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

Colors and Magnetism03:02

Colors and Magnetism

14.7K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
14.7K
Aryldiazonium Salts to Azo Dyes: Diazo Coupling01:11

Aryldiazonium Salts to Azo Dyes: Diazo Coupling

4.2K
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para...
4.2K
EDTA: Auxiliary Complexing Reagents01:26

EDTA: Auxiliary Complexing Reagents

1.6K
EDTA titrations are usually carried out in highly basic conditions, where the fully deprotonated form of EDTA, Y4−, actively complexes with the free metal ions in the solution. Several metal ions precipitate as hydrous oxide (hydroxides, oxides, or oxyhydroxides) under these conditions, lowering the concentration of free metal ions in the solution. For this reason, auxiliary complexing agents or ligands such as ammonia, tartrate, citrate, or triethanolamine are used in EDTA titrations to...
1.6K
Redox Titration: Other Oxidizing and Reducing Agents01:26

Redox Titration: Other Oxidizing and Reducing Agents

1.8K
Besides iodine, other oxidizing or reducing agents can serve as titrants in redox titrations. Common oxidizing titrants include KMnO4, cerium(IV), and K2Cr2O7. The choice of oxidizing titrants depends on factors like stability, cost, analyte strength, and reaction rate between the analyte and titrant. KMnO4 is a strong oxidizing titrant that reduces from Mn(VII) to Mn(II) in a highly acidic solution, simultaneously oxidizing the analyte to a higher oxidation state. In this case, KMnO4 acts as a...
1.8K
Indicators02:39

Indicators

64.2K
Certain organic substances change color in dilute solution when the hydronium ion concentration reaches a particular value. For example, phenolphthalein is a colorless substance in any aqueous solution with a hydronium ion concentration greater than 5.0 × 10−9 M (pH < 8.3). In more basic solutions where the hydronium ion concentration is less than 5.0 × 10−9 M (pH > 8.3), it is red or pink. Substances such as phenolphthalein, which can be used to determine the pH of a solution, are...
64.2K
Oxymercuration-Reduction of Alkenes02:36

Oxymercuration-Reduction of Alkenes

9.9K
Oxymercuration–reduction of alkenes is one of the major reactions converting alkenes to alcohols. It involves the hydration of alkenes with mercuric acetate in a mixture of tetrahydrofuran and water, forming an organomercury adduct. This is followed by a demercuration step in which the adduct is reduced to an alcohol using sodium borohydride.
9.9K

You might also read

Related Articles

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

Sort by
Same author

Observing Kinetic Selectivity in Anthracene Photodimerization through Selective Quenching by Excited States of Proximate Rare Earth Cations.

Journal of the American Chemical Society·2026
Same author

Comparison of Bonding in Isostructural Cerium and Thorium Parent Amide Complexes.

Inorganic chemistry·2026
Same author

Probing the Redox Chemistry of Bimetallic Rare Earth-Catecholate Complexes.

Inorganic chemistry·2026
Same author

Metal-Dependent Photodissociation of Hydrazone Photoswitches from Rare-Earth Complexes.

Journal of the American Chemical Society·2026
Same author

Leveraging the redox activities of cerium and dibenzotetrathiafulvalene to discover a photo-responsive magnetic material.

Chemical science·2026
Same author

Realization of a Heteroatom-Transfer-Ligand (HTL) Platform: Oxy Insertion at a Titanium-Alkyl Bond Facilitated by a Hydroxylaminato Ligand Framework.

Angewandte Chemie (International ed. in English)·2025
Same journal

Thermally Induced In-Lattice Cation Transformation of 0D Antimony Halides for Improved X-ray Scintillation.

Inorganic chemistry·2026
Same journal

Low-Valent Rhodium and Iridium Assemblies Directed by Uracilate and Guaninate Linkers.

Inorganic chemistry·2026
Same journal

Solid-State Syntheses, Crystallographic Spatial Disorders, Thermal Behavior, and Bandgaps of Hybrid Organic-Inorganic Manganese Halides: A<sub>2</sub>Mn(Cl/Br)<sub>4</sub> (A = NH<sub>4</sub>, C(NH<sub>2</sub>)<sub>3</sub>, & C<sub>3</sub>H<sub>4</sub>N<sub>2</sub>).

