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

2.4K
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
2.4K
Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

3.2K
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.
3.2K
Pericyclic Reactions: Introduction01:17

Pericyclic Reactions: Introduction

10.9K
Pericyclic reactions are organic reactions that occur via a concerted mechanism without generating any intermediates. The reactions proceed through the movement of electrons in a closed loop to form a cyclic transition state, where rearrangement of the σ and π bonds yields specific products.
Pericyclic reactions can be classified into three categories: electrocyclic reactions, cycloaddition reactions, and sigmatropic rearrangements. Electrocyclic reactions and sigmatropic...
10.9K
Thermal Electrocyclic Reactions: Stereochemistry01:17

Thermal Electrocyclic Reactions: Stereochemistry

2.7K
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.
2.7K
Electron Transport Chain: Complex III and IV01:43

Electron Transport Chain: Complex III and IV

9.7K
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...
9.7K
Cycloaddition Reactions: Overview01:16

Cycloaddition Reactions: Overview

3.7K
Cycloadditions are one of the most valuable and effective synthesis routes to form cyclic compounds. These are concerted pericyclic reactions between two unsaturated compounds resulting in a cyclic product with two new σ bonds formed at the expense of π bonds. The [4 + 2] cycloaddition, known as the Diels–Alder reaction, is the most common. The other example is a [2 + 2] cycloaddition.
3.7K

You might also read

Related Articles

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

Sort by
Same author

A Network Pharmacology Study on the Active Ingredients and Potential Targets of <i>Tripterygium wilfordii</i> Hook for Treatment of Rheumatoid Arthritis.

Evidence-based complementary and alternative medicine : eCAM·2019
Same author

A PAH-degrading bacterial community enriched with contaminated agricultural soil and its utility for microbial bioremediation.

Environmental pollution (Barking, Essex : 1987)·2019
Same author

Size-Dependent Relaxation Processes of Photoexcited [ n]Cycloparaphenylenes ( n = 5-12): Significant Contribution of Internal Conversion in Smaller Rings.

The journal of physical chemistry. A·2019
Same author

NfiR, a New Regulatory Noncoding RNA (ncRNA), Is Required in Concert with the NfiS ncRNA for Optimal Expression of Nitrogenase Genes in Pseudomonas stutzeri A1501.

Applied and environmental microbiology·2019
Same author

A novel homolateral and dicationic AIEgen for the sensitive detection of casein.

The Analyst·2019
Same author

Terahertz Oscilloscope for Recording Time Information of Ultrashort Electron Beams.

Physical review letters·2019

Related Experiment Video

Updated: Mar 26, 2026

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes
09:17

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes

Published on: January 30, 2015

12.5K

Multistep Electron Transfer Systems Containing [2.2]- or [3.3]Paracyclophane.

Mamoru Fujitsuka1, Takaaki Miyazaki2, Chao Lu1

  • 1The Institute of Scientific and Industrial Research (SANKEN), Osaka University , Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan.

The Journal of Physical Chemistry. A
|February 9, 2016
PubMed
Summary

Strain in paracyclophanes (PCPs) enhances electron transfer (ET) rates. Using [3.3]PCP over [2.2]PCP in dyads and triads improved charge separation due to lower oxidation potentials and reorganization energy.

More Related Videos

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
07:12

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

6.8K
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

9.3K

Related Experiment Videos

Last Updated: Mar 26, 2026

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes
09:17

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes

Published on: January 30, 2015

12.5K
Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
07:12

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

6.8K
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

9.3K

Area of Science:

  • Supramolecular Chemistry
  • Photochemistry
  • Electron Transfer Systems

Background:

  • Paracyclophanes (PCPs) are utilized as spacers in electron transfer (ET) systems due to their unique transannular interactions.
  • Investigating multistep ET processes requires understanding the role of donor molecules like PCPs.

Purpose of the Study:

  • To investigate electron transfer (ET) processes in dyads and triads incorporating [2.2]paracyclophane ([2.2]PCP) or [3.3]paracyclophane ([3.3]PCP) as donors.
  • To evaluate the impact of different PCP structures on charge separation (CS) and charge shift (CS) dynamics in multistep ET.

Main Methods:

  • Synthesis and characterization of dyad and triad molecules containing PCPs, 1,8-naphthalimide (NI), and carbazole.
  • Photophysical studies, including excitation and analysis of charge separation and charge shift processes upon photoexcitation.

Main Results:

  • Dyads of PCP and NI exhibited charge separation (CS) upon NI excitation.
  • [3.3]PCP containing triads demonstrated charge shift following initial CS, confirming multistep ET.
  • Employing [3.3]PCP instead of [2.2]PCP significantly enhanced the initial CS rate.

Conclusions:

  • The enhanced CS rate with [3.3]PCP is attributed to its lower oxidation potentials and smaller reorganization energy.
  • The strained structure of PCPs plays a crucial role in their electronic properties and ET efficiency.
  • This study highlights the importance of molecular strain in designing efficient electron transfer systems.