Control on Dimensions and Supramolecular Chirality of Self-Assemblies through Light and Metal Ions

2018 ◽  
Vol 140 (47) ◽  
pp. 16275-16283 ◽  
Author(s):  
Guofeng Liu ◽  
Jianhui Sheng ◽  
Wei Liang Teo ◽  
Guangbao Yang ◽  
Hongwei Wu ◽  
...  
Keyword(s):  
Metal Ions ◽  
Supramolecular Chirality

scholarly journals Metal-induced supramolecular chirality inversion of small self-assembled molecules in solution

2017 ◽  
Vol 53 (12) ◽  
pp. 1945-1948 ◽  
Author(s):  
Zoran Kokan ◽  
Berislav Perić ◽  
Mario Vazdar ◽  
Željko Marinić ◽  
Dražen Vikić-Topić ◽  
...  
Keyword(s):  
Metal Ions ◽  
Supramolecular Chirality ◽  
Self Assembled

The first example of supramolecular chirality inversion of small self-assembled ligands in solution by complexation to metal ions is presented.

scholarly journals Self-Assembly, Interfacial Nanostructure, and Supramolecular Chirality of the Langmuir-Blodgett Films of Some Schiff Base Derivatives without Alkyl Chain

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Tifeng Jiao ◽  
Ruirui Xing ◽  
Qingrui Zhang ◽  
Yaopeng Lv ◽  
Jingxin Zhou ◽  
...  
Keyword(s):  
Schiff Base ◽  
Metal Ions ◽  
Self Assembly ◽  
Alkyl Chain ◽  
Water Interface ◽  
Supramolecular Chirality ◽  
Air Water Interface ◽  
Langmuir Blodgett Films ◽  
Base Derivative

A special naphthyl-containing Schiff base derivative,N,N′-bis(2-hydroxy-1-naphthylidene)-1,2-phenylenediamine, was synthesized, and its coordination with various metal ions in situ at the air/water interface has been investigated. Although the ligand contains no alkyl chain, it can be spread on water surface. When metal ions existed in the subphase, an interfacial coordination between the ligand and different metal ions occurred in the spreading film, while different Nanostructures were fabricated in the monolayers. Interestingly to note that among various metal ions, only the in situ coordination-induced Cu(II)-complex film showed supramolecular chirality, although the multilayer films from the ligand or preformed complex are achiral. The chirality of the in situ Cu(II)-coordinated Langmuir film was developed due to the special distorted coordination reaction and the spatial limitation at the air/water interface. A possible organization mechanism at the air/water interface was suggested.

HREM Study of electron-induced surface radiation damage in ReO3

1991 ◽  
Vol 49 ◽  
pp. 636-637
Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Oxides ◽  
Electron Irradiation ◽  
Transition Metal Oxides ◽  
Carbon Film ◽  
Transition Metal Ions ◽  
Surface Radiation ◽  
Valence Transition ◽  
Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

ELNES of Iron Compounds

1990 ◽  
Vol 48 (2) ◽  
pp. 28-29
Author(s):  
Hiroki Kurata ◽  
Kazuhiro Nagai ◽  
Seiji Isoda ◽  
Takashi Kobayashi
Keyword(s):  
Energy Loss ◽  
Metal Ions ◽  
Energy Resolution ◽  
Transition Metal Oxides ◽  
Local Symmetry ◽  
Iron Compounds ◽  
Fine Structures ◽  
Electron Energy Loss ◽  
Fe Ions ◽  
Electron Energy Loss Spectra

Electron energy loss spectra of transition metal oxides, which show various fine structures in inner shell edges, have been extensively studied. These structures and their positions are related to the oxidation state of metal ions. In this sence an influence of anions coordinated with the metal ions is very interesting. In the present work, we have investigated the energy loss near-edge structures (ELNES) of some iron compounds, i.e. oxides, chlorides, fluorides and potassium cyanides. In these compounds, Fe ions (Fe2+ or Fe3+) are octahedrally surrounded by six ligand anions and this means that the local symmetry around each iron is almost isotropic.EELS spectra were obtained using a JEM-2000FX with a Gatan Model-666 PEELS. The energy resolution was about leV which was mainly due to the energy spread of LaB6 -filament. The threshole energies of each edges were measured using a voltage scan module which was calibrated by setting the Ni L3 peak in NiO to an energy value of 853 eV.

Sign in / Sign up

Export Citation Format

Share Document