CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2022
·
IF 4.119
Jinbo Ouyang,Xiaohong Xing,Limin Zhou,Chuntao Zhang,Jerry.Y.Y. Heng
Vanillin (VAN) is widely used in medicine, food and optoelectronics, but its low solubility leads to the decrease of bioavailability and increase of application costs. Three APIs-nicotinamide (NIC), isonicotinamide (INM) and isoniazid (INH) were chosen to form cocrystals with VAN, aiming at improving the solubility of VAN and APIs simultaneously. Two cocrystals (VAN-NIC, VAN-INM) were obtained through cocrystallization while VAN reacted with INH to form one novel compound (VAN-INH). The crystal structures were characterized by single-crystal X-ray diffraction (SCXRD), Powder X-ray diffraction (PXRD), Fourier-Transform Infrared Spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC). The melting temperatures of VAN-NIC and VAN-INM cocrystals are between this of VAN and APIs. Compared with pure VAN and APIs, the solubility and dissolution rate of VAN-NIC and VAN-INM are significantly increased. The melting temperature of VAN-INH is greater than that of VAN and INH, and the solubility and dissolution rate is not increased significantly. The intermolecular energy between VAN and APIs as well as lattice energies of cocrystals/novel compound were computed to elucidate the formation mechanism and stability. The present investigation opens a new pathway for the development of natural product-drug cocrystals to improve solubility and dissolution rate of natural product .
研究领域:
药学
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材料化学
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计算化学
✓ 已验证
DOI
高影响因子
OPTICS AND LASER TECHNOLOGY
·
2022
·
IF 4.939
Yifeng Shi,Gerile Naren,Ying Zhang,Jiakang Han,Aorigele Bohnuud
Amino acid rare-earth complexes are widely used due to their unique physical and chemical properties. In this study, three kinds of neodymium (III) complexes with octanoyl-aminocarboxylate ligands (abbr. Nd(oct-ala) 3 , Nd(oct-phe) 3 , Nd(oct-ser) 3 ) were prepared by a chemical reaction method in methanol as the solvent. The chemical formulas and coordination modes of the neodymium complexes were determined by elemental analysis, 1 H NMR and FT-IR. Additional analyses by X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that the neodymium complexes have lamellar irregular shapes and long-range disordered amorphous structures. The thermal performance of the complexes was determined by differential scanning calorimetry (DSC) and thermal gravimetry-differential thermal analysis (TG-DTA). Nd(oct-phe) 3 and Nd(oct-ser) 3 appeared glassy when heated. The solubility of the complexes in various organic reagents was also measured. The optical properties of the complexes were examined using UV–Vis absorption, polarizing microscopy observations, fluorescence spectra, quantum yield, and fluorescence lifetime. The luminescence properties of the complexes as a function of temperature were further observed by analysis of temperature-dependent emission spectra. The polarizing microscopy observations show that the three neodymium complexes exhibited the characteristic properties of thermotropic liquid crystals. UV–Vis, fluorescence spectroscopy, and quantum yield results show that they have excellent light absorption and luminescence properties. Temperature-dependent emission spectra show that the complexes have good luminescence properties in the temperature range of 25–160 °C. The powdered complexes and the complexed solutions in methanol were irradiated with 380 nm UV light, resulting in blue-violet light emission. A warm white-light device was constructed to further verify the luminescence of the complexes after combining with three kinds of rare-earth complexes (Nd(oct-phe) 3 , Eu(oct-phe) 3 , and Tb(oct-phe) 3 . The color rendering index (CRI) and color temperature (CCT) were measured. In addition, the density functional theory (DFT) was used to determine the geometric structures ( Fig S1 ), and obtain 1 H NMR, FT-IR spectra of the neodymium complexes ( Fig S2, S3 ). Their structures were further examined by comparing the calculated with the experimental spectra. The results show that the ligands coordinate to the central Nd 3+ through the bidentate chelation mode.
