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991.
Lin Yang Guoli He Ruifeng Yin Dr. Lili Zhu Prof. Dr. Xiaoxia Wang Prof. Dr. Ran Hong 《Angewandte Chemie (International ed. in English)》2014,53(43):11600-11604
Polyketide antibiotics bearing skipped polyols represent a synthetic challenge. A SiCl4‐promoted oxonia‐Cope rearrangement of syn,syn‐2‐vinyl‐1,3‐diols was developed to forge an array of 1,5‐pentenediols, thus providing versatile motifs for the preparation of 1,2,3,5‐stereoarrays in a highly stereoselective manner. Further exploration with Sn(OTf)2 realized the rearrangement of a cross‐aldehyde which tactically warrants the utility of the current approach to access complex polyketides. The origin of high stereoselectivity is attributed to a chairlike anti‐conformation of the oxonium ion intermediate. 相似文献
992.
Chong Zhao Dan Lei Prof. Li‐Hua Gan Dr. Zhu‐Xia Zhang Prof. Chun‐Ru Wang 《Chemphyschem》2014,15(13):2780-2784
Sc2S@C84 has recently been detected but not structurally characterized. 1 Density functional theory calculations on C84 and Sc2S@C84 show that the favored isomer of Sc2S@C84 shares the same parent cage as Sc2C2@C84, whereas Sc2S@C84:51383, which violates the isolated‐pentagon rule, is the second lowest energy isomer with the widest HOMO–LUMO gap and shows high kinetic stability. The analysis shows that Sc2S@C84:51575 is favored when the temperature exceeds 2 800 K and it can transform into the most favorable isomer Sc2S@C84:51591. Molecular orbital analysis indicates that both Sc2S and Sc2C2 formally transfer four electrons to the cage, and quantum theory of atoms in molecules analysis demonstrates that there is a covalent interaction between Sc2S and C84:51591. The IR spectra of Sc2S@C84 are provided to aid future structural identification. 相似文献
993.
矿石及冶金渣试样与过氧化钠在700℃熔融,用温水浸取,以一定量盐酸酸化后定容。分取部分试样溶液使其中铍(Ⅱ)与铍试剂Ⅲ在EDTA、氯化铵和氨水底液中,生成稳定的配合物,该配合物于-0.80V(vs.SCE)处产生一灵敏的吸附波,其峰电流的二阶导数与铍(Ⅱ)的质量浓度在0.004~0.20mg·L-1范围内呈线性关系,检出限(3S/N)为0.3μg·L-1。方法用于了7个矿石及冶金渣样品的分析,所得测定值与认定值一致。方法的加标回收率在96.0%~105%之间,相对标准偏差(n=6)在1.3%~9.7%之间。 相似文献
994.
Porous CuO micro‐/nanostructures with clean surface, prepared through Cu2(OH)2CO3 precursor followed by calcination in air, were proven to be an effective peroxidase mimic. They can quickly catalyze oxidation of the peroxidase substrate 3,3′,5,5′‐tetramethylbenzidine (TMB) in the presence of H2O2, producing a blue color. The obtained porous CuO micro‐/nanostructure have potential application in wastewater treatment. The apparent steady‐state kinetic parameter was studied with TMB as the substrate. In addition, the potential application of the porous CuO in wastewater treatment was demonstrated with phenol‐containing water as an example. Such investigation not only confirms the intrinsic peroxidase‐like activity of micro‐/nanostructured CuO, but also suggests its potential application in wastewater treatment. 相似文献
995.
