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Onion-Like Inorganic Fullerenes from a Polyhedral Perspective
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
Ch. Chang, A. B. C. Patzer, D. Sülzle, H. Bauer
The pivotal molybdenum Mo132 cage can be written more specifically as [(Mo)Mo5]12[Mo2]30. It consists of 12 fundamental pentagonal [(Mo)Mo5] building blocks with a central Mo atom that are linked together by 30 [Mo2] units. A closer look by taking the oxygen atoms into account reveals that the central Mo atom of the pentagonal [(Mo)Mo5] unit in fact lies at the center of a pentagonal bipyramid (MoO7), while the adjacent five Mo atoms are at the centers of edge-sharing octahedrons (MoO6). Thus, the whole cage system represents a complex arrangement of intermingled shells spanned by molybdenum and several nonequivalent oxygen atoms as well as shells generated by the atoms of the ligand groups (SO4, H2O).
Fluorescent silicon clusters and nanoparticles
Published in Klaus D. Sattler, Silicon Nanomaterials Sourcebook, 2017
The FELIX free electron laser source provides intense and tunable infrared radiation including in the spectral range from 166 to 600 cm−1 where silicon clusters absorb. Vibrational spectroscopy of small silicon cluster cations was performed using multiple photon dissociation spectroscopy. The ions were analyzed in a time-of-flight mass spectrometer. Also, isotopically selected 129Xe atoms were attached to the clusters. Absorption of multiple IR photons would lead to a depletion of the ion signal, allowing the requisition of spectra of size-selected clusters. Comparison of the spectra with calculations using density functional theory (DFT) revealed novel structures and a growth motif that started with a pentagonal bipyramid building block and changed to a trigonal prism for larger clusters (Lyon et al. 2009).
Extracellular Biomineralization and Synthesis of Gold and Platinum Nano- and Microcrystals in Polysaccharide Aqueous Solutions
Published in Victor M. Starov, Nanoscience, 2010
V. R. Estrela-Llopis, T. I. Borodinova, I. N. Yurkova
Thus, in Ref. [138] gold monocrystals have been obtained as a result of microwave irradiation (1000 W, 30–45 seconds) in mixtures of aqueous solutions of HAuC14 and monosugars-a-D-glucose, sucrose, and maltose. In Ref. [139], gold nanocrystals of pentagonal bipyramid geometry have been obtained on the base of the combination of seed-mediated growth method and the polyol method (with PVP as stabilizer) with high yield of pentagonal shape (80%-90%), as a result of ultrasound treatment (70 W, 20 kHz), with temperature rising up to 100°C.
Dissimilarity measure of local structure in inorganic crystals using Wasserstein distance to search for novel phosphors
Published in Science and Technology of Advanced Materials, 2021
Shota Takemura, Takashi Takeda, Takayuki Nakanishi, Yukinori Koyama, Hidekazu Ikeno, Naoto Hirosaki
In this approach, W can be calculated as the local structures with different coordination numbers because the local structures are expressed as the distance distribution. To calculate W of the local structures with the different coordination numbers, seven kinds of ideal structures were selected: tetrahedron, trigonal bipyramid, octahedron, pentagonal bipyramid, cubic, square antiprism, and cuboctahedron. The center-ligand distances are the same in each ideal structure. Table 1 shows W of the seven kinds of ideal structures. The W between pentagonal bipyramid and square antiprism is the smallest at 0.067, but pentagonal bipyramid and square antiprism are dissimilar because the value is larger than 0.047 in Figure 2. Local structures with different coordination numbers indicate dissimilarity. Therefore, this quantitative dissimilarity can be calculated for any local structure, and a local structure with a different coordination number is dissimilar spontaneously.
Synthesis, characterization, crystal structure, thermal analysis of a new co-crystal supramolecular dinuclear zinc (II) complex containing chelidamate ligand
Published in Inorganic and Nano-Metal Chemistry, 2018
Zohreh Derikvand, Azadeh Azadbakht, Behroz Notash
We have synthesized and characterized a new co-crystal supramolecular compounds (dapH)2(hypydcH)2· [Zn2(hypydc)2(H2O)6]·2H2O with chelidamic acid and 3,4-diaminpyridine. The (hypydc)2– ligands are coordinated to the metal center in a tridentate fashion as well as they act as bridging ligands and link two Zn(II) centers to each other. Interestingly in 1 a proton transfer ion pair of chelidamic acid and 3,4-diaminopyridine crystallized accompanied with neutral dinuclear complex of Zn(II). The coordination geometry in 1 for each Zn(II) atom is distorted pentagonal bipyramid. The crystal packing of compound 1 show 3D networks formed through H-bonds involving water molecules, NH groups of cations and carboxylate anions.
First-principles investigation of grain boundary structure effects on hydrogen solubility and segregation in tungsten
Published in Journal of Nuclear Science and Technology, 2021
Wenhao He, Xing Gao, Liangfu Zhou, Dongyan Yang, Zhiguang Wang, Juntao Liu, Zhiyi Liu, Yuhong Li
Similar to our previous investigations [30,31], eight symmetric tilt GBs, ∑3(110)[111], ∑3(111)[110], ∑5(310)[001], ∑5(210)[001], ∑9(114)[110], ∑11(332)[110], ∑17(410)[001], and ∑19(116)[110] were constructed by the CSL model [22], and the interstitial sites were identified with convex deltahedra in this study. There are five types of convex deltahedron, tetrahedron (TET), octahedron (OCT), pentagonal bipyramid (PBP), cap trigonal prism (CTP), and bitetrahedron (BTE) in these eight GBs studied here. The detailed schemes of constructing GBs and identifying interstitial sites in these GBs were elaborated in our previous studies [30,31].