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101.
102.
可以通过简单地控制乙酸浓度的方法,在相似的水热合成条件下合成2种同一家族的金属有机框架材料(MOFs):MIL-88B(Cr)和MIL-101(Cr)。在相对较低的乙酸浓度下,可以得到平均粒径为100 nm的MIL-101(Cr),并拥有很高的BET比表面积(3543 m^2·g^-1)。而在相对较高的乙酸浓度下,则可得到另一种具有“呼吸”特性结构的MOF——MIL-88B(Cr)。利用粉末X射线衍射、扫描电镜、N2吸附-脱附分析、热重分析等对它们的结构、形貌、孔隙率等性质做了详细的分析。 相似文献
103.
Donglin He Chengxi Zhao Dr. Linjiang Chen Dr. Marc A. Little Dr. Samantha Y. Chong Rob Clowes Katherine McKie Mark G. Roper Graeme M. Day Dr. Ming Liu Prof. Andrew I. Cooper 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(41):10589-10594
Ethyl acetate is an important chemical raw material and solvent. It is also a key volatile organic compound in the brewing industry and a marker for lung cancer. Materials that are highly selective toward ethyl acetate are needed for its separation and detection. Here, we report a trianglimine macrocycle ( TAMC ) that selectively adsorbs ethyl acetate by forming a solvate. Crystal structure prediction showed this to be the lowest energy solvate structure available. This solvate leaves a metastable, “templated” cavity after solvent removal. Adsorption and breakthrough experiments confirmed that TAMC has adequate adsorption kinetics to separate ethyl acetate from azeotropic mixtures with ethanol, which is a challenging and energy-intensive industrial separation. 相似文献
104.
Deng Xi Wu Liling Deng Yunmeng Huang Siqi Sun Mengtian Wang Xiaowu Liu Qiong Li Ming Li Zhi 《Journal of Sol-Gel Science and Technology》2021,100(3):477-488
Journal of Sol-Gel Science and Technology - This work presents a facile synthesis approach of methyltriethoxysilane (MTES) based aerogels using pure water as the only solvent, and the effects of... 相似文献
105.
Dong Cao Huogao Huang Ming Hu Lin Cui Fanglan Geng Ziyu Rao Hongyun Niu Yaqi Cai Yuehui Kang 《Analytica chimica acta》2015
Natural organic matter (NOM) is a complex and non-uniform mixture of organic compounds which plays an important role in environmental processes. Due to the complexity, it is challenging to obtain fully detailed structural information about NOM. Although Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) has been demonstrated to be a powerful tool for providing molecular information about NOM, multiple ionization methods are needed for comprehensive characterization of NOM at the molecular level considering the ionizing selectivity of different ionization methods. This paper reports the first use of matrix assisted laser desorption/ionization (MALDI) method coupled with FT-ICR-MS for molecular characterization of NOM within a mass range of 200–800 Da. The mass spectral data obtained by MALDI were systematically compared with data generated by electrospray ionization (ESI). It showed that complementary molecular information about NOM which could not be detected by ESI, were provided by MALDI. More unsaturated and aromatic constituents of NOM with lower O/C ratio (O/C ratio < 0.5) were preferentially ionized in MALDI negative mode, whereas more polar constituents of NOM with higher O/C ratio were preferentially ionized in ESI negative mode. Molecular anions of NOM appearing at even m/z in MALDI negative ion mode were detected. The results show that NOM molecules with aromatic structures, moderate O/C ratio (0.7 > O/C ratio > 0.25) and lower H/C ratio were liable to form molecular anions at even m/z, whereas those with higher H/C ratio are more likely to form deprotonated ions at odd m/z. It is speculated that almost half of the NOM molecules identified by MALDI may be aromatic or condensed aromatic compounds with special groups which are liable to absorb electron from other molecules to generate free radical anions during MALDI ionization. 相似文献
106.
