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

Electron Transport Chain: Complex III and IV01:43

Electron 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
Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

3.3K
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.
3.3K
Cycloaddition Reactions: MO Requirements for Photochemical Activation01:12

Cycloaddition Reactions: MO Requirements for Photochemical Activation

2.9K
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
2.9K
Valence Bond Theory02:42

Valence Bond Theory

11.8K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
11.8K
The Electron Transport Chain01:30

The Electron Transport Chain

21.7K
The electron transport chain or oxidative phosphorylation is an exothermic process in which free energy released during electron transfer reactions is coupled to ATP synthesis. This process is a significant source of energy in aerobic cells, and therefore inhibitors of the electron transport chain can be detrimental to the cell's metabolic processes.
Inhibitors of the electron transport chain
Rotenone, a widely used pesticide, prevents electron transfer from Fe-S cluster to ubiquinone or Q...
21.7K
Woodward–Hoffmann Selection Rules and Microscopic Reversibility01:34

Woodward–Hoffmann Selection Rules and Microscopic Reversibility

4.2K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
4.2K

You might also read

Related Articles

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

Sort by
Same author

Brain-wide mapping reveals temporal and sexually dimorphic opioid actions.

Communications biology·2026
Same author

Sex-specific transcriptional signatures of oxycodone persist during withdrawal and abstinence in the suprachiasmatic nucleus of heterogeneous stock rats.

Addiction neuroscience·2026
Same author

Sex-specific transcriptional signatures of oxycodone persist during withdrawal and abstinence in the suprachiasmatic nucleus of heterogeneous stock rats.

bioRxiv : the preprint server for biology·2025
Same author

SleepInvestigatoR: a flexible R function for analyzing scored sleep in rodents.

Sleep advances : a journal of the Sleep Research Society·2025
Same author

Molybdenum Cofactor Model Reveals Remarkable Redox Activity at Both Molybdenum and the Pyranopterin Dithiolene Ligand.

Journal of the American Chemical Society·2025
Same author

Sex-Specific Concordance of Striatal Transcriptional Signatures of Opioid Addiction in Human and Rodent Brains.

Biological psychiatry global open science·2025
Same journal

Solvent Coordination-Induced Synergistic Phase, Facet, and Defect Engineering of CdS for Photocatalytic Hydrogen Evolution.

Inorganic chemistry·2026
Same journal

Tailoring the Electron-Enriched Microenvironment of UiO-66 via Thiol Functionalization to Boost Non-Thermal Plasma CO<sub>2</sub> Conversion.

Inorganic chemistry·2026
Same journal

Nonporous Self-Assembled Pd(II) Coordination Cage Enabling Dual Capture of Iodine and Methyl Iodide.

Inorganic chemistry·2026
Same journal

A Three-Dimensional Organic-Inorganic Hybrid Perovskite-Type Molecular Ferroelectric Material [3.2.2-H<sub>2</sub>dabcn]Rb(NO<sub>3</sub>)<sub>3</sub>.

Inorganic chemistry·2026
Same journal

Nonlinear Optical-Active NaAlP<sub>2</sub>S<sub>6</sub> Synthesized by the MOBQ Method: Synthesis, Structure, and Optical Properties.

Inorganic chemistry·2026
Same journal

Ligand-Controlled Redox and Photophysical Properties in Photoluminescent Tris-Heteroleptic Ru(II) Pyridyl-Phosphonium Ylide Complexes.

Inorganic chemistry·2026
See all related articles

Related Experiment Video

Updated: Apr 13, 2026

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

9.1K

Solvent-Dependent Pyranopterin Cyclization in Molybdenum Cofactor Model Complexes.

Benjamin R Williams1, Douglas Gisewhite1, Anna Kalinsky1

  • 1Department of Chemistry, Bryn Mawr College , Bryn Mawr, Pennsylvania 19010, United States.

Inorganic Chemistry
|May 6, 2015
PubMed
Summary
This summary is machine-generated.

Molybdenum cofactor (Moco) ring-chain tautomerism was studied in model complexes. Solvent polarity influences the equilibrium, with polar solvents favoring the pyranopterin dithiolene form.

More Related Videos

Preparation of SNS CobaltII Pincer Model Complexes of Liver Alcohol Dehydrogenase
06:31

Preparation of SNS CobaltII Pincer Model Complexes of Liver Alcohol Dehydrogenase

Published on: March 19, 2020

7.8K
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

Related Experiment Videos

Last Updated: Apr 13, 2026

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

9.1K
Preparation of SNS CobaltII Pincer Model Complexes of Liver Alcohol Dehydrogenase
06:31

Preparation of SNS CobaltII Pincer Model Complexes of Liver Alcohol Dehydrogenase

Published on: March 19, 2020

7.8K
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

Area of Science:

  • Bioinorganic Chemistry
  • Enzyme Catalysis
  • Structural Biology

Background:

  • The molybdenum cofactor (Moco) contains a pterin dithiolene ligand crucial for mononuclear Mo enzymes.
  • This ligand exists in tricyclic pyranopterin dithiolene and bicyclic pterin-dithiolene forms.
  • Interconversion between these forms is hypothesized to be key to Moco's catalytic mechanism.

Purpose of the Study:

  • To investigate the ring-chain tautomerism of the Moco ligand.
  • To quantify the equilibrium, enthalpy, entropy, and free energy of this process in model complexes.
  • To understand the influence of solvent polarity on the tautomeric equilibrium.

Main Methods:

  • Synthesis of two Moco model complexes: (Et4N)[Tp*Mo(O)(S2BMOPP)] and (Et4N)[Tp*Mo(O)(S2PEOPP)].
  • Analysis of solvent-dependent equilibrium constants (Keq) using 1H NMR spectroscopy in seven deuterated solvents.
  • Thermodynamic analysis including enthalpy, entropy, and free energy calculations.

Main Results:

  • Equilibrium constants (Keq) were determined for the pyran ring tautomerism in the model complexes.
  • A correlation was observed between solvent polarity and the tautomer distribution.
  • Higher solvent polarity parameters favored the tricyclic pyranopterin dithiolene form.

Conclusions:

  • The study provides thermodynamic data for Moco ligand tautomerism.
  • Solvent polarity is a significant factor modulating the equilibrium between pyranopterin and pterin-dithiolene forms.
  • Understanding this tautomerism is vital for elucidating the catalytic mechanisms of Moco-dependent enzymes.