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

1.8K
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
1.8K
Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

2.3K
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.
2.3K
The Z-Scheme of Electron Transport in Photosynthesis01:34

The Z-Scheme of Electron Transport in Photosynthesis

10.1K
The light reactions of photosynthesis assume a linear flow of electrons from water to NADP+. During this process, light energy drives the splitting of water molecules to produce oxygen. However, oxidation of water molecules is a thermodynamically unfavorable reaction and requires a strong oxidizing agent. This is accomplished by the first product of light reactions: oxidized P680 (or P680+), the most powerful oxidizing agent known in biology. The oxidized P680 that acquires an electron from the...
10.1K
Photosystem I01:27

Photosystem I

62.1K
Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
62.1K
Redox Reactions01:24

Redox Reactions

55.6K
Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
55.6K
Oxidation and Reduction of Organic Molecules01:19

Oxidation and Reduction of Organic Molecules

6.5K
Energy production within a cell involves many coordinated chemical pathways. Most of these pathways are combinations of oxidation and reduction reactions, which occur at the same time. An oxidation reaction strips an electron from an atom in a compound, and the addition of this electron to another compound is a reduction reaction. Because oxidation and reduction usually occur together, these pairs of reactions are called redox reactions.
The removal of an electron from a molecule, results in a...
6.5K

You might also read

Related Articles

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

Sort by
Same author

A Synthetic Iron Model of Carbon-Sulfur Bond Activation by the Nitrogenase-Family Enzyme Methylthio-Alkane Reductase.

Journal of the American Chemical Society·2026
Same author

Iron Complexes Supported by a Dual Dearomatized PNPN Ligand.

Inorganic chemistry·2026
Same author

Photodriven Sm-Catalyzed Asymmetric Ketyl-Olefin Coupling.

Journal of the American Chemical Society·2026
Same author

Remote Positioning of Cations Tunes Catalytic Fe-Mediated Nitrogen Fixation Selectivity for Hydrazine Instead of Ammonia in Protic Media.

Angewandte Chemie (International ed. in English)·2026
Same author

Tunable Multisite Proton-Coupled Electron Transfer Mediators: Distinct Pathways for Substrate Reduction Versus Competing Hydrogen Evolution.

Journal of the American Chemical Society·2026
Same author

Cation Competition Experiments during Electrochemical CO<sub>2</sub> Reduction As a Probe of the Film-Modified Copper Microenvironment.

Journal of the American Chemical Society·2025
Same journal

A Ni-Mediated Cross-Coupling Approach to Deuterated <sup>18</sup>F- Fluoromethylated (Hetero)arenes.

Journal of the American Chemical Society·2026
Same journal

Efficient Light-Driven CO<sub>2</sub> Capture and Reversible Release Enabled by Metastable Photoacid-Decorated Metal-Organic Frameworks.

Journal of the American Chemical Society·2026
Same journal

In Situ Raman Spectroscopy Reveals the Dynamic Evolution and Ethanol Dependence of SEI Structure in Li-Mediated N<sub>2</sub> Reduction Reaction.

Journal of the American Chemical Society·2026
Same journal

Solvent Esterification and Stoichiometric Control in Ambient-Grown FAPbI<sub>3</sub> Single-Crystal Solar Cells.

Journal of the American Chemical Society·2026
Same journal

Unlocking Azulene Functionalization via Strain-Induced Azulyne Intermediates.

Journal of the American Chemical Society·2026
Same journal

An Oxazine-Locked Covalent Organic Framework by a Tandem Pinner/Schiff Base Reaction for Hydrogen Peroxide Photosynthesis.

Journal of the American Chemical Society·2026
See all related articles

Related Experiment Video

Updated: Jun 27, 2025

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions
10:21

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions

Published on: October 5, 2019

8.4K

Intermolecular Proton-Coupled Electron Transfer Reactivity from a Persistent Charge-Transfer State for Reductive

Pablo Garrido-Barros1, Catherine G Romero1, Jay R Winkler1

  • 1Division of Chemistry and Chemical Engineering, California Institute of Technology (Caltech), Pasadena, California 91125, United States.

Journal of the American Chemical Society
|April 26, 2024
PubMed
Summary
This summary is machine-generated.

Researchers developed a novel ferrocene-derived mediator for proton-coupled electron transfer (PCET) catalysis. This mediator features a long-lived excited state, enabling efficient reductive transformations and mitigating hydrogen evolution.

More Related Videos

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
09:12

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Published on: May 21, 2019

9.2K
Characterizing Electron Transport through Living Biofilms
08:52

Characterizing Electron Transport through Living Biofilms

Published on: June 1, 2018

8.4K

Related Experiment Videos

Last Updated: Jun 27, 2025

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions
10:21

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions

Published on: October 5, 2019

8.4K
[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
09:12

[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst

Published on: May 21, 2019

9.2K
Characterizing Electron Transport through Living Biofilms
08:52

Characterizing Electron Transport through Living Biofilms

Published on: June 1, 2018

8.4K

Area of Science:

  • Photochemistry
  • Electrochemistry
  • Catalysis

Background:

  • Proton-coupled electron transfer (PCET) is crucial for reductive catalysis.
  • A major challenge is suppressing the competing hydrogen evolution reaction.
  • Developing mediators with long-lived excited states is essential for efficient PCET.

Purpose of the Study:

  • To design and characterize a novel photoelectrochemical PCET mediator.
  • To investigate strategies for mitigating hydrogen evolution in PCET reactions.
  • To demonstrate the utility of the new mediator in reductive transformations.

Main Methods:

  • Synthesis of a ferrocene-derived PCET mediator.
  • Detailed photophysical studies to determine excited state lifetime.
  • Stoichiometric and catalytic proton-coupled reductive transformations.

Main Results:

  • The developed mediator exhibits an unusually long-lived charge-separated state (CSS) with a lifetime of approximately 0.9 μs.
  • Proof-of-concept stoichiometric and catalytic reductive transformations were successfully demonstrated.
  • The mediator effectively facilitates PCET while minimizing hydrogen evolution.

Conclusions:

  • Ferrocene-derived mediators with long-lived CSS offer a promising strategy for efficient PCET catalysis.
  • This approach can overcome limitations posed by the hydrogen evolution reaction.
  • The developed mediator shows significant potential for applications in reductive electro- and photocatalysis.