研究领域:
化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Yan-nan Wang,Jin Li,Zhenyu Yuan,Fanli Meng
An optical fiber triethylamine (TEA) gas sensor based on a hollow malposition structure (HMS) platform with CQDs@BiOBr gas-sensing layer is proposed. The CQDs@BiOBr gas-sensing material is coated onto the surface of the hollow core fiber (HCF) using a dip-coating method. The misaligned structure is designed to guide light transmission within the cladding of the HCF and excite the evanescent field. The heterojunction formed between CQDs and BiOBr enhances the separation efficiency of electron-hole pairs, improving the transfer speed of charge carriers during the gas adsorption process. Experimental results show that the sensitivity of sensor at room temperature is 3.53 pm/ppm, which is 2.43 times higher compared to a sensor coated with BiOBr alone. Additionally, the response and recovery times of sensor are 12 s and 36 s, respectively, with a limit of detection (LOD) of 5.67 ppm. DFT calculations provide insight into the electronic transfer pathways and electron cloud distribution during the gas adsorption process, further validating the crucial role of the CQDs@BiOBr heterojunction in enhancing gas-sensing performance. The proposed optical fiber TEA gas sensor shows significant potential for applications in environmental monitoring and industrial safety.
研究领域:
光学工程
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材料科学
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化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 73
·68695-68704
·
IF 3.289
Yiming Ren,Ruizhu Yang,Lang Shao,Hao Tang,Shaofei Wang,Jianlong Zhao,Jingrong Zhong,Chuipeng Kong
Phosphoramide-modified ordered mesoporous silica (SBA-DEPA) materials were prepared via a two-step process involving: (1) the synthesis of phosphoramide via amidation of phosphoryl chloride with a primary amine and (2) modification of the phosphoramide onto SBA-15. The successful preparation was confirmed by FT-IR and NMR spectroscopy. As indicated by the ICP-AES and XRF analysis results, the phosphoramide group has a grafting ratio as high as 12.5%. The morphological information and N2 adsorption–desorption technique proved the highly ordered structure and large specific area of the material, respectively. An excellent performance for uranium sorption was found with a loading maximum of 311.6 mg g−1, a marked promotion relative to unmodified SBA-15. A strong pH and CO2 dependence suggested that near neutral conditions favored the maximum uranium sorption. To our surprise, the sorption took only 5 min to reach a 90% capacity and 20 min for equilibrium, which is extraordinary when compared to many other sorbent materials. The ionic strength partially influences the sorption, which indicates outer and inner sphere sorption both play parts in the process. A sorption capacity of over 90% of the original indicates the excellent reproducibility of SBA-DEPA. DFT calculations based on cluster models suggested a ‘tri-dentate-like’ structure for the uranyl-surface binding site, which may explain the excellent sorption ability of this material.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 2
·596-605
·
IF 2.936
Juan Yi,Zong-Yan Zhao,Yu-An Wang
Compound solid solutions have attracted intensive attention due to their adjustable structure, electronic structure, and optical properties. Despite tremendous advances in compound solid solution preparations, combining a rare metal compound and a bismuth compound with the same crystal phase by forming a compound solid solution is still challenging but fascinating. For example, RE1−xBixVO4 with a zircon-type structure exhibits tunable band gaps and photoluminescence performance with varying RE compositions. Herein, Yb1−xBixVO4 solid solutions with continuous monophasic phase prepared by a facile synthesis strategy that is combined with co-precipitation and hydrothermal methods are reported. By doping a small amount of Tm3+, YbxBi1−xVO4 solid solutions can achieve a broad range up-conversion photoluminescence from UV-light to NIR-light. Combined with DFT calculations, the underlying mechanism of experimental observations is explained. In these up-conversion processes, the existence of Tm3+ is an essential factor. In particular, the NIR-to-UV up-conversion photoluminescence of YbxBi0.98−xVO4: 2 mol% Tm3+ solid solution is very interesting and a worthy phenomenon for further studies. As such, designing compound solid solutions may provide a new avenue for controllable up-conversion efficiencies in semiconductor nanocrystals and also a novel insight into the rational tunable up-conversion process for applications in biological labeling and imaging.
研究领域:
材料科学
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光学
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY
·
2023
·
IF 9
Wei Yu,Chao Liu,Luxi Tan,Qibin Li,Liyong Xin,Shukun Wang
The thermal stability and decomposition mechanism of octamethyltrisiloxane (MDM) were studied using a combination of experimental, ReaxFF simulation, and DFT calculation techniques. After heating MDM for 24 h at 250 °C and 1 MPa, the signature product CH 4 was detected, along with liquid products such as hexamethyldisiloxane (MM) and decamethyltetrasiloxane (MD 2 M). The decomposition rate of MDM remained relatively constant in the temperature range of 250 °C–320 °C but exhibited a sharp increase at 350 °C. Higher pressure was found to promote MDM polymerization. The oxygen (O) atoms displayed a large negative electrostatic potential , while the hydrogen (H) and silicon (Si) atoms exhibited a large positive potential. The electrostatic interaction facilitated the rearrangement reactions, with O and carbon (C) atoms being the most reactive for electrophilic and free radical reactions. The thermal decomposition of MDM initiated with the cleavage of Si–C bonds. Hydrogen extraction reactions between methyl radicals and MDM, as well as Si–O bond rearrangement reactions of demethylated radicals with MDM, further promoted MDM decomposition and the formation of CH 4 and siloxane oligomers . These findings are significant for the safe application of MDM as a working fluid in ORC system.
