Related Experiment Video
Updated: Apr 11, 2026
06:53
Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−
Published on: July 27, 2018
9.3K
Dissociative electron attachment to the gas-phase nucleobase hypoxanthine
M Michele Dawley1, Katrin Tanzer2, Ian Carmichael1
1Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA.
The Journal of Chemical Physics
|June 8, 2015
Summary
We studied electron attachment to hypoxanthine, a DNA/RNA base. The primary anion formed is (hypoxanthine - H), crucial for understanding biomolecular radiation damage.
Area of Science:
- Physical Chemistry
- Chemical Physics
- Biophysics
Background:
- Hypoxanthine is a purine base found in tRNA.
- Understanding its interaction with electrons is vital for biomolecular radiation damage studies.
Purpose of the Study:
- To investigate the dissociative electron attachment (DEA) process for gas-phase hypoxanthine.
- To identify anionic fragments and their formation mechanisms.
Main Methods:
- High-resolution measurements of DEA to hypoxanthine.
- Analysis of anion mass spectra and ion efficiency curves.
- Quantum chemical computations (B3LYP, U(MP2-aug-cc-pVDZ+)) for theoretical support.
Main Results:
- Dominant anion formation pathway observed at 1 eV: (hypoxanthine - H) anion (C5H3N4O(-)).
- Tentative assignment of the 1 eV resonance to a dipole-bound state of a specific hypoxanthine tautomer.
- Observation of seven other anions with broad resonances between 4-8 eV.
- Significant fragmentation observed during DEA to hypoxanthine.
Conclusions:
- The (hypoxanthine - H) anion is the primary product of electron attachment to hypoxanthine.
- DEA to hypoxanthine results in extensive fragmentation, relevant to radiation damage mechanisms in biological molecules.
Related Concept Videos
00:54Radical Formation: Homolysis
4.6K
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.
4.6K
01:23Hypoxia
2.6K
Hypoxia is a medical condition characterized by an inadequate oxygen supply to body tissues. It typically manifests as a bluish discoloration of the skin and mucosae, especially in fair-skinned individuals, when hemoglobin (Hb) saturation drops below 75%.
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
2.6K
00:47Radical Formation: Abstraction
4.5K
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...
4.5K
01:17Oxidation of Phenols to Quinones
5.4K
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
5.4K
01:43Electron Transport Chain: Complex III and IV
9.8K
During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...
9.8K
01:28Electron Transport Chains
118.0K
The final stage of cellular respiration is oxidative phosphorylation that consists of two steps: the electron transport chain and chemiosmosis. The electron transport chain is a set of proteins found in the inner mitochondrial membrane in eukaryotic cells. Its primary function is to establish a proton gradient that can be used during chemiosmosis to produce ATP and generate electron carriers, such as NAD+ and FAD, that are used in glycolysis and the citric acid cycle.
The ETC is comprised of...
The ETC is comprised of...
118.0K