Zhi-Xiang Han Bo-Song Zhu Tong-Liang Wua Qing-Qing Yang Yong-Lai Xue Zhen Zhang Xiang-Yang Wua 《中国化学快报》2014,25(1):73-76
In this paper, 2-carboxybenzaldehyde rhodamine B thiohydrazine(1) was synthesized and developed as a fluorescent probe to recognize Hg2+in DMF/H2 O(1:9, v/v) solution with high selectivity. The probe can be applied to the quanti?cation of Hg2+with a linear concentration range covering from 1.0×10-7mol/L to 1.0×10-5mol/L(R2= 0.9985) and a detection limit of 4.2×10-8mol/L. The experiment results show that the response of probe 1 to Hg2+is pH-independent in a wide range from 4.0 to 9.0. Moreover, the probe 1 exhibits excellent selectivity toward Hg2+over other common metal cations. Most importantly, the probe can be employed to monitor Hg2+in living cells using fluorescent imaging technique with satisfied results. 相似文献
996.
In this paper, an efficient synthesis of 5-alkynyl-1,2,3-triazoles through a one-pot aerobic oxidative coupling reaction of various alkynes and azides has been developed. Further derivatization of 5-alkynyl-1,2,3-triazoles readily yielded 5-carbonyl-1,2,3-triazoles, 5-carboxylic-1,2,3-triazole, 5-hydroxyalkyl-1,2,3-triazoles and 5-quinoxaline-1,2,3-triazole, which provided an entry into structurally diverse 5-functionalized-1,2,3-triazoles. 相似文献
997.
详细探讨采用全印刷工艺,制备聚合物OLED显示屏的工艺流程和技术难点的克服。通过喷墨打印纳米银电子墨水制备金属阴极,完全避免了高温及真空工艺的使用。在显示屏制备过程中,我们成功研发由水/醇溶性共轭聚合物聚[9,9-二辛基芴-9,9-双(N,N-二甲基胺丙基)芴],与一种可固化的环氧树脂粘合剂共混形成的多功能缓冲层。此多功能缓冲层,一方面保护有机功能层,避免纳米阴电子墨水的侵蚀,另一方面提供必需的电子注入功能,使高功函银阴极可以有效地注入电子。通过研究表面能优化打印阴极的成型形貌,并克服工艺难点,所制得的96×3×64分辨率的单色和全彩色聚合物OLED显示屏无坏点/坏线,红、绿、蓝电流效率分别为0.62、4.38、0.93cd/A,色坐标分别为(0.63,0.37)、(0.39,0.57)、(0.18,0.16)。 相似文献
998.
Min-Ming Zou Feng-Juan Zhu Xue Tian Li-Ping Ren Xu-Sheng Shao Zhong Li 《中国化学快报》2014,25(12):1515-1519
An efficient synthetic pathway to 2-oxo-1,2-dihydropyridine-fused 1,3-diaza heterocycles from heterocyclic ketene aminals,phathalic anhydride and ethyl cyanacetate was established.This protocol involved aza-ene reaction/imine-enamine tautomerization/enamine-ester exchange/ring-opening reaction sequence. 相似文献
999.
Ren-Min Wu Na Qi Yu-Wen Jia Zhu Guan Liang-Ren Zhang Li-He Zhang Zhen-Jun Yang 《中国化学快报》2014,25(12):1583-1585
A facile and efficient protocol for the synthesis of sulfur substituted-cyclopyrophosphate of cIDPRE(P_S~1-cIDPRE) was developed.The key step was the cyclization process which was completed by the sulfur substituted cyclization precursor 1b via the one-pot phosphoramidite strategy. 相似文献
1000.
A phthalazinone monomer with an allyl group, i.e. 4-(3-allyl-4-hydroxyphenyl)phthalazin-1(2H)-one, was synthesized and then copolymerized with 4-(4-hydroxylphenyl)(2H)-phthalazin-1-one and 2,6- diflurobenzonitrile by means of aromatic nucleophilic polycondensation to provide a series of crosslinkable poly(aryl ether nitrile)s. The virgin copolymers exhibited good solubility in polar organic solvents with relative high molecular weights (Mw: 45,130-58,403, inherent viscosities: 0.58-0.75 dL/ g). After cross-linking, the thermal stability and solvent resistance of the polymer increased. 相似文献