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

Cycloaddition Reactions: MO Requirements for Photochemical Activation01:12

Cycloaddition Reactions: MO Requirements for Photochemical Activation

2.2K
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.
2.2K
The Antenna Complex01:15

The Antenna Complex

6.2K
Plants and other photosynthetic organisms comprise pigments capable of absorption of direct sunlight. These pigments are present in the reaction center - the main site of photochemical reactions as well as in the antenna complex. Under average light conditions, the rate at which reaction center pigments absorb light is far below the electron transport chain's capacity. As a result, the reaction center alone cannot provide enough energy to drive photosynthesis. The photosynthetic efficiency can...
6.2K
Nuclear Overhauser Enhancement (NOE)01:07

Nuclear Overhauser Enhancement (NOE)

791
Irradiation of a spin-active nucleus causes an increase or decrease in the signal intensity of neighboring nuclei that are not necessarily chemically bonded or involved in J-coupling.  This phenomenon, called the Nuclear Overhauser Enhancement (NOE), results from through-space interactions between the nuclear spins. The NOE effect decreases with increasing internuclear distance and is generally not observed beyond 4 angstroms. In NOE, dipole-dipole interactions between neighboring...
791
Atomic Absorption Spectroscopy: Interference01:25

Atomic Absorption Spectroscopy: Interference

970
Interference leads to systematic error in atomic absorption (AA) measurements by enhancing or diminishing the analytical signal or the background. These interferences can be grouped into three main categories: spectral interference, chemical interference, and physical interference.
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
970
Deactivation Processes: Jablonski Diagram01:25

Deactivation Processes: Jablonski Diagram

829
Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...
829
Double Resonance Techniques: Overview01:12

Double Resonance Techniques: Overview

271
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
271

You might also read

Related Articles

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

Sort by
Same author

Unfolding of the Villin Headpiece Domain: Revealing Structural Heterogeneity with Time-Resolved X-Ray Solution Scattering and Markov State Modeling.

Chemphyschem : a European journal of chemical physics and physical chemistry·2025
Same author

Electronically Perturbed Vibrational Excitations of the Luminescing Stable Blatter Radical.

ACS nano·2025
Same author

Early Folding Dynamics of i-Motif DNA Revealed by pH-Jump Time-Resolved X-ray Solution Scattering.

Journal of the American Chemical Society·2024
Same author

Design rules for catalysis in single-particle plasmonic nanogap reactors with precisely aligned molecular monolayers.

Nature communications·2024
Same author

Hydrogen-Bonded Fibrous Nanotubes Assembled from Trigonal Prismatic Building Blocks.

Journal of the American Chemical Society·2024
Same author

Unlocking the unfolded structure of ubiquitin: Combining time-resolved x-ray solution scattering and molecular dynamics to generate unfolded ensembles.

The Journal of chemical physics·2024

Related Experiment Video

Updated: Aug 26, 2025

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
08:04

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

8.5K

Controlling Aggregation-Induced Two-Photon Absorption Enhancement via Intermolecular Interactions.

Charles J Zeman1, Gyeongwon Kang1, Kevin L Kohlstedt1

  • 1Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois60208, United States.

ACS Applied Materials & Interfaces
|October 3, 2022
PubMed
Summary

Computational methods reveal how molecular aggregation affects two-photon absorption (2PA) cross sections. Condensed-phase simulations show that dye stacking and conformational locking significantly alter 2PA, with J-aggregates enhancing and H-aggregates quenching activity.

Keywords:
aggregationdonor−acceptor moleculesexcited statesnonlinear opticsorganic dyes

More Related Videos

Measuring Diffusion Coefficients via Two-photon Fluorescence Recovery After Photobleaching
07:00

Measuring Diffusion Coefficients via Two-photon Fluorescence Recovery After Photobleaching

Published on: February 26, 2010

11.3K
Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light
11:26

Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light

Published on: September 12, 2014

12.7K

Related Experiment Videos

Last Updated: Aug 26, 2025

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
08:04

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

8.5K
Measuring Diffusion Coefficients via Two-photon Fluorescence Recovery After Photobleaching
07:00

Measuring Diffusion Coefficients via Two-photon Fluorescence Recovery After Photobleaching

Published on: February 26, 2010

11.3K
Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light
11:26

Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light

Published on: September 12, 2014

12.7K

Area of Science:

  • Physical Chemistry
  • Computational Chemistry
  • Materials Science

Background:

  • Two-photon absorption (2PA) cross sections are crucial optical properties for materials.
  • Traditional solution-phase measurements do not accurately reflect 2PA in condensed phases or aggregated states.
  • Understanding aggregation effects is vital for designing advanced optical materials.

Purpose of the Study:

  • To computationally investigate the impact of aggregation on 2PA cross sections of quadrupolar π-conjugated dyes.
  • To elucidate the molecular-level mechanisms governing 2PA changes in condensed phases.
  • To compare gas-phase and condensed-phase 2PA behaviors.

Main Methods:

  • Molecular dynamics (MD) simulations in both gas and condensed phases.
  • Characterization of intermolecular interactions and electronic coupling.
  • Calculation of 2PA cross sections using quadratic-response time-dependent density functional theory (QR-TDDFT).

Main Results:

  • Condensed-phase simulations revealed significant changes in 2PA cross sections compared to gas-phase values.
  • J-aggregates showed enhanced 2PA, while H-aggregates exhibited quenched 2PA.
  • Conformational locking was identified as a dominant factor influencing 2PA in disordered aggregates.

Conclusions:

  • Molecular aggregation and conformation play critical roles in determining 2PA cross sections.
  • Computational modeling provides accurate insights into 2PA behavior in condensed phases.
  • Findings guide the design of dyes with tailored optical properties for aggregation-dependent applications.