HPLC Determination of Lansoprazole and Method Application for the Formulation Development of Enteric‐coated Lansoprazole Pellets 下载免费PDF全文
The aim of this study was to develop a validated HPLC method for the determination of lansoprazole in dissolution medium and pellets. For the formulation development, we investigated the role of 2‐hydroxypropyl‐β‐cyclodextrin (HPβCD) on the dissolution of enteric‐coated pellets of lansoprazole prepared by the solution layering technique using a fluid bed coater. Dissolution results demonstrated the coating using Acryl‐Eze protected the formulations from releasing lansoprazole in acid medium for the first 2 h, and the addition of HPβCD improved the dissolution performance by 189%, compared with the group without HPβCD. The DSC analysis displaced an absence of the endothermic peak for the lyophilized products lansoprazole and HPβCD, and FTIR analysis demonstrated the band broadening, shifting or disappearance compared to the spectra of the physical mixture, which indicated the formation of the inclusion complex between lansoprazole and HPβCD. This study has developed a validated HPLC method to measure lansoprazole in test media and pellets, which was applied successfully to the formula tion development of enteric‐coated pellets. 相似文献
107.
Substituent effects on the potential energy surface of XGeSb (X=H, Li, Na, BeH, MgH, BH2, AlH2, CH3, SiH3, NH2, PH2, OH, SH, F, and Cl) were investigated by using B3LYP/Def2‐TZVP, B3PW91/Def2‐ TZVPP CCSD (T)//B3LYP/Def2‐TZVP methods. The isomers include structures with formal double (Ge=SbX) and triple (Xge=Sb) bonds to germanium‐stibium, so a direct comparison of these types of species is possible. Our model calculations indicate that electropositively substituted Ge=SbX species are thermodynamically and kinetically more stable than their isomeric Xge=Sb molecules. Moreover, the theoretical findings suggest that only the organic substitutions (such as CH3) can make triply bonded Xge=Sb molecule more stable than the doubly bonded Ge=SbX species. 相似文献
108.
Ren Ren Chao‐Jun Chen Xian‐Xian Liu Hui‐Ming Ge Ren‐Xiang Tan Rui‐Hua Jiao 《Helvetica chimica acta》2015,98(10):1435-1441
Three new simple trichothecenes, 15‐acetyltrichoverrol B ( 3 ), 13′‐acetyltrichoverrin B ( 5 ), and 6′‐dehydroxytrichoverrin B ( 6 ), along with five known trichothecenes trichodermadienediol B ( 1 ), trichoverrol B ( 2 ), trichoverrin B ( 4 ), and roridins A ( 7 ) and D ( 8 ), have been isolated from the liquid culture of Myrothecium roridum (strain no. QB‐1). The structures of the new compounds were established by comprehensive analysis of 1D‐ and 2D‐NMR data. All the compounds were evaluated for antifungal activity, only compounds 7 and 8 showed significant antifungal activity against the tested fungi (MIC ranged from 10 to 5 μg/ml). 相似文献
109.
Structure and Absolute Configuration of Aspergilumamide A,a Novel Lumazine Peptide from the Mangrove‐Derived Fungus Aspergillus sp. 下载免费PDF全文
Cai‐Juan Zheng Lu‐Yong Wu Xiao‐Bao Li Xin‐Ming Song Zhi‐Gang Niu Xiao‐Ping Song Guang‐Ying Chen Chang‐Yun Wang 《Helvetica chimica acta》2015,98(3):368-373
A novel lumazine peptide, aspergilumamide A ( 1 ), as well as a known analog penilumamide ( 2 ), were isolated from the mycelia of a marine‐derived fungus Aspergillus sp. (33241), obtained from the mangrove Bruguiera sexangula var. rhynchopetala collected from the South China Sea. The structure of 1 was identified by comprehensive spectroscopic analysis, including 1D‐ and 2D‐NMR, ESI‐MS, and MS/MS experiments. The absolute configuration of 1 was determined by Marfey's method. 相似文献
110.
Wen‐Hao Chen Chang‐Ri Han Yang Hui Da‐Shuai Zhang Xin‐Ming Song Guang‐Ying Chen Xiao‐Ping Song 《Helvetica chimica acta》2015,98(5):724-730
Two new eremophilane‐type sesquiterpenoids, 1α‐hydroxyeremophila‐6,9,11‐trien‐8‐one ( 1 ), 4α‐hydroxyeremophila‐1,9‐diene‐3,8‐dione ( 2 ), and a new friedelane‐type triterpenoid, friedelane‐3α,16β‐diol ( 4 ), along with six known terpenoids, 3 and 5 – 9 , have been isolated from the stems of Drypetes congestiflora. Their structures and relative configurations were elucidated on the basis of detailed spectroscopic analyses and by comparison of their NMR data with those reported in the literature. All of the compounds, 1 – 9 , were isolated for the first time from this species. Compound 3 exhibited moderate cytotoxic activities against the A549 and B16F10 cell lines. 相似文献