Related Experiment Video
Updated: Jul 11, 2025
08:00
Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain
Published on: March 27, 2018
11.1K
Low-temperature modification of Ba(BF4)2(H2O)3
Evgeny Goreshnik1, Andrii Vakulka2, Gašper Tavčar1
1Department of Inorganic Chemistry and Technology, Jožef Stefan Institute, Jamova 39 1000 Ljubljana, Slovenia.
Iucrdata
|November 8, 2023
Summary
The crystal structure of barium bis(tetra-fluorido-borate) trihydrate was determined at low temperatures. This study reveals a new monoclinic crystal structure for Ba(BF4)2(H2O)3, distinct from its room-temperature orthorhombic form.
Area of Science:
- Inorganic Chemistry
- Crystallography
- Materials Science
Background:
- Barium bis(tetra-fluorido-borate) trihydrate (Ba(BF4)2(H2O)3) exhibits different crystalline forms depending on temperature.
- Understanding the structural transitions is crucial for predicting material properties and applications.
Purpose of the Study:
- To determine the crystal structure of the low-temperature modification of Ba(BF4)2(H2O)3.
- To elucidate the structural differences between the low-temperature and room-temperature phases.
Main Methods:
- Single-crystal X-ray diffraction at 150 K.
- Analysis of crystallographic data, including space group, unit cell parameters, and atomic positions.
- Identification of hydrogen bonding networks within the crystal structure.
Main Results:
- The low-temperature phase of Ba(BF4)2(H2O)3 crystallizes in the monoclinic space group P21.
- Unit cell parameters for the low-temperature phase: a = 7.0550(4) Å, b = 7.1706(3) Å, c = 9.4182(6) Å, β = 109.295(7)°, V = 449.68(5) ų, Z = 2.
- The structure features O-H⋯F and O-H⋯O hydrogen bonds, with one water molecule exhibiting disorder.
Conclusions:
- The low-temperature phase of Ba(BF4)2(H2O)3 presents a distinct monoclinic structure compared to the room-temperature orthorhombic form.
- Hydrogen bonding plays a significant role in stabilizing the low-temperature crystal structure.
- The observed structural transition highlights the temperature-dependent polymorphism of barium bis(tetra-fluorido-borate) trihydrate.
Related Concept Videos
03:08Hydroboration-Oxidation of Alkenes
8.3K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
8.3K
01:26Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
1.8K
Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...
1.8K
01:19Acid Halides to Alcohols: LiAlH4 Reduction
2.9K
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...
2.9K
02:15Preparation of Alcohols via Addition Reactions
6.3K
Overview
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
6.3K
02:23Alcohols from Carbonyl Compounds: Reduction
10.4K
Reduction is a simple strategy to convert a carbonyl group to a hydroxyl group. The three major pathways to reduce carbonyls to alcohols are catalytic hydrogenation, hydride reduction, and borane reduction.
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...
10.4K