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61.
Chen Sun Ya‐Hui Guo Sha‐Sha Han Jing‐Zhao Li Kuan Jiang Lin‐Feng Dong Qi‐Long Liu Cheng‐Yang Yue Xiao‐Wu Lei 《Angewandte Chemie (International ed. in English)》2020,59(38):16465-16469
Considering the instability and low photoluminescence quantum yield (PLQY) of blue‐emitting perovskites, it is still challenging and attractive to construct single crystalline hybrid lead halides with highly stable and efficient blue light emission. Herein, by rationally introducing d10 transition metal into single lead halide as new structural building unit and optical emitting center, we prepared a bimetallic halide of [(NH4)2]CuPbBr5 with new type of three‐dimensional (3D) anionic framework. [(NH4)2]CuPbBr5 exhibits strong band‐edge blue emission (441 nm) with a high PLQY of 32 % upon excitation with UV light. Detailed photophysical studies indicate [(NH4)2]CuPbBr5 also displays broadband red light emissions derived from self‐trapped states. Furthermore, the 3D framework features high structural and optical stabilities at extreme environments during at least three years. To our best knowledge, this work represents the first 3D non‐perovskite bimetallic halide with highly efficient and stable blue light emission. 相似文献
62.
Akshita Khandelwal Danish Khan Jyoti Kuntail Indrajit Sinha 《International journal of quantum chemistry》2024,124(1):e27237
Reducing p-nitrophenol (PNP) to p-aminophenol is an industrially relevant synthesis. Nevertheless, only a few heterogeneous catalysts have been evaluated for the reduction of PNP by glycerol. Appropriate quantum computational studies can screen potential catalysts for this crucial green reaction. The present research investigates the catalytic activities of Pd@Ag and Ni@Ag core-shell nanogeometries toward PNP reduction by glycerol through density functional theory (DFT) calculations. The central atom of a geometry-optimized 13-atom Ag cluster was replaced by Pd and Ni atoms to create the core-shell morphologies. The interaction energies of PNP and glycerol with each of the (metal/bimetallic) clusters were evaluated by DFT calculations to find the best PNP and glycerol molecule orientation with the respective bimetallic cluster. Electrostatic potential surface and natural bond orbital analyses were performed to study the charge distribution and transfer between atomic orbitals. The frequencies of vibrational modes in isolated PNP/glycerol structures were compared to those when these molecules were in the presence of the different metal clusters to infer the effect of the interactions. All performed analyses indicated improved catalytic activity toward PNP reduction by glycerol upon Ni-doping of the Ag13 cluster. 相似文献
63.
64.
Vasina T. V. Masloboishchikova O. V. Khelkovskaya-Sergeeva E. G. Kustov L. M. Zeuthen P. 《Russian Chemical Bulletin》2002,51(2):255-258
The activity of monometallic Rh and Pt catalysts and bimetallic Pt—Rh catalysts on oxide supports in cyclohexane ring opening to form n-hexane was studied. The Rh-containing catalysts are highly active and selective in this reaction. Cyclohexane dehydrogenation predominates in the case of the Pt catalysts. The use of the bimetallic alumina-supported Pt—Rh catalysts allows one to minimize the contribution of cyclohexane cracking and to enhance the selectivity for n-hexane with the yield of the latter slightly depending on the metal ratio in the bimetallic system under the experimental conditions. 相似文献
65.
用TPR和XPS和ZnO负载Ni-Cu双金属催化剂中Ni与Cu的相互作用进行了研究。TPR结果表明,Ni-Cu双金属催化剂中,Cu在低温下还,而Ni在高温下还原,还原的Cu能促进Ni的还原。 相似文献
66.
1 INTRODUCTION Over the last decade, there has been continuous interest in cyanide-bridged lanthanide-transition me- tal complexes due to their extensive applications in preparing rare earth orthoferrites[1], chemical sensor materials[2], fluorescent ma… 相似文献
67.
报道了多核Nd-Al双金属配合物活性体对共轭双烯烃的溶液聚合。结果表明,适宜的振荡时间有利于提高活性体的催化活性;通过外加A1Et3,验证了聚合体系的纯度和活性体的稳定性。溶剂类型对活性和聚合物分子量影响较大,活性次序为甲苯≥环己烷>正己烷;对产物[η》的影响则相反:甲苯<<环己烷<正己烷。不同单体的定向聚合性能有差别,聚丁二烯的顺1,4含量较低,且易受反应条件的影响。 相似文献
68.
The reactions of the mixed metal cluster complexes PtRu5(CO)16(μ6-C)[Pt(PBu
)], 5 and PtRu5(CO)16(μ6-C)[Pt(PBu
]2, 6 with selected alkynes have been investigated. Compound 5 adds one and two equivalents of PhC2H to yield the new compounds PtRu5(CO)15(μ6-C)(μ3-PhC2H)[Pt(PBu
)], 8 and PtRu5(CO)
-C)(
-PhC2H)2[Pt(PBu
)], 9 at 40 and 68°C, respectively. Compound 6 was found to react with PhC2H at 40°C to yield the new compound PtRu5(CO)
-C)(
-PhC2H)[Pt(PBu
)]2, 10. The reaction of 6 with PhC2Ph at 97°C yielded the new compound PtRu5(CO)
-C)(
-PhC2Ph)2[Pt(PBu
)]2, 11. All products were characterized crystallographically by single crystal X-ray diffraction techniques. The structure of 8 consists of a pseudo-octahedral PtRu5 cluster with a second platinum atom bridging a basal edge of the Ru5 square pyramid. A triply bridging PhC2H ligand is bonded to the two platinum atoms and one of the ruthenium atoms. The structure of 9 consists of a nido-dodecahedral Pt2Ru5 cluster with a carbido ligand in the interior that is not bonded to all seven of the metal atoms. It also contains two triply
bridging PhC2H ligands. The structure of 10 consists of a central octahedral cluster of five ruthenium atoms and one platinum atom. Two additional platinum atoms are
bonded to the platinum atom in this cluster but these atoms are not bonded to any other metal atoms of the PtRu5 cluster. A triply bridging PhC2H ligand is coordinated to the group of three platinum atoms. The structure of 11 consists of an octahedral PtRu5 cluster with two additional platinum atoms capping two PtRu2 triangular faces. There are two PhC2Ph ligands bridging two Ru3 triangular faces of the central octahedron.
This report is dedicated to Professor Ilya Moiseev on the occasion of his 75th birthday for his many pioneering contributions
to the chemistry of metal clusters. 相似文献
69.
70.
Guanlin Li Ling Zhao Yicong Luo Youbin Peng Kai Xu Dr. Xiaohong Huo Prof. Dr. Wanbin Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(24):e202200273
Asymmetric desymmetrization has been demonstrated to be a powerful strategy for building stereocenters in asymmetric synthesis. Herein, a Pd/Cu catalyzed asymmetric desymmetrization reaction with a simple geminal dicarboxylate is reported. A wide scope of imino esters bearing an aryl or heteroaromatic group were compatible with this bimetallic catalytic system. The reactions proceeded smoothly, giving the desired products in good yields with high to excellent regio-, diastereo-, and enantioselectivity (up to 20 : 1 branched:linear, >20 : 1 dr, >99 % ee). Notably, the reaction favored branched selectivity, which is unusual for the Pd-catalyzed allylic alkylation reaction. In addition, the standard product could be easily transformed to other valuable molecules such as chiral allylic alcohols, carbamates, and organic boron compounds. Furthermore, DFT calculations were conducted to explain the origin of the branched selectivity. 相似文献