Topic
Amphoterism
About: Amphoterism is a research topic. Over the lifetime, 26 publications have been published within this topic receiving 351 citations. The topic is also known as: amphoteric & amphotericity.
Papers
TL;DR: The amphoteric nature of ZnO is used to produce the material from strongly alkaline solution, which grows with a sea urchin-like nanostructure, whereas the electrodeposited films have a columnar structure.
Abstract: The amphoteric nature of ZnO is used to produce the material from strongly alkaline solution. The solution pH is lowered globally to produce ZnO powder, and it is lowered locally at a Au(111) surface to produce epitaxial films. ZnO powder is precipitated from a solution of 10 mM Zn(II) in 0.25 M NaOH by simply adding 1 M HNO3 to the solution. For the film electrodeposition, the local pH at the electrode surface is decreased by electrochemically oxidizing the ascorbate dianion. The chemically precipitated ZnO powder grows with a sea urchin-like nanostructure, whereas the electrodeposited films have a columnar structure. ZnO electrodeposited onto a Au(111) single crystal has a ZnO(0001)[1011]//Au(111)[110] orientation relationship.
79 citations
TL;DR: In this article, a search was undertaken for acids belonging to the hydrogen fluoride system, and it was found that due to the extremely acid nature of the solvent, the substances capable of acting as acids in it were indeed limited in number.
59 citations
TL;DR: The reactivity of Mn2O3 and late rare-earth sesquioxides in alkaline aqueous solution affords a high-yield formation of rare earth manganites, LnMnO3 (Ln = HoLu and Y) as discussed by the authors.
Abstract: The reactivity of Mn2O3 and late rare-earth sesquioxides in alkaline aqueous solution affords a high-yield formation of rare-earth manganites, LnMnO3 (Ln = Ho–Lu and Y). The yield of the products depends significantly on the pH, which determines the solubility of the manganese cation, and reaction temperature, which regulates the decomposition of the insoluble rare-earth trihydroxide, Ln(OH)3, to the more reactive oxide hydroxide, LnO(OH). Plate- and needle-like LnMnO3 crystallites of a few micrometers in size have been prepared at reaction temperatures where the rare-earth oxide hydroxide is thermodynamically stable, whereas at lower temperatures the insoluble rare-earth trihydroxide persists and no reaction is observed.
36 citations
TL;DR: This study delineates how structural constraints can invert thermodynamics for seemingly simple addition reactions and invert common trends in bond energies.
Abstract: Most p-block metal amides irreversibly react with metal alkoxides when subjected to alcohols, making reversible transformations with OH-substrates a challenging task. Herein, we describe how the combination of a Lewis acidic square-planar-coordinated aluminum(III) center with metal–ligand cooperativity leverages unconventional reactivity toward protic substrates. Calix[4]pyrrolato aluminate performs OH-bond activation of primary, secondary, and tertiary aliphatic and aromatic alcohols, which can be fully reversed under reduced pressure. The products exhibit a new form of metal–ligand cooperative amphoterism and undergo counterintuitive substitution reactions of a polar covalent Al–O bond by a dative Al–N bond. A comprehensive mechanistic picture of all processes is buttressed by isolation of intermediates, spectroscopy, and computation. This study delineates how structural constraints can invert thermodynamics for seemingly simple addition reactions and invert common trends in bond energies.
25 citations
15 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 2 |
| 2016 | 1 |
| 2015 | 1 |
| 2014 | 1 |
| 2013 | 1 |
| 2010 | 2 |