Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Photochemical Electrocyclic Reactions: Stereochemistry

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation

Hybridization of Atomic Orbitals II

Hybridization of Atomic Orbitals II

sp3d and sp3d 2 Hybridization

Aryldiazonium Salts to Azo Dyes: Diazo Coupling

Aryldiazonium Salts to Azo Dyes: Diazo Coupling

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 position.

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as annulenes. In...

Atomic Emission Spectroscopy: Overview

Atomic Emission Spectroscopy: Overview

Atomic emission spectroscopy (AES) is an analytical technique used to determine the elemental composition of a sample by analyzing the light emitted from excited atoms. In AES, atoms in a sample are excited to higher energy levels by thermal energy from high-temperature sources, such as plasma, arcs, or sparks. When these excited atoms return to lower energy states, they emit light at specific wavelengths characteristic of each element. The resulting atomic emission spectrum, which consists of...

Basicity of Heterocyclic Aromatic Amines

Basicity of Heterocyclic Aromatic Amines

Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8).

You might also read

Related Articles

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

Sort by

Same author

Retraction notice to "PIM1 kinase inhibitors induce radiosensitization in non-small cell lung cancer cells" [Pharmacol. Res. 70 (2013) 90-101].

Pharmacological research·2026

Same author

The Role of Chemistry Across Disciplines From Humanities to Life Sciences in Understanding Complexity and Emergence.

Angewandte Chemie (International ed. in English)·2026

Same author

PHY domain governs structural and photochemical fidelity in the far-red-absorbing state of phytochromes.

Frontiers in molecular biosciences·2026

Same author

Switching Shapes: Reversible Three Species Photoisomerization of Substituted 1,2-Dihydro-1,2-azaborinines.

Journal of the American Chemical Society·2026

Same author

Diverging pH dependence and photocycle dynamics across members of the CryoRhodopsin clade.

Biophysical journal·2026

Same author

Dispersion-Controlled Excited-State Dynamics in Azobenzene Photoisomerization.

Journal of the American Chemical Society·2025

Search research articles

Related Experiment Video

Updated: Jul 14, 2026

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H₂ Production in Aqueous Aerobic Conditions

Published on: October 5, 2019

RNA as scaffold for pyrene excited complexes.

Christian Grünewald¹, Taewoo Kwon, Nelly Piton

¹Institute of Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University, Max-von-Laue-Str. 7, 60348 Frankfurt, Germany.

Bioorganic & Medicinal Chemistry

|May 22, 2007

Summary

Researchers synthesized pyrene-modified RNA, enabling fluorescence spectroscopy to distinguish single and double strands. This method allows for kinetic studies of RNA hybridization and folding.

More Related Videos

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach

Published on: June 10, 2021

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

Related Experiment Videos

Last Updated: Jul 14, 2026

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H₂ Production in Aqueous Aerobic Conditions

Published on: October 5, 2019

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach

Published on: June 10, 2021

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

Area of Science:

Biochemistry
Molecular Biology
Spectroscopy

Background:

RNA structure and dynamics are crucial for biological function.
Fluorescent labeling is a powerful tool for studying nucleic acids.
Developing novel probes for RNA analysis is an ongoing area of research.

Purpose of the Study:

To synthesize and characterize 1-ethynylpyrene modified RNA.
To investigate the spectral properties of the modified RNA.
To establish a fluorescence-based method for distinguishing RNA single and double strands and studying RNA kinetics.

Main Methods:

Chemical synthesis of 1-ethynylpyrene base-modified adenosine.
Incorporation of the modified base into RNA strands.
Fluorescence spectroscopy to analyze spectral properties and distinguish strand types.
Kinetic measurements of RNA hybridization and folding.

Main Results:

Successful synthesis of pyrene-modified RNA.
The pyrene fluorophore is directed into the minor groove of RNA.
Distinct fluorescence emission maxima observed for single (approx. 450 nm) and double strands (approx. 480 nm).
Demonstrated ability to monitor RNA hybridization and folding kinetics via fluorescence changes.

Conclusions:

1-ethynylpyrene modified RNA serves as an effective fluorescent probe.
The method allows for real-time, non-invasive monitoring of RNA structural transitions.
This approach has potential applications in studying RNA-protein interactions and drug discovery.