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991.
A Pd-catalyzed coupling of haloalkynes with allyl acetate has been reported, providing a convenient method for the stereoselective synthesis of (Z)-β-haloenol acetates in good yields. The synthetic utility of this method is demonstrated by the formation of functionalized enol acetates via the Suzuki-Miyaura or Sonogashira coupling of the resulting (Z)-β-haloenol acetate products. 相似文献
992.
Liu X Xu D Lu R Li B Qian C Xue P Zhang X Zhou H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(5):1660-1669
A series of new triphenylamine-functionalized bis(β-diketone)s bridged by a carbazole (CnBDKC, n=1, 4, 8, 16) with twisted intramolecular charge-transfer emission in polar solvents has been synthesized. The length of the carbon chains has a significant effect on the self-assembling properties of the compounds. Well-defined 1D nanowires were easily generated from C1BDKC with a methyl group by a reprecipitation approach directed by π-stacking interaction, and the molecules packed into J-aggregates in the nanowires. In addition, 1D nanofibers based on C16BDKC bearing a long hexadecyl chain were prepared through the organogelation process, and H-aggregates were formed driven by the synergistic effect of π-stacking interaction and van der Waals force in the gel phase. C4BDKC and C8BDKC containing butyl and octyl side chains, respectively, cannot arrange into dispersed nanostructures, probably because π-π interaction between conjugated moieties might be disturbed by the interaction between the side chains, which is, however, not strong enough to dominate the self-assembling process. Notably, the nanowires based on C1BDKC and the gel nanofibers from C16BDKC can emit strong green light under irradiation, which suggests that these 1D nanomaterials may have potential applications in emitting materials as well as photonic devices. 相似文献
993.
铜(Ⅱ)-三氮唑偶氮络合物与脱氧核糖核酸相互作用的电化学行为 总被引:5,自引:0,他引:5
运用电化学方法研究了铜(Ⅱ)-三氮唑偶氮(2-[2,3,5-三氮唑偶氮]-5-二甲氨基苯甲酸,TZAMB)络合物与脱氧核糖核酸(DAN)的相互作用。在pH2.5(0.05mol/L)邻苯二甲酸氢钾(PBS)缓冲溶液中,DNA与Cu(Ⅱ)-TZAMB络合物形成一种电惰性结合物,使Cu(Ⅱ)-TZAMB络合物的还原峰电流减小。通过循环伏安法、盐效应以及紫外-可见吸收谱证实了是由Cu(Ⅱ)-TZAMB络合物与DNA形成一种插入式的电惰性结合物而使其峰电流下降。根据这种峰电流下降可以测定DNA,测定结果令人满意。 相似文献
994.
单分散聚苯乙烯微球的制备及影响因素研究 总被引:11,自引:2,他引:11
以聚乙烯吡咯烷酮为分散剂,无水乙醇为反应介质,偶氮二异丁腈为引发剂,采用分散聚合工艺,通过优化反应条件,制备出了粒径为5μm单分散(分散系数≤5%)聚苯乙烯微球。所制备的聚苯乙烯微球标准偏差δ=0.16μm,分散系数ε=0.02,且具有良好的球形度,表面非常光滑,无破损,无缺损。对影响单分散聚苯乙烯微球的因素进行了研究,结果表明:随着分散稳定剂用量的增加,聚苯乙烯微球的粒径减小;随着单体和引发剂用量的增加,聚苯乙烯微球的粒径增大。分散稳定剂和单体用量是影响聚苯乙烯微球粒径分布的两个主要因素。 相似文献
995.
2,4,6-三硝基苯酚改性锆铝复合氧化物固定相分离富勒烯的色谱性能研究 总被引:1,自引:0,他引:1
制备了用于分离C60和C70的2,4,6-三硝基苯酚改性锆铝复合氧化物高效液相色谱固定相,考察了流动相中甲苯的含量、柱温及流速对C60和C70分离的影响,同时比较了酸腐蚀前后锆铝复合氧化物基质对分离的影响,结果表明,2,4,6-三硝基苯酚改性酸腐蚀后锆铝复合氧化物填料对富勒烯表现出较强的分离能力,具有作为富勒烯制备分离的潜力。 相似文献
996.
