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71.
合成了2个基于氮氧自由基配体且结构类似的双核配位化合物,其分子式分别为[Mn2(hfac)4(NIT-mo-pmy)2](1)和[CO2(hfac)4(NIT-mo-pmy)2](2),其中hfac=六氟乙酰丙酮,NIT-mo-pmy=2-(2-甲氧基-5′-嘧啶基)-4,4,5,5-四甲基咪唑啉基-3-氧-1-氧自由基。2个配合物均属于三斜晶系P1空间群,其双核配位单元进一步构筑为中心对称的平行四边形分子阵列。变温磁化率的测试表明,在2个配合物中,中心离子和氮氧自由基单元之间存在反铁磁交换作用。借助构效关系研究,分析了磁作用强度的差异。通过适当近似的磁化学模型,对Mn(Ⅱ)配合物的磁性行为进行了定量拟合,并与相关化合物磁作用强度进行了比对、分析。 相似文献
72.
Jia Sun Peicheng Zhang Qi Wei Hang Xun Feng Tang Yongde Yue Li Li Xuefeng Guo Rong Zhang 《Tetrahedron letters》2014
Amarusine A (1), a new polyketide derivative possessing an unusual dioxaspiro[4.4]nonane derivative with a butyrolactone ring, was isolated from the leaves of Pleioblastus amarus. The structure and absolute stereochemistry of compound 1 were rigorously determined using UV, IR, HRESIMS, and 1D and 2D NMR techniques and by comparing experimental and calculated electronic circular dichroism (ECD) spectra. Amarusine A (1) exhibits a good antioxidant activity for scavenging the DPPH radical. A possible biosynthetic pathway was postulated. 相似文献
73.
Wu Lei Su Huijuan Liu Qi Sun Libo Sun Xun Zhao Lijun Qi Caixia 《Kinetics and Catalysis》2022,63(5):498-504
Kinetics and Catalysis - Using a modified deposition-precipitation method, a series of Au–Mo/ZSM-5 catalysts with different Au loadings were prepared. The XRD, nitrogen adsorption-desorption,... 相似文献
74.
The redox-mediated electrochemical–chemical process, when it involves the redox-targeting reaction with energy materials, has shown intriguing potential for various energy-related applications. This review starts with a brief discussion on the evolution of redox-targeting reactions for high-energy redox-flow batteries and the critical future studies for large-scale energy storage. Then, with spatially decoupled water electrolysis as an example, the merits of redox-targeting reaction by liberating the catalyst from electrode surface are highlighted, followed by an introduction of redox targeting–based thermal-to-electrical conversion. We have also featured various redox-targeting processes in other fields of study, such as electrochromic window, redox catalysis, and spent battery material recycling. Overall, this review attempts to demonstrate the incredible versatility and prospects of redox-targeting process for energy-related applications. 相似文献
75.
76.
Hao Huang Cuicui Du Hongyan Shi Xun Feng Jin Li Yanlei Tan Wenbo Song 《Particle & Particle Systems Characterization》2015,32(1):72-79
Uniform water‐soluble monolayer MoS2 quantum dots (MQDs) with lateral sizes of ≈2.1 nm, a clearly zigzag‐terminated edge, and a hexagonal lattice structure are achieved using ammonium molybdate, thiourea, and N‐acetyl‐l ‐cysteine (NAC) as precursors and the capping reagent in a facile one‐pot hydrothermal approach. MQDs have good dispersity and high stability in aqueous suspension and exhibit a significantly larger direct bandgap (3.96 eV) compared to monolayer MoS2 nanosheets (1.89 eV). Pronounced blue‐shifts in the wavelengths of both the excitonic absorption and intrinsic state emission with activated strong luminescence at room temperature beyond monolayer MoS2 nanosheets is demonstrated. Unusual upconversion photoluminescence is also observed and is caused by two successive transfers of energy from the near‐infrared (NIR) absorption generated by the NAC capping reagent to the hexagonal structure of MQDs. Additional optical properties of MQDs may provide numerous exciting technological applications. Here, MQDs are demonstrated as a highly selective fluorescent reagent for detecting tetracycline hydrochloride under UV and NIR irradiation. 相似文献
77.
78.
在低As压条件下退火处理原子级平坦的GaAs(001) βup 2(2×4)重构表面. 利用扫描隧道显微镜对表面进行研究, 发现随着低As压退火时间的延长, 表面形貌与表面重构的演变同步进行. 表面形貌经历了从有序平坦转变为无序平坦, 然后逐渐恢复到有序平坦状态的过程. 表面重构则由βup 2(2×4)重构逐渐转变为(2×6)重构, 然后再转变为锯齿状的(2×6)重构, 并且表面形貌与表面重构的演变存在一定的相互关系. 相似文献
79.
KH2PO4 single crystals were grown in aqueous solution at different pH values by using “point seeds” with a defined crystallographic direction at 59 degree to the Z axis. Atomic Force Microscope (AFM) was applied to observe the surface morphology of (100) face. It was found that at the same supersaturation, the larger steps appeared at the lower pH value before appearance of 2D nucleus. We found that 2D nucleus was occurred at σ ≤ 0.04 when pH value is <2.8. The occurrence of 2D nucleus was caused by the decreasing step‐edge free energy with the decreasing of pH value in the growth solution. In this paper, we observed the morphologies of (100) faces of KDP crystals which grew in solutions with different pH values. 2D nucleuses appeared on the terrace of growth steps when pH value down to 2.8 and 3.2 at supersaturation of 0.04, while pH value down to 2.4, only 2D nucleation control the growth. Therefore, the pH value can change the growth mechanism of KDP crystals. 相似文献
80.
Biao Xu Peilei He Huiling Liu Pengpeng Wang Prof. Dr. Gang Zhou Prof. Dr. Xun Wang 《Angewandte Chemie (International ed. in English)》2014,53(9):2339-2343
Multidimensional nano‐heterostructures (NHSs) that have unique dimensionality‐dependent integrative and synergic effects are intriguing but still underdeveloped. Here, we report the first helical 1D/2D epitaxial NHS between CdS and ZnIn2S4. Experimental and theoretical studies reveal that the mismatches in lattice and dangling bonds between 1D and 2D units govern the growth procedure. The resulting well‐defined interface induces the delocalized interface states, thus facilitate the charge transfer and enhance the performance in the photoelectrochemical cells. We foresee that the mechanistic insights gained and the electronic structures revealed would inspire the design of more complex 1D/2D NHSs with outstanding functionalities. 相似文献