研究领域:
化学工程
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材料科学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Xiuqin Dong,Jianhang Tian,Junwei Lei,Yifei Chen
Copper as a non-noble metal catalyst has great prospects in the hydrogenation of acetic acid to ethanol. In this paper, Cu-MnO/SBA-15 catalysts with highly catalytic performance and stability were prepared. The mechanism was elucidated by experiments and DFT calculations . The Cu and MnO were coexistent on reduced x Cu y Mn/SBA-15. Appropriate Cu/Mn ratio was beneficial for increasing the Cu surface area and reducing the size of Cu. The rate-controlled step was found and the MnO could effectively lower the difficulty of acetaldehyde formation by dioxyethylidene. DFT calculations indicated that the formation of ethyl acetate at the Cu-MnO interface was largely prevented. The optimal catalytic hydrogenation activity was obtained for 9Cu1Mn/SBA-15, with the conversion of acetic acid and selectivity of ethanol of 99.9% and 90.1%, respectively. The catalytic activity could remain within 72 h which was more stable than the original Cu-based catalyst.
研究领域:
催化化学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2025
·
IF 4.7
Lei Wang,Chaofan Sun
Exploring the impact of photoisomerization on the antioxidant activity of compounds is of great significance in fields such as medicine and daily chemical industry. Herein, the influence of photoisomerization on the antioxidant properties of resveratrol (RES) upon photoexcitation in different solvents was systematically investigated via 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging experiments and quantum chemistry computational methods. The frontier molecular orbitals and global descriptive parameters calculated using density functional theory (DFT) and time-dependent DFT (TD-DFT) methods indicate that trans-RES exhibits higher reactivity in the S 0 state, while cis-RES shows enhanced reactivity in polar solvents under the S 1 state. Natural population analysis (NPA) charges and spin density distribution further confirm that cis-RES and trans-RES exhibit more reactive sites in the S 1 state. In addition, both theoretical and experimental results demonstrate that photoexcitation and increased solvent polarity significantly enhance the antioxidant capacity of RES. These findings highlight the modulation of antioxidant capacity by molecular configuration and environmental factors, providing fresh insights for the design and optimization of antioxidant compounds.
研究领域:
药理学
·
量子化学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
INORGANICA CHIMICA ACTA
·
2021
·
IF 2.545
Dan Zheng,Ting-Hong Huang,Cheng Luo,Jing Tang
Three dinuclear Cu(I) complexes, [Cu 2 (pnd)(PPh 3 ) 4 ](BF 4 ) 2 (1) , [Cu 2 (pnd)(dppp) 2 ] (BF 4 ) 2 (2) , and [Cu 2 (pnd)(DPEphos) 2 ](BF 4 ) 2 (3) (PPh 3 = triphenylphosphine , dppp = 1, 3-bis (diphenylphosphino)propane, DPEphos = bis(2-diphenylphosphinophenyl)ether, pnd = N , N ’-bis (pyridin-2-ylmethylene)naphthyl-1, 5-diimine), have been prepared and characterized by IR, 1 H NMR, 31 P NMR, 13 C NMR, XRD , elemental analysis and X-ray crystal structure analysis. The structural analysis reveals that the flexible pnd in 1 – 3 acts in a trans bridging coordination mode to connect two Cu + ions, forming a S-shape conformation, while each of Cu (I) ion is four-coordinate N2P2, adopting a distorted-tetrahedral geometry. DFT calculations show that the HOMOs of complexes 1 – 3 are primarily located on the copper d -orbital and the phosphine ligand, together with a specific contribution of pnd, while LUMOs are mostly composed of pnd with admixed Cu(I) d-orbital character. Corresponding calculations of atomic charges indicate that the charge of the copper atom in complexes 1 – 3 is below + 1, while the total charges of the coordinated atoms are 0.743–0.786. Moreover, the solid-state emission spectra of complexes 1 – 3 show the existence of broad emission bands at 350–550 nm.
