i-propanol, n-propanol, n-butanol, n-pentanol, n-hexanol, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, acetone, acetonitrile, tetrahydrofuran, and 1,4-dioxane) was determined using a dynamic laser monitoring method at 0.1 MPa and temperatures ranging from 288.15 to 328.15 K. With increasing temperature, the molar fraction solubility of paliperidone in each solvent also increased. Acetonitrile exhibited the lowest solubility at 288.15 K, whereas 1,4-dioxane showed the highest at 328.15 K. Various models, including the modified Apelblat, Yaws, λh, Wilson, and NRTL models, were applied to correlate and analyze the experimental data. The relative average deviation and root-mean-square deviation indicated strong correlation between experimental and modeled solubility data. Additionally, based on the Wilson model, the thermodynamic analysis of paliperidone dissolution suggested an entropy-driven and spontaneous process, with entropy exerting a greater influence on Gibbs free energy than enthalpy.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2024
·
IF 2
Cheng Yang,Haijun Yan,Qianhe Huang,Wenge Yang,Yonghong Hu
Esculetin is derived from the leaves of lemons of Rutaceae and the bark of bittersweet ash, belladonna, mandala, and Rehmannia plants. In this research, the solubility of esculetin in ten solvents such as ethyl acetate, isobutyl alcohol, water, methanol, acetonitrile, n-propyl alcohol, isopropyl alcohol, n-butanol, ethanol, and acetone was determined by utilizing static equilibrium-high performance liquid chromatography (HPLC) under standard atmospheric pressure conditions and temperatures in the range of 273.15 to 318.15 K. Among the above ten pure solvents, water displayed the least solubility, while methanol exhibited the highest solubility. At the same temperature (T = 273.15 ∼ 318.15 K), the solubility of esculetin increased with the increase of the molar ratio of soluble solvents. Similarly, when the temperature increases (T = 273.15 ∼ 318.15 K), the solubility of the three binary solvents increases under the condition of a constant molar ratio. The above results suggest that the main factor affecting the solubility of esculetin in the solvent may be the polarization/bipolarity of the solvent. The experimental data was fitted by five thermodynamic models (the Buchowski–Ksiazaczak λh model, the Modified Apelblat model, the Jouyban–Acree model, the SUN model, and the CNIBS/R-K model), and the relative average deviation and root-mean-square deviation of the data were calculated, which proved that the correlation of the solubility data and the five models was relatively good. XRD and DSC were used to detect the crystal form and stability of esculetin during the experiment.
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