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 Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals01:17

Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals

2.5K
Ideally, an unpaired electron shows a single peak in the EPR spectrum due to the transition between the two spin energy states. However, coupling interactions can occur between the spins of the unpaired electron and any neighboring spin-active nuclei. This hyperfine coupling results in hyperfine splitting, where the EPR signal is split into multiplets. The signals split into 2nI + 1 peaks, where n is the number of equivalent nuclei and I is the nuclear spin. These splitting patterns provide...
2.5K
¹H NMR: Complex Splitting01:13

¹H NMR: Complex Splitting

1.3K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
1.3K
¹H NMR: Interpreting Distorted and Overlapping Signals01:02

¹H NMR: Interpreting Distorted and Overlapping Signals

1.0K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.0K
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule01:10

Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule

1.3K
In the AX proton spin system, proton A can sense the two spin states of a coupled proton X, resulting in a doublet NMR signal with two peaks of equal (1:1) intensity. When proton A is coupled to two equivalent protons (AX2 spin system), the spin states of each X can be aligned with or against the external field, creating three possible scenarios. This results in a 1:2:1  triplet signal, where the central peak corresponds to the chemical shift of A and is twice as large or intense as the...
1.3K
Valence Bond Theory02:42

Valence Bond Theory

8.6K
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...
8.6K
Colors and Magnetism03:02

Colors and Magnetism

11.7K
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...
11.7K

You might also read

Related Articles

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

Sort by
Same author

Synthesis of Tetrakis(amino)ethylene-Derived Organic Reductants via Thermal Decomposition of Tris(amino)methanes.

Organic letters·2026
Same author

Spectroscopic Characterization of Tetravalent Berkelium.

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

Unexpected dispersion-stabilized tris(terphenylthiolate) complexes, Ln(SAr <sup><i>i</i>Pr6</sup>)<sub>3</sub>, arising from two-electron reduction by Ln(SAr <sup><i>i</i>Pr6</sup>)<sub>2</sub> [Ar <sup><i>i</i>Pr6</sup> = C<sub>6</sub>H<sub>3</sub>-2,6-(C<sub>6</sub>H<sub>2</sub>-2,6,4- <sup><i>i</i></sup> Pr<sub>3</sub>)<sub>2</sub>].

Chemical science·2026
Same author

Isolable Cuprocenes: Bis(tri-<i>tert</i>-butylcyclopentadienyl) Complexes of Copper.

Journal of the American Chemical Society·2026
Same author

<i>In crystallo</i> homolytic cleavage of a terminal lanthanum(III)-methyl bond by Cu Kα X-radiation forms a La(II) complex.

Chemical communications (Cambridge, England)·2025
Same author

On the Use of Ce[N(SiMe<sub>3</sub>)<sub>2</sub>]<sub>3</sub>(THF)<sub><i>n</i></sub> in Catalysis.

Inorganic chemistry·2025

Related Experiment Video

Updated: Jul 4, 2025

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

26.5K

Perplexing EPR Signals from 5f36d1 U(II) Complexes.

Justin C Wedal1, William N G Moore1, Wayne W Lukens2

  • 1Department of Chemistry, University of California Irvine, Irvine, California 92697, United States.

Inorganic Chemistry
|January 27, 2024
PubMed
Summary

Unusual metal complexes with f and d electrons were studied using electron paramagnetic resonance (EPR). Unexpected EPR signals were observed for Uranium(II) complexes, differentiating them from other configurations.

More Related Videos

Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F&#8722;
06:53

Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−

Published on: July 27, 2018

8.7K
An Experimental Protocol for Femtosecond NIR/UV - XUV Pump-Probe Experiments with Free-Electron Lasers
09:49

An Experimental Protocol for Femtosecond NIR/UV - XUV Pump-Probe Experiments with Free-Electron Lasers

Published on: October 23, 2018

16.0K

Related Experiment Videos

Last Updated: Jul 4, 2025

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

26.5K
Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F&#8722;
06:53

Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−

Published on: July 27, 2018

8.7K
An Experimental Protocol for Femtosecond NIR/UV - XUV Pump-Probe Experiments with Free-Electron Lasers
09:49

An Experimental Protocol for Femtosecond NIR/UV - XUV Pump-Probe Experiments with Free-Electron Lasers

Published on: October 23, 2018

16.0K

Area of Science:

  • Inorganic Chemistry
  • Spectroscopy
  • Quantum Mechanics

Background:

  • Metal complexes with unpaired electrons in f and d orbitals are rare, limiting studies on their interactions.
  • Understanding electron configurations and their magnetic properties is crucial in inorganic chemistry.

Purpose of the Study:

  • To investigate the electron paramagnetic resonance (EPR) behavior of Uranium(II) complexes with 5f^3 6d^1 electron configurations.
  • To compare the EPR spectra of Uranium(II) complexes with analogous light actinide and lanthanide complexes.
  • To explore the influence of f and d electron coupling on EPR signal generation.

Main Methods:

  • X-band electron paramagnetic resonance (EPR) spectroscopy was employed.
  • Measurements were conducted at low temperatures (<10 K and 77 K).
  • Complexes studied included Uranium(II) with 5f^3 6d^1 and 5f^4 configurations, and Ce(II), Pr(II), Nd(II) with 4f^n 5d^1 configurations.

Main Results:

  • Uranium(II) complexes with 5f^3 6d^1 configurations unexpectedly showed axial EPR signals (g|| = 2.04, g⊥ = 2.00) at 77 K.
  • Uranium(II) complexes with 5f^4 configurations were EPR-silent.
  • Analogous lanthanide complexes (Ce, Pr, Nd) exhibited varied EPR activity, with Pr(II) showing a signal while Ce(II) and Nd(II) were silent.

Conclusions:

  • The observed EPR signals in 5f^3 6d^1 Uranium(II) complexes are currently unexplained, as strong f-d coupling was predicted to yield silent compounds.
  • EPR spectroscopy can effectively differentiate between Uranium(II) complexes with 5f^3 6d^1 and 5f^4 electron configurations.
  • The study highlights the complex interplay between electron configuration and magnetic properties in heavy metal complexes.