Related Experiment Video
Updated: Apr 19, 2026
11:25
In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries
Published on: November 10, 2014
16.4K
Reductive lithium insertion into B-cation deficient niobium perovskite oxides.
Antonio Perejon1, Michael A Hayward
1Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK. michael.hayward@chem.ox.ac.uk.
Dalton Transactions (Cambridge, England : 2003)
|January 6, 2015
Summary
Lithium hydride (LiH) insertion into perovskite phases like Ba(5)Nb(4)O(15) creates new lithiated materials. Structural changes and electrical properties vary, with some becoming semiconductors and others insulators.
Area of Science:
- Solid-state chemistry
- Materials science
- Inorganic chemistry
Background:
- Cation-deficient perovskite phases, such as Ba(5)Nb(4)O(15), Ba(6)TiNb(4)O(18), and Ba(3)LaNb(3)O(12), exhibit unique structural characteristics.
- Understanding the reactivity of these complex oxides with reducing agents is crucial for developing new functional materials.
Purpose of the Study:
- To investigate the reaction between lithium hydride (LiH) and specific cation-deficient perovskite phases.
- To characterize the structural and electronic properties of the resulting lithiated products.
Main Methods:
- Reaction of LiH with Ba(5)Nb(4)O(15), Ba(6)TiNb(4)O(18), and Ba(3)LaNb(3)O(12) under reductive conditions.
- X-ray diffraction (XRD) analysis to determine crystal structures and stacking sequences.
- Transport measurements to evaluate electrical conductivity and semiconducting/insulating behavior.
Main Results:
- Reductive lithium insertion occurred, forming Ba(5)LiNb(4)O(15), Ba(6)LiTiNb(4)O(18), and Ba(3)LaLiNb(3)O(12).
- Lithium insertion into Ba(5)Nb(4)O(15) and Ba(6)TiNb(4)O(18) transformed stacking sequences to cubic and ordered B-cation sites into Li-Nb or Li-Nb/Ti.
- Lithium insertion into Ba(3)LaNb(3)O(12) resulted in cation disorder without significant structural change.
- Ba(5)LiNb(4)O(15) exhibited semiconducting behavior (variable range hopping), while Ba(6)LiTiNb(4)O(18) and Ba(3)LaLiNb(3)O(12) were insulating.
- Crystallographic charge ordering was suggested in Ba(6)LiTiNb(4)O(18).
Conclusions:
- The reaction pathway and resulting properties depend on the specific perovskite structure.
- Lithium insertion can significantly alter the structural order and electronic properties of cation-deficient perovskites.
- The study provides insights into the synthesis and characterization of novel lithiated perovskite materials.
More Related Videos
Related Concept Videos
00:55Nitriles to Amines: LiAlH4 Reduction
5.2K
Nitriles are reduced to amines in the presence of strong reducing agents like lithium aluminum hydride through a typical nucleophilic acyl substitution. The reaction requires two equivalents of the reducing agent. The reducing agent acts as a source of hydride ions.
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
5.2K
01:19Acid Halides to Alcohols: LiAlH4 Reduction
4.4K
Acid halides are reduced to alcohols in the presence of a strong reducing agent like lithium aluminum hydride.
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
4.4K
02:48Ionic Bonding and Electron Transfer
56.2K
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
56.2K
02:42Valence Bond Theory
11.9K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
11.9K
01:10α-Alkylation of Ketones via Enolate Ions
4.2K
Ketones with α protons are deprotonated by strong bases like lithium diisopropylamide (LDA) to form enolate ions. The anion is stabilized by resonance, and its hybrid structure exhibits negative charges on the carbonyl oxygen and the α carbon. This ambident nucleophile can attack an electrophile via two possible sites: the carbonyl oxygen, known as O-attack, or the α carbon, known as C-attack. The nucleophilic attack via the carbanionic site is preferred. This is due to the...
4.2K