Nanocrystal Arrested Precipitation in Supercritical Carbon Dioxide
作者:Parag S. Shah、Shabbir Husain、Keith P. Johnston、Brian A. Korgel
DOI:10.1021/jp011815c
日期:2001.10.1
perfluorooctanethiol ligands, which bind to the surface of the metal agglomerates and quench particle growth. The ligands are sufficiently solvated by CO2 to provide a steric barrier to uncontrollable aggregation during synthesis. The particles redisperse in acetone and fluorinated solvents. The dominant mechanism to particle growth is through cluster agglomeration followed by ligand passivation, leading to self-similar
在超临界 (sc)-CO2 中,通过从可溶性有机金属前体中捕获沉淀来合成直径为 20 到 120 埃的碳氟化合物涂层银、铱和铂纳米晶体。该合成是通过在 60 至 100 °C 的高温下用 H2 还原在单一 CO2 相中进行的。前体降解和颗粒成核在稳定的全氟辛硫醇配体存在的情况下发生,该配体结合到金属附聚物的表面并淬火颗粒生长。配体被 CO2 充分溶剂化,从而为合成过程中的不可控聚集提供空间屏障。颗粒再分散在丙酮和氟化溶剂中。粒子生长的主要机制是通过簇团聚,然后是配体钝化,导致自相似尺寸分布,标准偏差为 ±47%。此外,纳米晶体尺寸可随前体浓度调节,较高的前体负载量会导致 L…
Selective Co‐Encapsulation Inside an M
<sub>6</sub>
L
<sub>4</sub>
Cage
作者:Stefan H. A. M. Leenders、René Becker、Tatu Kumpulainen、Bas de Bruin、Tomohisa Sawada、Taito Kato、Makoto Fujita、Joost N. H. Reek
DOI:10.1002/chem.201603017
日期:2016.10.17
co‐encapsulation of a variety of combinations of metal complexes and aromatic guests, leading to several ternary complexes. These experiments demonstrate that the efficiency of formation of the ternary complexes depends on the individual components. Moreover, selective exchange of the components is possible, leading to formation of the most favorable complex. Besides the obvious size effect, a charge‐transfer
人们对分子封装产生了广泛的兴趣,因为此类系统可用于稳定客体,促进空腔内的反应,或在有限的空间内引起能量转移过程。需要详细了解封装事件以促进功能性分子封装。在这篇文章中,证明了只有在芳香族化合物作为第二客体存在的情况下,Ir 和 Rh-Cp 型金属配合物才能被封装在自组装的 M 6 L 4金属络合物中。单独的客人没有被封装起来,这表明只有一对客人才能填补笼子的空隙。因此,观察到选择性共封装。这一原理通过金属配合物和芳香客体的多种组合的共封装得到了证明,从而产生了几种三元配合物。这些实验表明,三元复合物的形成效率取决于各个组分。此外,组分的选择性交换是可能的,导致形成最有利的复合物。除了明显的尺寸效应之外,电荷转移相互作用也可能促成这种效应。通过紫外/可见分光光度法可以清楚地观察到电荷转移带。封装电子供体氧化电位的变化也会导致电荷转移能带的变化。正如预期的那样,具有较高氧化电位的金属配合物会产
Characterization of RuO2 and IrO2 films deposited on Si substrate
作者:P.C. Liao、Y.S. Huang、K.K. Tiong
DOI:10.1016/s0925-8388(00)01403-1
日期:2001.4
RuO2 and IrO2 films, deposited on Si substrates hy metal-organic chemical vapor deposition (MOCVD) method and reactive sputtering method under various conditions, were characterized by atomic force microscopy (AFM), X-ray diffraction, electrical conductivity, ellipsometry and Raman scattering measurements. The average grain sizes of the films were estimated by AFM. A grain boundary scattering model was used to fit the relation between the average grain size and electrical resistivity. The optical and dielectric constants were determined by the ellipsometry measurements. The results of the electrical and optical studies show a metallic character of the films deposited at higher temperatures. The red shift and broadening of the line width of the Raman peaks were analyzed and discussed. (C) 2001 Elsevier Science B.V. All rights reserved.
Growth and characterization of iridium dioxide nanorods
We report the results of the synthesis Of IrO2 nanocrystals (NCs) on sapphire (SA) substrates with different orientations via metal-organic chemical vapor deposition (MOCVD) using (MeCp)(COD)Ir as the source reagent. The surface morphology and structural properties of the as-deposited NCs were characterized using field emission scanning electron microscopy (FESEM), and X-ray diffractometry (XRD). FESEM micrographs reveal that vertically aligned NCs were grown on SA(1 0 0), the NCs on SA(0 1 2) and SA(I 10) contained, respectively, single- and double-aligned directions with a tilt angle of 35 degrees from the normal to the substrates, while NCs parallel in-plane alignment were gown on SA(0 0 1). The XRD results indicate that the lrO(2) NCs are (0 0 1), (10 1), and (10 0) oriented on SA(1 0 0), SA(0 1 2)/SA(1 10) and SA(0 0 1) substrates, respectively. A strong substrate effect on the alignment of the lrO(2) NCs growth has been demonstrated and the probable mechanism for the formation of the NCs is discussed. (C) 2007 Elsevier B.V. All rights reserved.