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

¹H NMR of Conformationally Flexible Molecules: Temporal Resolution00:52

¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

815
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
815
UV–Vis Spectroscopy: Molecular Electronic Transitions01:16

UV–Vis Spectroscopy: Molecular Electronic Transitions

1.4K
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this...
1.4K
¹H NMR of Labile Protons: Temporal Resolution01:10

¹H NMR of Labile Protons: Temporal Resolution

1.1K
Protons bonded to heteroatoms such as nitrogen and oxygen exhibit a range of chemical shift values. This is due to the varying degree of hydrogen bonding between the proton and the heteroatom in other molecules. The extent of hydrogen bonding affects the electron density around the proton, thereby giving different chemical shift values for the protons in the proton NMR spectrum.
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
1.1K
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)01:19

2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)

662
Heteronuclear single-quantum correlation spectroscopy (HSQC) is a 2D NMR technique that reveals one-bond correlations between hydrogen and a heteronucleus. The HSQC experiment is similar to the heteronuclear correlation experiment (HETCOR) but is more sensitive. In the HSQC spectrum, the proton chemical shift is plotted on the horizontal F2 axis, while the 13C chemical shift is plotted on the vertical F1 axis. The corresponding proton and 13C spectra are also shown. The HSQC contour plot does...
662
Molecular Spectroscopy: Absorption and Emission01:14

Molecular Spectroscopy: Absorption and Emission

1.9K
Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational and vibrational energy levels.  Each energy level is separated by an energy gap, with the gaps between adjacent electronic, vibrational, and rotational levels varying significantly. The three types of energy levels in a diatomic molecule are shown in Figure 1.
1.9K
2D NMR: Overview of Heteronuclear Correlation Techniques01:18

2D NMR: Overview of Heteronuclear Correlation Techniques

163
Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
163

You might also read

Related Articles

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

Sort by
Same author

Continuous-Time Quantum-Walk Centrality for Protein Residue Interaction Networks.

Journal of the American Chemical Society·2026
Same author

A Retrospective Analysis of Deep Tissue Pressure Injury Prevalence and Incidence Using a Large-scale Wound Care Database in Long-term Care Settings Across North America.

Advances in skin & wound care·2026
Same author

Joseph S. Francisco: A Biographical Sketch.

The journal of physical chemistry. A·2026
Same author

Tribute to Joseph S. Francisco.

The journal of physical chemistry. A·2026
Same author

Redefining ·CO<sub>3</sub><sup>-</sup> Formation Chemistry: Zundel-like Switches Drive Carbonate-·OH Interfacial Reactivity.

Journal of the American Chemical Society·2026
Same author

Graphdiyne confined-membrane with intrinsic in-plane-pores for angstrom-scale gas sieving.

Nature communications·2026
Same journal

Real-Time Vibrational Spectroscopy Reveals an Inversion Transition State in the Photoisomerization of Phenylazoimidazole.

The journal of physical chemistry letters·2026
Same journal

Precursor-Directed Self-Assembly in Hydrothermal Carbon Nitride Nanostructures Revealed by Nano-FTIR.

The journal of physical chemistry letters·2026
Same journal

Correction to "Equation-of-Motion Block-Correlated Coupled Cluster Method for Excited Electronic States of Strongly Correlated Systems".

The journal of physical chemistry letters·2026
Same journal

Rationalizing Stacking-Dependent Charge Injection Dynamics in Radical-Based Organic Light-Emitting Diodes.

The journal of physical chemistry letters·2026
Same journal

Bottom-Up Formation of the Simplest Geminal Thiol─Methanedithiol (CH<sub>2</sub>(SH)<sub>2</sub>)─and the Methyl Hydrodisulfide (H<sub>3</sub>CSSH) Isomer in Interstellar Analogue Ices.

The journal of physical chemistry letters·2026
Same journal

Trion Mediated Sequential Charge Separation in Functionalized CsPbBr<sub>3</sub>/AgInS<sub>2</sub> Hybrid Nanocrystals.

The journal of physical chemistry letters·2026
See all related articles

Related Experiment Video

Updated: Jun 13, 2025

Author Spotlight: Exploring Light-Driven Chemical Reactions and Energy-Harnessing Devices in Photochemical Research
08:12

Author Spotlight: Exploring Light-Driven Chemical Reactions and Energy-Harnessing Devices in Photochemical Research

Published on: February 16, 2024

8.7K

Time Resolved Quantum Tomography in Molecular Spectroscopy by the Maximal Entropy Approach.

Varun Makhija1, Rishabh Gupta2, Simon Neville3

  • 1Department of Chemistry and Physics, University of Mary Washington, Fredericksburg, Virginia 22401, United States.

The Journal of Physical Chemistry Letters
|September 12, 2024
PubMed
Summary
This summary is machine-generated.

Quantum state tomography reveals the role of electron coherences in photochemical reactions. This study quantifies electronic entanglement entropy, offering new insights into ultrafast molecular dynamics.

More Related Videos

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
10:40

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy

Published on: June 28, 2016

7.5K
Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules
10:23

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules

Published on: April 25, 2025

215

Related Experiment Videos

Last Updated: Jun 13, 2025

Author Spotlight: Exploring Light-Driven Chemical Reactions and Energy-Harnessing Devices in Photochemical Research
08:12

Author Spotlight: Exploring Light-Driven Chemical Reactions and Energy-Harnessing Devices in Photochemical Research

Published on: February 16, 2024

8.7K
High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
10:40

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy

Published on: June 28, 2016

7.5K
Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules
10:23

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules

Published on: April 25, 2025

215

Area of Science:

  • Ultrafast molecular spectroscopy
  • Quantum information science
  • Photochemistry

Background:

  • Attosecond science precisely probes initial chemical reaction moments.
  • Understanding quantum coherences in electron states is crucial for photochemical reactions.

Purpose of the Study:

  • To apply Maximal Entropy (MaxEnt) based Quantum State Tomography (QST) to photoexcited ammonia.
  • To determine the role of quantum coherences in photochemical reactions.
  • To quantify electronic entanglement entropy in molecular systems.

Main Methods:

  • Developed two methodologies for constructing operator forms of observables using Molecular Angular Distribution Moments (MADMs) and Angular Momentum Coherence Operators.
  • Applied MaxEnt-based QST to photoexcited ammonia with partial tomographic data.
  • Visualized electron density and charge migration within the molecular frame.

Main Results:

  • Established a direct link between Lagrange multipliers in MaxEnt and MADMs.
  • Successfully visualized charge migration in photoexcited ammonia.
  • Quantified electronic entanglement entropy for the first time, revealing electron-nuclear coupling effects.

Conclusions:

  • MaxEnt-based QST is effective for studying molecular dynamics, even with partial data.
  • The developed methods enable visualization of electron density and quantification of entanglement.
  • Findings advance ultrafast molecular spectroscopy and quantum information science applications in studying excited molecular systems.