Related Experiment Video
Updated: Jun 4, 2026
06:32
A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions
Published on: August 17, 2016
Computational study of H2 generation from BH3 and BH3 - with HO˙ radical
Trinh Le Huyen1,2, Pham Cam Nam1,2
1Faculty of Chemical Engineering, University of Science and Technology, The University of Danang Danang 550000 Vietnam pcnam@dut.udn.vn.
RSC Advances
|June 3, 2026
Summary
Hydrogen generation from boron hydrides, crucial for clean energy, is explored. Anionic boron hydride reactions with hydroxyl radicals show enhanced hydrogen formation via stabilized intermediates and tunneling.
Area of Science:
- Chemical kinetics
- Computational chemistry
- Energy science
Background:
- Hydrogen formation via boron hydrides is relevant to clean energy and radical chemistry.
- Understanding reaction mechanisms is key for optimizing hydrogen generation.
Purpose of the Study:
- Investigate hydrogen generation mechanisms from neutral and anionic boron hydrides reacting with hydroxyl radicals.
- Determine the kinetics and influencing factors in both gas and aqueous phases.
Main Methods:
- Density functional theory (DFT) at M06-2X/6-311++G(d,p) level.
- Transition State Theory (TST) with Wigner tunneling corrections.
- Computational analysis in gas and aqueous environments.
Main Results:
- Identified reaction pathways with stabilized pre-reactive intermediates and hydrogen transfer.
- Anionic systems showed stronger donor-acceptor interactions, facilitating H-H bond formation.
- Observed temperature dependence and significant tunneling effects, with negative temperature dependence in the gas phase.
Conclusions:
- Boron hydride reactions with hydroxyl radicals offer viable hydrogen formation pathways.
- Reactivity is controlled by intermediate stabilization, tunneling, pH, and diffusion.
- Findings provide insights into hydrogen generation mechanisms for energy applications.
Related Concept Videos
02:36Regioselectivity and Stereochemistry of Hydroboration
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
00:47Radical Formation: Abstraction
The electron of an atom can be abstracted from a compound by a relatively unstable radical to generate a new radical of relatively greater stability. For example, an initiator which forms radicals by homolysis can abstract a suitable species like a hydrogen atom or a halogen atom from a compound to generate a new radical. This ability of radicals to propagate by abstraction is a crucial feature of radical chain reactions.
Even though homolysis produces radicals, it is different from radical...
Even though homolysis produces radicals, it is different from radical...
01:26Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
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 reactions,...
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 reactions,...
01:17Electrophilic 1,2- and 1,4-Addition of HX to 1,3-Butadiene
The electrophilic addition of hydrogen halides such as HBr to alkenes and nonconjugated dienes gives a single product as per Markovnikov’s rule.
00:54Radical Formation: Homolysis
A bond is formed between two atoms by sharing two electrons. When this bond is broken by supplying sufficient energy, either two electrons can be taken up by one atom forming ions by the cleavage called heterolysis, or the two electrons are shared by two atoms, with one each creating radicals by the cleavage called homolysis.
03:24Hybridization of Atomic Orbitals I
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...