Related Experiment Video
Updated: Jul 18, 2025
08:22
Nitrogen Compound Characterization in Fuels by Multidimensional Gas Chromatography
Published on: May 15, 2020
7.7K
Chemical evolution in nitrogen shocked beyond the molecular stability limit
Rebecca K Lindsey1,2, Sorin Bastea3, Yanjun Lyu2
1Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
The Journal of Chemical Physics
|August 25, 2023
Summary
Shock compression of nitrogen up to 100 GPa reveals that its dissociation is incomplete, forming short polymers. This finding revises classical models of nitrogen chemistry under extreme pressure.
Area of Science:
- Materials Science
- Physical Chemistry
- Computational Physics
Background:
- Understanding nitrogen behavior under extreme conditions is crucial for various scientific fields.
- Previous models often simplified shock compression chemistry.
Purpose of the Study:
- To investigate the evolution of nitrogen under shock compression using advanced simulation techniques.
- To develop and validate a machine-learned interatomic potential for nitrogen.
Main Methods:
- Molecular dynamics simulations with a machine-learned interatomic potential.
- Comparison with first-principles molecular dynamics and experimental data (Hugoniot curves).
Main Results:
- The machine-learned potential accurately reproduces structural, dynamic, and kinetic properties of shocked nitrogen.
- Evidence of short oligomer formation, indicating incomplete molecular dissociation.
- Discrepancies with experimental data suggest limitations in current models.
Conclusions:
- Classical models of shock-induced nitrogen dissociation require revision to include polymerization.
- The formation of oligomers is a significant factor in nitrogen chemistry under high pressure.
Related Concept Videos
01:20Overview of Nitrogen Metabolism
8.1K
Nitrogen is a very important element for life because it is a major constituent of proteins and nucleic acids. It is a macronutrient, and in nature, it is recycled from organic compounds and stored in the form of ammonia, ammonium ions, nitrate, nitrite, or nitrogen gas by many metabolic processes. Many of these metabolic processes are carried out only by prokaryotes.
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...
8.1K
01:49The Nitrogen Cycle
52.7K
Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of nitrogen on Earth is nitrogen gas, which cannot be used by most animals and plants. Thus, nitrogen gas must first be converted into a usable form by nitrogen-fixing bacteria before it can be cycled through other living organisms. The use of nitrogen-containing fertilizers and animal waste products in human agriculture has greatly influenced the...
52.7K
03:25Free Energy Changes for Nonstandard States
11.5K
The free energy change for a process taking place with reactants and products present under nonstandard conditions (pressures other than 1 bar; concentrations other than 1 M) is related to the standard free energy change according to this equation:
where R is the gas constant (8.314 J/K·mol), T is the absolute temperature in kelvin, and Q is the reaction quotient. This equation may be used to predict the spontaneity of a process under any given set of conditions.
Reaction Quotient...
where R is the gas constant (8.314 J/K·mol), T is the absolute temperature in kelvin, and Q is the reaction quotient. This equation may be used to predict the spontaneity of a process under any given set of conditions.
Reaction Quotient...
11.5K
00:55Mass Spectrometry: Amine Fragmentation
1.7K
Amines can be identified using mass spectroscopy based on their characteristic fragmentation patterns. The molecular ions of amines undergo fragmentation via ⍺-cleavage. The ⍺-cleavage of the carbon-carbon bonds in amines generates an alkyl radical and resonance-stabilized nitrogen-containing cation.
In amines, the number of nitrogen atoms affects the mass of the molecular ion, which is described by the nitrogen rule of mass spectrometry. This rule states that a compound containing...
In amines, the number of nitrogen atoms affects the mass of the molecular ion, which is described by the nitrogen rule of mass spectrometry. This rule states that a compound containing...
1.7K
01:22Inorganic Nitrogen Assimilation
44
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme...
44
01:19Mass Spectrometry of Amines
4.2K
In mass spectroscopy, amines undergo fragmentation to give parent ions with odd molecule weights. This observed mass spectrum follows the nitrogen rule: a molecule with an odd number of nitrogen atoms produces a parent ion with an odd molecular weight. The remaining fragments have an even mass.
Amines undergo fragmentation through α cleavage, producing nitrogen-containing cations—iminium ions—and alkyl radicals. Mass spectra of aromatic and cyclic aliphatic amines exhibit...
Amines undergo fragmentation through α cleavage, producing nitrogen-containing cations—iminium ions—and alkyl radicals. Mass spectra of aromatic and cyclic aliphatic amines exhibit...
4.2K