Related Experiment Video
Updated: May 20, 2026
07:02
The Preparation and Properties of Thermo-reversibly Cross-linked Rubber Via Diels-Alder Chemistry
Published on: August 25, 2016
Dynamical (e,2e) studies of tetrahydrofurfuryl alcohol
S M Bellm1, J D Builth-Williams, D B Jones
1ARC Centre of Excellence for Antimatter-Matter Studies, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia. susan.bellm@flinders.edu.au
The Journal of Chemical Physics
|July 5, 2012
Summary
Electron scattering from DNA is crucial for understanding radiation damage. This study measured electron impact ionization of a DNA analogue, tetrahydrofurfuryl alcohol, revealing differences from theoretical models.
Area of Science:
- Atomic and Molecular Physics
- Chemical Physics
- Radiation Biology
Background:
- Electron scattering data are vital for modeling DNA radiation damage.
- Tetrahydrofurfuryl alcohol serves as a relevant analogue for the DNA's deoxyribose backbone.
- Understanding electron interactions with DNA components is key to biological radiation effects.
Purpose of the Study:
- To measure triply differential cross sections for electron impact ionization of tetrahydrofurfuryl alcohol.
- To investigate the electron scattering dynamics of the outer valence orbital.
- To compare experimental findings with theoretical predictions using the molecular 3-body distorted wave model.
Main Methods:
- Utilized the (e,2e) technique for electron scattering measurements.
- Employed coplanar asymmetric kinematics.
- Conducted experiments at an incident electron energy of 250 eV, ejected electron energy of 20 eV, and scattered electron angles of -5°, -10°, and -15°.
Main Results:
- Experimental cross section data for electron impact ionization were obtained.
- Comparison with theoretical calculations using the molecular 3-body distorted wave model was performed.
- Significant discrepancies were observed between experimental results and theoretical predictions.
Conclusions:
- The study provides valuable experimental cross section data for electron scattering from a DNA analogue.
- Observed differences highlight limitations in current theoretical models for describing electron-DNA interactions.
- Further refinement of theoretical models is needed for accurate radiation damage simulations.
Related Concept Videos
01:29UV–Vis Spectroscopy: Woodward–Fieser Rules
UV–Visible absorption spectra of conjugated dienes arise from the lowest energy π → π* transitions. The light-absorbing part of the molecule is called the chromophore, and the substituents directly attached to the chromophore are called auxochromes. A strong correlation exists between the absorption maxima, λmax, and the structure of a conjugated π system. The Woodward–Fieser rules predict the value of λmax for a given structure by adding the contributions...
02:35Acid-Catalyzed Dehydration of Alcohols to Alkenes
In a dehydration reaction, a hydroxyl group in an alcohol is eliminated along with the hydrogen from an adjacent carbon. Here, the products are an alkene and a molecule of water. Dehydration of alcohols is generally achieved by heating in the presence of an acid catalyst. While the dehydration of primary alcohols requires high temperatures and acid concentrations, secondary and tertiary alcohols can lose a water molecule under relatively mild conditions.
01:17Thermal Electrocyclic Reactions: Stereochemistry
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
02:29Ethers from Alcohols: Alcohol Dehydration and Williamson Ether Synthesis
Overview
Ethers can be prepared from organic compounds by various methods. Some of them are discussed below,
Preparation of Ethers by Alcohol Dehydration
In this method, in the presence of protic acids, alcohol dehydrates to produce alkenes and ethers under different conditions. For example, in the presence of sulphuric acid, dehydration of ethanol at 413 K yields ethoxyethane, whereas it yields ethene at 443 K.
Ethers can be prepared from organic compounds by various methods. Some of them are discussed below,
Preparation of Ethers by Alcohol Dehydration
In this method, in the presence of protic acids, alcohol dehydrates to produce alkenes and ethers under different conditions. For example, in the presence of sulphuric acid, dehydration of ethanol at 413 K yields ethoxyethane, whereas it yields ethene at 443 K.
02:45E2 Reaction: Kinetics and Mechanism
SN2 substitutions and E2 eliminations of alkyl halides proceed via a concerted pathway. While the nucleophile attacks the alpha carbon in SN2 reactions, it functions as a strong base and abstracts a beta hydrogen in the E2 mechanism. The rate-limiting transition state in E2 elimination reactions is characterized by partially broken carbon–hydrogen and carbon–halogen bonds and a partially formed pi bond between the alpha and beta carbons. The beta hydrogen and halide are eliminated...
![[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12417.jpg&w=3840&q=75)
01:16[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.