Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
Cationic Chain-Growth Polymerization: Mechanism00:57

Cationic Chain-Growth Polymerization: Mechanism

The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...
Deactivation Processes: Jablonski Diagram01:25

Deactivation Processes: Jablonski Diagram

Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...
Step-Growth Polymerization: Overview01:03

Step-Growth Polymerization: Overview

Step-growth or condensation polymerization is a stepwise reaction of bi or multifunctional monomers to form long-chain polymers. As all the monomers are reactive, most of the monomers are consumed at the early stages of the reaction to form small chains of reactive oligomers, which then combine to form long polymer chains in the late stages. Hence, the reaction has to proceed for a long time to achieve high molecular weight polymers.
Many natural and synthetic polymers are produced by...
Electron Behavior00:54

Electron Behavior

Overview
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Experimental and Multiscale Modeling Insights for Radiation-Driven Neptunium Redox Processes at Elevated Temperatures.

The journal of physical chemistry. A·2026
Same author

Podium Abstracts Presented at the 2025 Annual Meeting of the Arthroscopy Association of North America.

Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association·2026
Same author

Emulsion-engineered polylactide-based polyurethane/MXene films for high-performance flexible and biointegrated wearable sensors.

iScience·2026
Same author

Influence of Nd(II) and Nd(III) Ions on the Speciation and Kinetic Dynamics of Radiolytic Transients in Molten LiCl-KCl Eutectic Salt Mixtures.

Inorganic chemistry·2026
Same author

Bucket-Handle Meniscus Tears: Epidemiology, Diagnosis, Management, and Outcomes.

JBJS reviews·2025
Same author

Impacts of molecular architecture on the radiation-induced degradation and reaction kinetics of hydrophobic diglycolamides with the solvated electron and the dodecane radical cation.

Physical chemistry chemical physics : PCCP·2025
Same journal

Kinetic and Mechanistic Insights into H-Abstraction and Subsequent Isomerization and Decomposition of Monoglyme and Key Combustion Intermediates.

The journal of physical chemistry. A·2026
Same journal

First-Principles Analysis of Protonation-Induced Electronic Effects in Tetrakis(<i>p</i>-aminophenyl)porphyrin (TAPP).

The journal of physical chemistry. A·2026
Same journal

Exploring the Reactivity of the CH Radical toward Nitrous Oxide in the Context of the Interstellar Medium.

The journal of physical chemistry. A·2026
Same journal

Infrared Photodissociation Spectroscopy of Benzene-V<sup>+</sup>(CO)<sub>n</sub> "Piano Stool" Cations.

The journal of physical chemistry. A·2026
Same journal

Correction to "Solvent-Dependent Ultrafast Photochemical Dynamics of <i>N</i>-Methyl Oxindole Overcrowded Alkene Molecular Motors".

The journal of physical chemistry. A·2026
Same journal

Accelerating the Discovery of Superhalogens via Physics-Informed Graph Neural Networks.

The journal of physical chemistry. A·2026
See all related articles

Related Experiment Video

Updated: May 29, 2026

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
10:35

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Published on: May 29, 2018

Sudden, "step" electron capture by conjugated polymers.

Andrew R Cook1, Paiboon Sreearunothai, Sadayuki Asaoka

  • 1Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793-5000, USA. acook@bnl.gov

The Journal of Physical Chemistry. A
|September 8, 2011
PubMed
Summary
This summary is machine-generated.

Conjugated polyfluorene polymers efficiently capture electrons generated by pulse radiolysis. This fast electron capture in polyfluorenes enhances radical anion yield for picosecond timescale chemistry studies.

More Related Videos

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds
11:44

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Published on: October 18, 2018

Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering
06:16

Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering

Published on: December 21, 2017

Related Experiment Videos

Last Updated: May 29, 2026

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
10:35

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Published on: May 29, 2018

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds
11:44

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Published on: October 18, 2018

Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering
06:16

Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering

Published on: December 21, 2017

Area of Science:

  • Physical Chemistry
  • Polymer Science
  • Radiation Chemistry

Background:

  • Understanding electron capture mechanisms is crucial for radiation chemistry.
  • Conjugated polymers offer unique electronic properties for studying charge carrier dynamics.
  • Previous studies on biphenyl in tetrahydrofuran (THF) established a benchmark for presolvated electron capture.

Purpose of the Study:

  • To investigate the time-resolved "step" capture of electrons by conjugated polyfluorene polymers.
  • To determine the efficiency of electron capture in polyfluorenes of varying lengths and concentrations.
  • To explore mechanisms responsible for fast electron capture in these polymer systems.

Main Methods:

  • Utilized 7-10 picosecond (ps) electron pulses for pulse radiolysis experiments.
  • Studied a series of conjugated polyfluorene polymers with varying lengths and concentrations in THF.
  • Analyzed electron capture kinetics and efficiency as a function of polymer concentration and molecular structure.

Main Results:

  • Observed significant time-resolution-limited "step" capture of electrons by polyfluorenes.
  • At high concentrations (∼48 mM), approximately 30% of radiolytically generated electrons were captured.
  • Capture efficiency per repeat unit was constant, and significantly higher per polymer molecule compared to biphenyl.

Conclusions:

  • Both quasi-free and localized presolvated electron capture mechanisms can explain the observed fast capture kinetics.
  • The high electron capture efficiency in polyfluorenes facilitates the study of subsequent chemistry on the picosecond timescale.
  • These findings open avenues for utilizing polyfluorenes in advanced materials for radiation-induced processes.