Chemical constituents of belamcanda chinensis (l.) dc - Lê Minh HàThe NMR spectra of 4 were very similar to those of 3 except for the additional signals of the methoxyl group suggesting that 4 was a derivative of 3. Three methoxyl groups at δ 3.88/136.2, 3.89/152,7, and 3.94/131,2, four methine carbons at δ 7,90 /153,3, 6.48/93.9, 6.68/105,7, and δ 6.68/109,4 were identified from 13C-NMR, DEPT 90, DEPT 135...
5 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 524 | Lượt tải: 0
Palladium complex immobilized on sba-15 as an efficient catalyst for the heck reaction of aryl iodides with styreneIn summary, highly ordered mesoporous silica SBA-15 was synthesized and functionalized via silane chemistry with N-[3- (trimethoxysilyl)propyl]ethylenediamine to create surface amino groups. The aminofunctionalized SBA-15 was allowed to react with 2-acetyl pyridine to form an immobilized bidentate iminopyridine ligand, which was complexed wi...
10 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 593 | Lượt tải: 0
Effect of alumina particle size on properties of electrolessly deposited composite Ni-P/Al2O3Hardness of composite layers with different sizes of co-depsosited alumina particles was measured and sumarized on Tab. 2. Results show that hardness increases with increasing alumina particle size. Since the composition of the matrix Ni-P does not change much as alumina particle size changes (Tab. 1), this result can be explained by the two...
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Synthesis of some derivatives of n-(2,3,4,6-tetra-oacetyl-β-d-glucopyranosyl)-n’-(benzothiazole-2’-yl) thioureasIn the 13C-NMR spectra, it could be noticed that the number of carbon atoms in spectra and this one in molecular formulas of each thioureas were identical each other. For example, the compound of thiourea IIIc is represented in Fig. 3, there were some resonance peaks in high-field606 region of 30.609 - 14.605 ppm that’s indicated the present...
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Suzuki reactions of aryl halides with phenylboronic acid using imidazolium-Based ionic liquid as a green solvent under microwave irradiation - Phan Thanh Son NamIn summary, an imidazolium-based ionic liquid, 1-hexyl-3-methylimidazolium bromide, was synthesized from n-hexyl bromide and Nmethylimidazole under microwave irradiation condition in a yield of 84% within 1 minute. The ionic liquid was characterized by 1H, 13C NMR and MS spectra, which were in good agreement with the literature. The ionic liq...
7 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 496 | Lượt tải: 0
Influence of magnetic field on properties of electrodeposited feco layer - Mai Thanh TungInfluence of magnetic field with two configurations (i) parallel to electrode and (ii) perpendicular to electrode were investigated. Results showed that the magnetic field with both configurations did not influence on the surface technology and crystal structure of the deposited film. Meanwhile, the magnetic field and magnetic to surface con...
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Influence of silica resource from rice husk on structure of hzsm-5 zeolite - Le Thi Hoai NamHZSM-5 material was successfully synthesized from rice husk silica. The characterization results show that the synthesized material has the crystallinity equivalent to that of the standard sample. Besides the conventional pores system exiting in zeolite structure, there is another pores system having diameters in the range of 10 - 50 nm (mes...
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Anthraquinones from hedyotis pinifolia - Le Hoang DuyThe ethyl acetate extract was subjected to a series of chromatographic procedures, leading to the isolation of 12 mg of fine orange needles. Initial inspection of the 1H and 13C-NMR spectra of this product indicated the doubling signals for most protons and carbons. These facts suggested that perhaps the product was a dimeric anthraquinone o...
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Fabrication of silver-Nanoparticles-embedded polymer masterbatchs with excellent antibacterial performanceThe silver-nanoparticles-embedded PEbased polymer masterbatchs with excellent antibacterial performance were successfully synthesized. A fine dispersion of silver nanoparticles in PE polymer matrix was obtained with use of appropriate dispersion supporting reagents of Disperplast 1010 (BYK), Chimassorb 81 (Ciba), Irganox 1010 (Ciba). At a si...
8 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 459 | Lượt tải: 0
Heck reactions of aryl halides with styrene using 1-Butyl-3-methylimidazolium bromide ionic liquid as a green solvent under microwave irradiationIn summary, three ionic liquids including 1- butyl-3-methylimidazolium bromide, 1-hexyl-3- methylimidazolium bromide, and 1-octyl-3- methylimidazolium bromide, respectively, were synthesized under microwave irradiation condition, and characterized by 1H and 13C NMR, and MS. The three ionic liquids were used as green solvents the Heck cross-c...
8 trang | Chia sẻ: honghp95 | Ngày: 01/12/2020 | Lượt xem: 519 | Lượt tải: 0
