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981.
Wu  Chengyi  Wang  Liping  Kang  Huiting  Dan  Youmeng  Tian  Dating  Zheng  Yin 《Research on Chemical Intermediates》2020,46(2):1437-1451
Research on Chemical Intermediates - Biomass waste, which was the by-product generated along with the production of food, was transformed into high-value constituent in slow-release fertilizers....  相似文献   
982.
In order to further explore the detailed reaction mechanism of carbon dioxide activated by [Re(CO)2]+ complex, CCSD(T) methods was performed to determine related potential energy surface (PES). Crossing point is determined by using a partially optimized method. The result shows that larger spin-orbital coupling (155.37 cm−1) and intersystem crossing probabilities in spin-forbidden region causes the electron to spin flip at the minimum energy crossing point and access to the lower singlet PES. Nonadiabatic rate constant k is estimated to be quite rapid, so transition state (1TS1) is rate-controlled steps. In addition, the electronic structure of oxygen-atom transfer process is further analyzed by localized molecular orbital and Mayer bond order. The analysis finds that the form of main bonding orbital is the electron contribution from the p(O) in CO2 to the empty d(Re) orbital.  相似文献   
983.
A nickel‐catalyzed conjunctive cross‐coupling of alkenyl carboxylic acids, aryl iodides, and aryl/alkenyl boronic esters is reported. The reaction delivers the desired 1,2‐diarylated and 1,2‐arylalkenylated products with excellent regiocontrol. To demonstrate the synthetic utility of the method, a representative product is prepared on gram scale and then diversified to eight 1,2,3‐trifunctionalized building blocks using two‐electron and one‐electron logic. Using this method, three routes toward bioactive molecules are improved in terms of yield and/or step count. This method represents the first example of catalytic 1,2‐diarylation of an alkene directed by a native carboxylate group.  相似文献   
984.
A nanocage coupling effect from a redox RuII‐PdII metal–organic cage (MOC‐16) is demonstrated for efficient photochemical H2 production by virtue of redox–guest modulation of the photo‐induced electron transfer (PET) process. Through coupling with photoredox cycle of MOC‐16, tetrathiafulvalene (TTF) guests act as electron relay mediator to improve the overall electron transfer efficiency in the host–guest system in a long‐time scale, leading to significant promotion of visible‐light driven H2 evolution. By contrast, the presence of larger TTF‐derivatives in bulk solution without host–guest interactions results in interference with PET process of MOC‐16, leading to inefficient H2 evolution. Such interaction provides an example to understand the interplay between the redox‐active nanocage and guest for optimization of redox events and photocatalytic activities in a confined chemical nanoenvironment.  相似文献   
985.
Shi  S. K.  Kang  R. Q.  Li  J. L.  Bai  Y.  Dang  D. B. 《Russian Journal of Coordination Chemistry》2020,46(7):513-520
Russian Journal of Coordination Chemistry - A new V-centered Keggin polyoxometalate-based inorganic-organic hybrid (HPpz)3[VW12O40] (I) (Ppz = piperazine) has been hydrothermal synthesized and...  相似文献   
986.
A de novo first collective total synthesis of 11‐deoxylandomycins is reported. A signature step is featured by the Pd‐catalyzed asymmetric addition of alcohol to ene‐alkoxyallenes that assembles oligomeric 2,3,6‐trideoxyoligosaccharides. The unique feature of the protocol is illustrated by a flexible access to various natural 11‐deoxylandomycins as well as non‐natural analogues.  相似文献   
987.
The high‐dimensional (that is, three‐dimensional (3D)) assembly of nanomaterials is an effective means of improving their properties; however, achieving this assembly at the atomic level remains challenging. Herein, we obtained a novel nanocluster, [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl (Dppp=1,3‐bis(diphenylphosphino)propane) showing a 3D octameric assembly mode involving the kernel penetration of eight complete icosahedral Au@Ag10Au2 units for the first time. The atomically precise structure was determined by single‐crystal X‐ray diffraction, and further confirmed by thermogravimetric analysis, X‐ray photoelectron spectroscopy, and electrospray ionization mass spectrometry measurements. Furthermore, ligand‐induced transformation prompted the conversion of [Au8Ag57(Dppp)4(C6H11S)32Cl2]Cl, with complete octameric fusion into [Au8Ag55(Dppp)4(C6H11S)34][BPh4]2, with incomplete octameric fusion. These observations will hopefully facilitate further research on the assembly of M13 nanobuilding blocks.  相似文献   
988.
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990.
Clarification of the quality and biological effect equivalence of traditional Chinese medicines containing multi‐origin species is essential to improve their current quality standards, and also is the core problem to clarify the origins of single herbs with multi‐species in Chinese formulas that will guarantee their clinical application. Huangqin decoction is the typical one of multi‐origin formulas frequently used in traditional Chinese medicine and Kampo medicine. An ultra high performance liquid chromatography with electrospray ionization–tandem mass spectrometry was developed for chemical profiling and marker quantification of Huangqin decoction prepared with two different original types of peony root, white and red peony root. Forty‐seven main peaks in chemical profiling of Huangqin decoction prepared with white and red peony root were identified: nine were from peony root, 20 from baical skullcap root, 17 from licorice root, and one from jujubae fruit. The markers characteristics of the respective types of peony root in Huangqin decoction differ from that in single herbs, especially in terms of monoterpenoids and hydrolysable tannins. Subsequently, 17 representative markers in Huangqin decoction prepared with three types of peony root and their chemical characteristics and content distribution were carried out.  相似文献   
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