Three heterometallic cubane-like clusters, [Mo3(mu 3-O)(mu 3-S)3(SnCl3)(dtp)3(py)3] (dtp = S2P(OC2H5)2-, py = C5H5N) (1), (PPN)[Mo3(mu 3-O)(mu 3-S)3(SnCl3)(dtp)3(mu-OAc)(py)] (OAc = CH3COO-, PPN = (C6H5)3PNP(C6H5)3+) (2), and (Et4N)[Mo3(mu 3-O)(mu 3-S)3(SnCl3)(dtp)2(mu-OAc)2(py)] (3) have been prepared by the reaction of [Mo3(mu 3-O)-(mu-S)3(dtp)4(H2O)] (4), [Mo3(mu 3-O)(mu-S)3(dtp)3(OAc) (py)] (5), and [Mo3(mu 3-O)(mu-S)3(dtp)2(OAc)2 (py)] (6) with SnCl2, respectively. They have been characterized by IR, UV-vis, 31P NMR, 95Mo NMR, and X-ray structure analysis. All of these heterometallic clusters have a [Mo3OS3Sn]6+ core but contain a different arrangement of peripheral ligands. As far as the neutral cluster 1 is concerned, there is no bridging OAc ligand, while only one bridging OAc ligand is observed for cluster 2 and two are for cluster 3. The Mo-Mo distances are about 0.03-0.04 A shorter than those of the starting trimolybdenum clusters. This indicates that the incorporation of SnCl3- fragment into (Mo3) clusters makes the Mo-Mo bonding enhanced. Crystal data for 1: triclinic, space group P-1, a = 10.7423(2) A, b = 14.0357(1) A, c = 16.9346(2) A, alpha = 84.054(1) degrees, beta = 87.095(1) degrees, gamma = 84.517(1) degrees, V = 2525.82(6) A3, Z = 2, R = 0.038 for 5584 reflections (I > 2.0 sigma(I)). Crystal data for 2: triclinic, space group P-1, a = 12.9529(1) A, b = 15.6324(2) A, c = 19.6355(1) A, alpha = 92.083(1) degrees, beta = 97.908(1) degrees, gamma = 110.337(1) degrees, V = 3677.41(6) A3, Z = 2, R = 0.034 for 8665 reflections (I > 2.0 sigma(I)). Crystal data for 3: monoclinic, space group P2(1)/n, a = 14.0852(5) A, b = 15.1324(5) A, c = 23.2691(7) A, beta = 97.371(1) degrees, V = 4918.7(3) A3, Z = 4, R = 0.049 for 4970 reflections (I > 2.0 sigma(I)). 相似文献
997.
A novel mixed‐tribridged dimolybdenum(I) compound [Bn4N][Mo2(μ‐SPh)2(μ‐Cl)(CO)6] (1) has been synthesized from the reaction of Mo2(CO)3(SPh)2 with BU4NCl. Compound 1 was characterized by IR, UV‐Vis and 1H, 13C, 95Mo NMR spectroscopic analyses. The electrochemical behavior was measured by cyclic voltammetry, indicating a quasi‐reversible two‐electron transfer in one step. The crystal structure determined by X‐ray crystallography shows that 1 contains a [Mo2(μ‐S)2(μ‐Cl)]? core with a planar Mo2S2unit and a Cl bridge. The Mo? Mo distance is 0.28709(7) nm, and the Mo‐Cl‐Mo angle is 66.44(4)°. A newface‐sharing bioctahedral structure is discussed. 相似文献
998.
从通识教育的时代要求和化学的学科地位出发,首先讨论了在化学类通识课程建设中引入跨学科视角的意义和可操作性。随后以通识课"化学与社会"的建设为例,系统地分享了引入跨学科视角后的课程设计理念和内容框架建设,通过课堂实施方案的论述和特色实例的分享总结了课程实施经验,并以学生访谈资料分析讨论了课程取得的效果和需要进一步完善的方向。以期为跨学科理念在化学教育教学实践中的转化和落地开拓思路、提供经验。 相似文献
999.
以氧化石墨烯为载体,单原子铂(Pt)为活性组分,利用化学还原法制备了单原子Pt/rGO催化剂,用在催化氧化一氧化碳(CO)反应中。通过透射电子显微镜、扫描电子显微镜、球差电镜、傅里叶红外光谱仪对单原子Pt催化剂进行表征。考察了金属负载量、反应温度对催化剂性能的影响,利用气相色谱对CO氧化反应性能进行评价。此次实验包含催化剂的制备、表征和性能测试,实验难度适中,贴近科研前沿,可以让学生体验一个综合的科研过程,激发学生的科研兴趣,培养学生的科研能力。 相似文献
1000.
Dr. Jinpeng Liu Dr. Nali Zhu Dr. Haiming Xu Jinwu Bai Dr. Chaofeng Shao Prof. Meiting Ju Prof. Qilin Yu Prof. Lu Liu 《ChemistryOpen》2019,8(10):1309-1315
Bismuth oxybromide (BiOBr) nanosheets are exciting photocatalysts for microbial disinfection and organic dye degradation. However, it remains a great challenge to easily recycle these nanomaterials and improve their photocatalytic ability. Herein, we constructed a novel photocatalytic BiOBr@PAG gel containing BiOBr nanosheets and polyacrylamide gel (PAG), based on peroxydisulfate-induced polymerization reaction. The photocatalytic gel had equally distribution of BiOBr nanosheets on the surface, and could be easily recycled from water. More strikingly, the gel could also rapidly kill all tested pathogenic bacteria (i. e., Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) under irradiation. Its disinfection activity is attributed to remarkable intracellular ROS production and oxidative cell damage. Furthermore, the gel had higher photocatalytic activity than BiOBr nanosheets alone during degradation of organic dyes. This study developed a novel strategy for preparation of easy-recycling and high-efficiency photocatalytic systems for practical application in environmental treatment and medicinal disinfection. 相似文献