研究领域:
无机化学
·
理论化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Chen Wang,Guo Lin,Jiling Zhao,Shixing Wang,Libo Zhang,Yunhao Xi,Xiteng Li,Ying Ying
A novel adsorbent (UiO-66-TA) was presented by modifying metal-organic framework composites with thioctic acid. UiO-66-TA were characterized by fourier transform infrared (FT-IR), field emission scanning electron microscopy (FESEM), thermogravimetric (TG), Brunner-Emment-Teller (BET) measurement and X-ray photoelectron spectroscopy (XPS), which indicating that it had excellent morphology and specific surface area. The adsorption performances of UiO-66-TA for Au(III) were studied. The results showed that UiO-66-TA had a strong adsorption capacity under acidic conditions and the optimal pH was 2.0. Isotherm and kinetic adsorption were also conducted and found that the experimental values correspond to Langmuir model and pseudo-second-order isotherm model, indicating that the mechanism is mainly chemical adsorption on a uniform surface. Wastewater experiment showed that UiO-66-TA can be used for highly selective recovery Au(III) in actual life. The regeneration and thermodynamic experiments indicated that UiO-66-TA can be reused and were a spontaneous endothermic process. XPS analysis and the zeta potential proved that the main adsorption mechanisms were ion exchange and chelation. DFT calculation found that there are two ways to combine Au with S on UiO-66-TA and their distances are 2.38 Å and 2.39 Å, indicating that the gold and sulfur play a major role in chelation. In summary, UiO-66-TA was a hopeful adsorbent and could be used to collect gold ions from wastewater in a sustainability perspective.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Fuxing Xu,Shutong Yang,Fangling Wu,Chuan-Fan Ding
The functions and applications of dipeptides have been reported to possess unique characteristics compared to that of proteins or amino acids. Naturally occurring amino acids, except for glycine, are chiral molecules; thus, for each type of dipeptide there are four possible isomers. Isomeric structural analysis of dipeptides is important for measuring the quality of dipeptide products, as well as understanding their chemical and biological functions in humans. In the present study, a rapid and simple method for isomeric recognition of protonated dipeptides H-D/ l -Phe-D/L-X-OH, where X = hydrophobic amino acids, including alanine (Ala), isoleucine (Ile), leucine (Leu), proline (Pro), tryptophan (Trp), valine (Val), phenylalanine (Phe), and methionine (Met), was developed and investigated. Mixed solutions of dipeptides and cyclodextrins (CDs) were prepared for the production of gas phase, non-covalent complex ions by electrospray ionization (ESI). Trapped ion-mobility mass spectrometry (TIMS-MS) was subsequently used to investigate the corresponding ion mobilities (IM). The TIMS and density functional theory (DFT) results showed that the chiral structure of different dipeptides can be distinguished by β-CD, which indicates that different isomeric complexes have different collision cross sections (CCSs) and spatial conformations. The relative content of isomeric dipeptides mixtures was also obtained in the ratio range from 10:1 to 1:10 to measure the detection limits. Our work provides a direct analytical method for determining isomeric dipeptides, which could potentially have wide applications in the field of chiral recognition.
研究领域:
生物化学
·
分析化学
·
药物化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Hang Liu,Shengqiang Song,Pin-Wen Guan,Guixuan Wu,Mithun Nath
Despite great potential in several applications, the pseudo-ternary system Al 2 O 3 –CaO–Cr 2 O x is an overlooked phase diagram due to the formation of a few toxic, carcinogenic, and water-soluble Cr 6+ compounds. In the research paper, equilibrium experimentation of selected compositions was conducted at 1073, 1373, and 1673 K and investigated using XRD , SEM-EDS, and leaching tests. Further, thermodynamic modeling of limited databases of the pseudo-ternary system Al 2 O 3 –CaO–Cr 2 O x was validated using DFT calculations. Including the recently discovered novel phase CaAl 2 Cr 2 O 7 (wuboraite), the seven phases not available in the SGTE SUBstance (SSUB) database, along with the CaCrO 4 and CaCr 2 O 4 phases existing therein, were modeled using Density Functional Theory (DFT). Based on the above experiments and the present CALPHAD model, we have calculated the isothermal sections (1073, 1373, and 1673 K) of the Al 2 O 3 –CaO–Cr 2 O x system for different oxygen partial pressures ( P (O 2 )= 0.21 atm and P (O 2 )= 10 −8 atm).
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）