Inorganic chemistry·2026
Same journal

Comparing the Photophysical Properties of Bridged and Unbridged Platinum(II) Cyclometalated Complexes.

Inorganic chemistry·2026
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
See all related articles

Related Experiment Video

Updated: Apr 12, 2026

Synthesis and Evaluation of a Ruthenium-based Mitochondrial Calcium Uptake Inhibitor
07:12

Synthesis and Evaluation of a Ruthenium-based Mitochondrial Calcium Uptake Inhibitor

Published on: October 26, 2017

8.3K

Why is uranyl formohydroxamate red?

Mark A Silver1, Walter L Dorfner2, Samantha K Cary1

  • 1†Department of Chemistry and Biochemistry, Florida State University, 102 Varsity Way, Tallahassee, Florida 32306, United States.

Inorganic Chemistry
|May 12, 2015
PubMed
Summary
This summary is machine-generated.

Uranium(VI) reacts with formohydroxamate (FHA) to form a dark red complex, not a U(V) species. This study reveals an unusually bent uranyl UO2(2+) unit due to strong ligand donation, altering its electronic and vibrational properties.

More Related Videos

U2O5 Film Preparation via UO2 Deposition by Direct Current Sputtering and Successive Oxidation and Reduction with Atomic Oxygen and Atomic Hydrogen
12:05

U2O5 Film Preparation via UO2 Deposition by Direct Current Sputtering and Successive Oxidation and Reduction with Atomic Oxygen and Atomic Hydrogen

Published on: February 21, 2019

8.6K
Methods for Analyzing the Impacts of Natural Uranium on In Vitro Osteoclastogenesis
09:51

Methods for Analyzing the Impacts of Natural Uranium on In Vitro Osteoclastogenesis

Published on: January 30, 2018

8.6K

Related Experiment Videos

Last Updated: Apr 12, 2026

Synthesis and Evaluation of a Ruthenium-based Mitochondrial Calcium Uptake Inhibitor
07:12

Synthesis and Evaluation of a Ruthenium-based Mitochondrial Calcium Uptake Inhibitor

Published on: October 26, 2017

8.3K
U2O5 Film Preparation via UO2 Deposition by Direct Current Sputtering and Successive Oxidation and Reduction with Atomic Oxygen and Atomic Hydrogen
12:05

U2O5 Film Preparation via UO2 Deposition by Direct Current Sputtering and Successive Oxidation and Reduction with Atomic Oxygen and Atomic Hydrogen

Published on: February 21, 2019

8.6K
Methods for Analyzing the Impacts of Natural Uranium on In Vitro Osteoclastogenesis
09:51

Methods for Analyzing the Impacts of Natural Uranium on In Vitro Osteoclastogenesis

Published on: January 30, 2018

8.6K

Area of Science:

  • Inorganic Chemistry
  • Uranium Chemistry
  • Coordination Chemistry

Background:

  • Uranium(VI) complexation with ligands can lead to redox activity and color changes.
  • Formohydroxamate (FHA) is a ligand with inherent redox activity.
  • Red coloration in uranyl solutions often suggests the presence of U(V) species.

Purpose of the Study:

  • To investigate the reaction products of Uranium(VI) with formohydroxamate (FHA).
  • To determine if the observed red coloration indicates U(V) formation or a different structural phenomenon.
  • To characterize the coordination environment and structural features of the resulting uranyl complex.

Main Methods:

  • Spectroscopic analysis of uranyl-formohydroxamate solutions.
  • X-ray crystallography to determine solid-state structure.
  • Computational analysis of electronic and bonding interactions.

Main Results:

  • The reaction of U(VI) with FHA does not result in reduction to U(V).
  • Formation of a cis-aquo UO2(FHA)2(H2O)2 complex in solution and a polymeric UO2(FHA)2 structure in the solid state.
  • The uranyl UO2(2+) unit exhibits unusual bending due to strong π donation from FHA(-) ligands.
  • The coordination environment around the U(VI) cation is highly distorted.

Conclusions:

  • The dark red color arises from a U(VI) complex, not U(V).
  • Strong π donation from formohydroxamate ligands significantly impacts the uranyl bond and coordination geometry.
  • The altered bonding in the uranyl unit leads to distinct electronic and vibrational characteristics.