A New Route for The Synthesis of Reduced Transition Metal Oxides Using Borohydrides

1994 ◽  
Vol 346 ◽  
Author(s):  
A. Manthiram ◽  
Y. T. Zhu ◽  
A. Dananjay
Keyword(s):  
Low Temperature ◽  
Transition Metal ◽  
Alkali Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Binary Oxides ◽  
Oxide Bronzes

ABSTRACTReduction of aqueous solutions of tungstates, molybdates or vanadates by aqueous alkali metal borohydrides at ambient‐temperature results in a formation of dark colored gel. The gel is amorphous to X‐ray diffraction and crystallizes sharply at around 300‐500 °C to yield reduced transition metal oxides such as the oxide bronzes, NaxMyOz, or the binary oxides, MO2 (M = V, Mo or W). The nature and composition of the products formed are strongly influenced by the reaction conditions such as the reaction pH as well as the concentration and amount of the reagents. Experimental procedures to obtain the different phases are presented. This novel low‐temperature approach has a potential to access new metastable phases.

Low Temperature Synthesis of Lamellar Transition Metal Oxides Containing Surfactant Ions

1996 ◽  
Vol 457 ◽  
Author(s):  
Gerald G. Janauer ◽  
Rongji Chen ◽  
Arthur D. Dobley ◽  
Peter Y. Zavalij ◽  
M. Stanley Whittingham
Keyword(s):  
Low Temperature ◽  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Layered Compounds ◽  
Vanadium Compound ◽  
Low Temperature Synthesis ◽  
X Ray ◽  
Mechanisms Of Formation

ABSTRACTRecently there has been much interest in reacting vanadium oxides hydrothermally with cationic surfactants to form novel layered compounds. A series of new transition metal oxides, however, has also been formed at or near room temperature in open containers. Synthesis, characterization, and proposed mechanisms of formation are the focus of this work. Low temperature reactions of vanadium pentoxide and ammonium (DTA) transition metal oxides with long chain amine surfactants, such as dodecyltrimethylammonium bromide yielded interesting new products many of which are layered phases. DTA4H2V10O28•8H2O, a layered highly crystalline phase, is the first such phase for which a single crystal X-ray structure has been determined. The unit cell for this material was found to be triclinic with space group P 1 and dimensions a=9.895(1)Å, b=11.596(1)Å, c=21.924(1)Å, α=95.153(2)°, β=93.778(1)°, and γ= 101.360(1)°. Additionally, we synthesized a dichromate phase and a manganese chloride layered phase, with interlayer spacings of 26.8Å, and 28.7Å respectively. The structure, composition, and synthesis of the vanadium compound are described, as well as the synthesis and preliminary characterization of the new chromium and manganese materials.

Orbital moment determination of simple transition metal oxides using magnetic X-ray diffraction

2001 ◽  
Vol 62 (12) ◽  
pp. 2173-2180 ◽  
Author(s):  
W. Neubeck ◽  
C. Vettier ◽  
F. de Bergevin ◽  
F. Yakhou ◽  
D. Mannix ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
X Ray Diffraction ◽  
Orbital Moment ◽  
X Ray

Synthesis of Transition-Metal-Oxides Meso-Structured Thin Films

1998 ◽  
Vol 549 ◽  
Author(s):  
H.S. Zhou ◽  
I. Honma
Keyword(s):  
Thin Films ◽  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Self Assembly ◽  
Magnetic Interactions ◽  
X Ray Diffraction ◽  
Structured Materials ◽  
Coating Method ◽  
Diffraction Patterns

AbstractHighly ordered self-assembly organized silica meso-structured architectures have attracted increasing attention because these materials provide a rich source for scientific research and technological applications. This approach to meso-structured materials has been extended to non-silica oxides, especially transition-metal-oxides which might promise applications involving electron transfer or magnetic interactions. We report the syntheses of transition-metal-oxides meso-structured thin films (MSTF), such as TiO2, V2O5, Fe2O3 and Nb2O5, using a surfactant templating processing with spin coating method. X-ray diffraction patterns of the films showed that the films generally oriented in a lamellar structure. The phase transferring in V205 MSTF was also investigated.

scholarly journals Influence of shallow core-level hybridization on the electronic structure of post-transition-metal oxides studied using soft X-ray emission and absorption

2003 ◽  
Vol 68 (16) ◽  
Author(s):  
Cormac McGuinness ◽  
Cristian B. Stagarescu ◽  
Philip J. Ryan ◽  
James E. Downes ◽  
Dongfeng Fu ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Core Level ◽  
X Ray

The prediction of metal-to-metal bonding in transition metal binary and related compounds

1964 ◽  
Vol 17 (11) ◽  
pp. 1191 ◽  
Author(s):  
JC Sheldon
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Valence State ◽  
Oxidation States ◽  
Metal Bonding ◽  
Binary Oxides ◽  
Lower Oxidation ◽  
D Orbitals ◽  
Related Compounds

The evidence for, and the factors determining, the formation of metal-to-metal (m-m) bonds in transition metal oxides, sulphides, halides, and related complexes are discussed. It is proposed that when metals of high preferred valence state are constrained to low formal oxidation states, m-m bonds will form to allow the metal to exercise a higher valency. It is assumed that (n-l)d orbitals are used for such bonds and predictions of the feasibility of m-m bonding are possible by the comparison of the size of such orbitals with the expected inter-metal distances in polymeric metal oxides and halides. It is concluded that binary oxides and halides (excepting fluorides) of the lower oxidation states of Zr, Hf, Nb, Ta, Mo, W, and Re and of a few neighbouring elements will display m-m bonds.

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