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191.
The ENDOR spectrum of ~(14)N-~(63)Cu-HAP complex in DMSO/EtOH (5:1) freezing solution at 20 K has been studied using orientational selective method in this paper. The anisotropic superhyperfine coupling tensor and qusdrupole coupling tensor of ligand ~(14)N nucleus, and the superhyperfine coupling tensor of various ~1H nuclei have been measured precisely. Comparing the superhyperfine coupling tensor of ~(14)N-nucleus with previous work shows that the analytical method of spectrum is reasonable and the data are reliable in our previous work. 相似文献
192.
Zi-Shu Yang Yuhang Yao Adam C. Sedgwick Cuicui Li Ye Xia Yan Wang Lei Kang Hongmei Su Bing-Wu Wang Song Gao Jonathan L. Sessler Jun-Long Zhang 《Chemical science》2020,11(31):8204
We report here porphodilactol derivatives and their corresponding metal complexes. These systems show promise as “all-in-one” phototheranostics and are predicated on a design strategy that involves controlling the relationship between intersystem crossing (ISC) and photothermal conversion efficiency following photoexcitation. The requisite balance was achieved by tuning the aromaticity of these porphyrinoid derivatives and forming complexes with one of two lanthanide cations, namely Gd3+ and Lu3+. The net result led to a metalloporphodilactol system, Gd-trans-2, with seemingly optimal ISC efficiency, photothermal conversion efficiency and fluorescence properties, as well as good chemical stability. Encapsulation of Gd-trans-2 within mesoporous silica nanoparticles (MSN) allowed its evaluation for tumour diagnosis and therapy. It was found to be effective as an “all-in-one” phototheranostic that allowed for NIR fluorescence/photoacoustic dual-modal imaging while providing an excellent combined PTT/PDT therapeutic efficacy in vitro and in vivo in 4T1-tumour-bearing mice.We report here porphodilactol derivatives and their corresponding metal complexes as “all-in-one” phototheranostics by controlling the relationship between intersystem crossing (ISC) and photothermal conversion efficiency following photoexcitation. 相似文献
193.
194.
A one-pot procedure for the efficient synthesis of a small library of t-RNA inhibitor analogues was developed. Thus,Rh2(OAc)4 catalyzed three-component 1,3-dipolar cycloaddition reactions of carbonyl ylides derived from diazoindan-1,3-dione and aldehydes with other dipolarophiles in 1,1,2,2-tetrachloroethane at 80 ℃ gave ring fused tetrahydrofurans having three stereocenters in good yield. 相似文献
195.
ZHANG Peng-Fei CHEN Zhen-Chu 《有机化学》2003,23(Z1):87-89
During the last few years alkenyl(phenyl)iodonium salts have risen from mere chemical curiosities to valuable synthetic intermediates. [1] Because of an excellent leaving group ability of a phenyliodonyl moiety, alkenyl(phenyl) iodonium salts undergo nucleophilic vinyl substitutions under mild conditions, thus providing a useful route for the synthesis of various kinds of olefins. Recently, some of functionalized alkenyl iodonium salts have been prepared. [2] 相似文献
196.
CHEN Kai ZHU Zhong-liang ZHANG De-jun 《高等学校化学研究》2006,22(4):435-438
IntroductionStudies on reversible kinetic systems are consi-dered as a hotspot of chemical and biochemical kineticresearches[1,2]. Of late, some researches have been fo-cused on the simultaneous optimization of the obverseand reverse rate constants[3,4].H… 相似文献
197.
This communication describes the catalytic asymmetric 1,2-addition of vinylzinc reagents to aromatic, alpha,beta-unsaturated, and dialkyl ketones with enantioselectivities between 79 and 97% and with yields ranging from 84 to 98%. The products of these reactions are tertiary allylic alcohols with chiral quaternary centers that are useful in organic synthesis. The reaction involves hydrozirconation of a terminal alkyne, transmetalation to zinc, and addition to a ketone in the presence of a chiral titanium-based Lewis acid catalyst. The reactions proceed smoothly at room temperature in under 24 h. 相似文献
198.
流动注射电化学发光测定维生素B1的研究 总被引:2,自引:0,他引:2
基于发现在强碱性介质维生素 B1对电生BrO-氧化Luminol的强化学发光有很强的抑制作用, 将在线恒电流电解产生BrO-与流动注射技术结合,建立了流动注射电化学发光测定维生素B1的新方法.该方法测定维生素B1的线性范围为1.0×10-8~6.0×10-6g·ml-1,检出限为3.2×10-9g·ml-1,相对标准偏差为1.2%(n=11).该法具有灵敏度高,可控性强等优点,用于片剂中的维生素B1含量测定,结果满意. 相似文献
199.
离子型溶液聚合速度方程式一般可写成: r=-dM/dθ=kM~mC~n式中M,C分别代表溶液中单体与催化剂的浓度,m,n是两个动力学参数。为了控制聚合过程或设计适当的反应器,必须考虑体系的动力学特性与传热特性的紧密联系。本文 对恒温下分批式聚合操作的各种实施方案进行了讨论。 相似文献
200.
High-energy-density batteries are in urgent need to solve the ever-increasing energy storage demand for portable electronic devices, electric vehicles, and renewable solar and wind energy systems. Alkali metals, typically lithium(Li), sodium(Na) and potassium(K), are considered as the promising anode materials owing to their low electrochemical potential, low density, and high theoretical gravimetric capacities. However, the problem of dendrite growth of alkali metals during their plating/stripping process will lead to low Coulombic efficiencies, a short lifespan and huge volume expansion, eventually hindering their practical commercialization. To resolve this issue, a very effective approach is engineering the anodes on structured current collectors. This review summarizes the development of the alkali metal batteries and discusses the recent advances in rational design of anode current collectors. First, the challenges and strategies of suppressing alkali-metal dendrite growth are presented. Then the special attention is paid to the novel current collector design for dendrite-free alkali metal anodes. Finally, we give conclusions and perspective on the current challenges and future research directions toward advanced anode current collectors for alkali metal batteries. 相似文献