Effects of metal ions on the equilibria of methanol and methoxide ion addition to benzaldehydes. Effect of a poly(oxyethylene) side arm

1991 ◽  
Vol 56 (22) ◽  
pp. 6331-6336 ◽  
Author(s):  
Giancarlo Doddi ◽  
Gianfranco Ercolani ◽  
Paolo Mencarelli ◽  
Carlo Scalamandre
Keyword(s):  
Metal Ions ◽  
Methoxide Ion

scholarly journals Catalysis by alkali and alkaline-earth metal ions in nucleophilic attack of methoxide ion on crown ethers bearing an intra-annular acetoxy group

Tetrahedron ◽  
1989 ◽  
Vol 45 (16) ◽  
pp. 5293-5304 ◽  
Author(s):  
Roberta Cacciapaglia ◽  
Silvia Lucente ◽  
Luigi Mandolini ◽  
Arie R. van Doorn ◽  
David N. Reinhoudt ◽  
...  
Keyword(s):  
Metal Ions ◽  
Crown Ethers ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Acetoxy Group ◽  
Nucleophilic Attack ◽  
Alkaline Earth Metal ◽  
Alkaline Earth Metal Ions ◽  
Methoxide Ion

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.

Metal Ions in Life Sciences

2011 ◽  
Keyword(s):  
Metal Ions ◽  
Life Sciences

Solvent Exchange on Metal Ions

2003 ◽  
Keyword(s):  
Metal Ions ◽  
Solvent Exchange

Direct detection of heavy metal ions using liquid crystals

2020 ◽  
Author(s):  
Sulayman Oladepo
Keyword(s):  
Heavy Metal ◽  
Liquid Crystals ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Direct Detection

Interaction of divalent metal ions with the NADP+-malic enzyme from maize leaves

1991 ◽  
Vol 81 (4) ◽  
pp. 462-466 ◽  
Author(s):  
Maria Fabiana Drincovich ◽  
Alberto A. Iglesias ◽  
Carlos S. Andreo
Keyword(s):  
Metal Ions ◽  
Malic Enzyme ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Maize Leaves
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