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排序方式: 共有188条查询结果,搜索用时 10 毫秒
1.
ResearchonCrystalStructureoftheComplexof10-Hydroxy-10-(3-indolyl)-9-phenanthrenonewithTetrahydrofuranMengJi-Ben;WenZhong;Wang... 相似文献
2.
A series of poly(ethylene glycol) biscoumarinyloxyacetatea have been synthesized and their intramolecular photochemical cyclodimerizations have been studied. It was found that only syn-HT configuration products were obtained when these bisesters were directly irradiated in chloroform, and the yields of the products decreased with the increase of the chain length. This photocyclization reaction is a convenient and effective method to synthesize macrocyclic compounds. 相似文献
3.
聚苯胺导电复合物二次掺杂的基材效应 总被引:1,自引:0,他引:1
对十二烷基苯磺酸掺杂的聚苯胺与氯磺化聚乙烯或苯乙烯-丁二烯-苯乙烯三嵌段共聚物形成的复合物的二次掺杂进行了研究。二次掺杂的复合膜经反掺杂后的UV-Vis吸收光谱在580 ̄800nm处呈现宽的吸收,证实了二次掺杂后PAn主链的展开,同时表明PAn在CSPE中的展开较在SBS中更充分,ESR动态测试表明二次掺杂诱导主链的载流子间相互作用有2种方式;PAn/CSPE中的单极化子转变为双极化子;PAn/S 相似文献
4.
This paper describes several highly efficient aza-Baylis-Hillman reactions of N-tosylated imines with MVK, acrolein, and phenyl acrylate or alpha-naphthyl acrylate in the presence of a Lewis base. In most cases, the reaction can be completed within 1 h using the appropriate Lewis base catalyst. An efficient method to synthesize beta-amino ketones, aldehydes and esters in high yields and short reaction time has been developed. 相似文献
5.
5-amino-l,10-phenanthroline (5-AP), as a tautomeric heterocyclic aromatic chelating fluorophore (THACF), can sense Zn^2+ selectively by shifting emission from 495 to 564 nm upon Zn^2+ addition in ethanol. The ratiometric fluorescent sensing behavior has been correlated to the tautomerization of 5-AP affected by solvents and metal chelation. The strategy using THACF as ratiometric fluorescent sensor for Zn^2+ not only simplifies the synthetic procedure but also gives a promising alternative for Zn^2+ ratiometric fluorescent sensor design. 相似文献
6.
The chiral nitrogen Lewis base, tricyclic cinchona alkaloid derivative TQO, is an effective promoter in the catalytic, asymmetric aza‐Baylis–Hillman reaction of N‐sulfonated imines Ar? CH?NR′ 1 (R′ = Ts, Ms, Ns, SES) with various activated olefins such as methyl vinyl ketone (MVK), ethyl vinyl ketone (EVK), acrolein, methyl acrylate, phenyl acrylate, or α‐naphthyl acrylate to give the corresponding adducts in moderate to good yields with good to high ee (up to 99 %) at ?30 °C or 45 °C in various solvents, including DMF/MeCN (1:1, v/v). The first such reaction of 1 with the simplest Michael acceptor MVK and methyl acrylate has been achieved with excellent enantioselectivity. The adducts derived from MVK and EVK had the opposite absolute configuration to those from acrolein, methyl acrylate, phenyl acrylate, and α‐naphthyl acrylate. A plausible mechanism has been proposed on the basis of previous reports and the authors’ investigations. An effective bifunctional chiral nitrogen Lewis base–Brønsted acid system has been revealed in this type of aza‐Baylis–Hillman reaction. 相似文献
7.
Photocycloadditionof(4-methyl-7-coumarinyl)OxyaceticAcidPropanediolDiesterandX-rayCrystalStructureofProductDuDa-Ming;WangYong... 相似文献
8.
Jin Yang Guo-Li Zheng Li Li Fang-Fang Li Yong-Mei Zhang Jing-Fu Liu 《Journal of solid state chemistry》2003,174(1):116-124
A series of divalent transition metal phosphonates containing hydrogen-bonded layers of phosphonate anions, namely [M(phen)3]·C6H5PO3·11H2O [M=Co(1), Ni(2), Cu(3)] and [Cd(phen)3]·C6H5PO3H·Cl·7H2O (4) have been synthesized, structurally characterized by single-crystal X-ray diffraction method. These compounds all crystallize in the triclinic system, space group P-1. The lattice parameters are a=12.1646(5), b=12.4155(6), c=15.4117(10) Å, α=78.216(2), β=79.735(3), γ=77.8380(3)°, V=2205.1(2) Å3, Z=2 for 1; a=12.097(2), b=12.606(3), c=15.742(3) Å, α=76.66(3), β=80.04(3), γ=77.75(3)°, V=2263.4(8) Å3, Z=2 for 2; a=12.058(2), b=12.518(3), c=15.781(3) Å, α=77.77(3), β=80.02(3), γ=77.91(3)°, V=2255.5(8) Å3, Z=2 for 3 and a=12.47680(10), b=12.6693(2), c=16.1504(3) Å, α=82.600(1), β=71.122(1), γ=77.355(1)°, V=2352.37(6) Å3, Z=2 for 4. All structures are refined by full-matrix least-squares methods [for 1, R1=0.0602 using 6458 independent reflections with I>2σ(I); for 2, R1=0.0632 using 4657 independent reflections with I>2σ(I); for 3, R1=0.0634 using 6221 independent reflections with I>2σ(I); for 4, R1=0.0400 using 7930 independent reflections with I>2σ(I)]. In the crystal structures, the phenylphosphonate anions and water molecules are hydrogen-bonded to form layers, and there exist the cationic species [M(phen)3]2+ between the adjacent layers of anions and water. Luminescence, thermal analysis as well as IR spectroscopic studies are also presented. 相似文献
9.
利用遗传算法,并结合线性回归和交叉验证方法,对一系列43个苯并呋喃/噻吩联二苯类PTP1B抑制剂作了二维定量构效关系的研究.计算得到了一组效果较好的定量构效关系模型.模型不仅具有好的回归能力,而且还具有很好的预测能力.同时,通过分析在遗传优化过程中参数在精华种群中所占的比例,还得到了可能对活性影响较大的成分.计算结果表明,分子的4个参数:lgP(分配系数)、Area(表面积)、MW(分子量)以及Dip(偶极距)是影响化合物活性的最重要的参数,这对抑制剂的设计和改造提供了指导. 相似文献
10.