Related Experiment Video
Updated: Jun 3, 2026
10:52
Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
Ab initio molecular dynamics study of H2 formation inside POSS compounds
Takako Kudo1, Tetsuya Taketsugu, Mark S Gordon
1Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu 376-8515, Japan.
The Journal of Physical Chemistry. A
|March 15, 2011
Summary
Researchers studied hydrogen molecule formation within polyhedral oligomeric silsesquioxanes (POSS) cages. They observed hydrogen molecule formation through stepwise atom incorporation and collisions inside POSS structures.
Area of Science:
- Computational Chemistry
- Materials Science
- Nanotechnology
Background:
- Polyhedral oligomeric silsesquioxanes (POSS) are nanoscale cage compounds with potential applications in materials science.
- Understanding guest molecule encapsulation and reactions within POSS cavities is crucial for designing new materials and processes.
Purpose of the Study:
- To investigate the mechanism and dynamics of hydrogen molecule formation within two types of POSS cages: T(8) and T(12).
- To explore the stepwise incorporation of hydrogen atoms and their subsequent reaction to form H(2) inside POSS.
Main Methods:
- Ab initio molecular orbital and ab initio molecular dynamics (AIMD) methods were employed.
- CASSCF level of theory was used for AIMD simulations, focusing on the active space of colliding hydrogen atoms.
- Simulations involved inserting a second hydrogen atom into a POSS cage already containing one hydrogen atom (H + H@T(n) → H(2)@T(n)).
Main Results:
- Gradual formation of a hydrogen molecule (H(2)) was observed within the POSS cages after repeated collisions of hydrogen atoms.
- The dynamics of hydrogen encapsulation and subsequent molecule formation were analyzed for both T(8) and T(12) POSS structures.
- The influence of an argon atom within the T(12) POSS cage on hydrogen molecule formation was also examined.
Conclusions:
- The study elucidates a viable pathway for hydrogen molecule formation within POSS nanostructures via stepwise atom incorporation and intra-cage reactions.
- These findings contribute to the understanding of host-guest chemistry in POSS systems and could inform future applications in hydrogen storage or catalysis.
Related Concept Videos
03:51Molecular Orbital Theory II
Molecular Orbital Energy Diagrams
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.
01:24π Molecular Orbitals of 1,3-Butadiene
Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
02:40MO Theory and Covalent Bonding
The molecular orbital theory describes the distribution of electrons in molecules in a manner similar to the distribution of electrons in atomic orbitals. The region of space in which a valence electron in a molecule is likely to be found is called a molecular orbital. Mathematically, the linear combination of atomic orbitals (LCAO) generates molecular orbitals. Combinations of in-phase atomic orbital wave functions result in regions with a high probability of electron density, while...
02:37VSEPR Theory
Valence shell electron-pair repulsion theory (VSEPR theory) enables us to predict the molecular structure around a central atom from an examination of the number of bonds and lone electron pairs in its Lewis structure. The VSEPR model assumes that electron pairs in the valence shell of a central atom will adopt an arrangement that minimizes repulsions between these electron pairs by maximizing the distance between them. The electrons in the valence shell of a central atom form either bonding...
01:01Introduction to Chemical Bonds
Chemical Bonds
The electrons of the outermost energy level determine the energetic stability of the atom and its tendency to form chemical bonds with other atoms. The innermost electron shell has a maximum capacity of two electrons, but the next two electron shells can each have a maximum of eight electrons. This is known as the octet rule, which states that, with the exception of the innermost shell, atoms are most stable energetically when they have eight electrons in their valence shell, the...
The electrons of the outermost energy level determine the energetic stability of the atom and its tendency to form chemical bonds with other atoms. The innermost electron shell has a maximum capacity of two electrons, but the next two electron shells can each have a maximum of eight electrons. This is known as the octet rule, which states that, with the exception of the innermost shell, atoms are most stable energetically when they have eight electrons in their valence shell, the...