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

Phase II Conjugation Reactions: Overview01:14

Phase II Conjugation Reactions: Overview

Conjugation, a key component of phase II biotransformation reactions, is a vital process in drug detoxification. It involves transferring endogenous substances like glucuronic acid, sulfate, and glycine to drugs or their metabolites formed in phase I reactions. These conjugation reactions, often catalyzed by specific enzymes, transform potentially harmful metabolites into inactive, water-soluble forms easily excreted in urine or bile. By enhancing polarity and eliminating pharmacological...
Photochemical Electrocyclic Reactions: Stereochemistry01:26

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
Aryldiazonium Salts to Azo Dyes: Diazo Coupling01:11

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.
Phase II Reactions: Miscellaneous Conjugation Reactions01:19

Phase II Reactions: Miscellaneous Conjugation Reactions

Phase II biotransformations are detoxification mechanisms that conjugate xenobiotics with endogenous substances, neutralizing their toxicity.
A key example involves the conjugation of cyanide ions, which impair cellular respiration and alter hemoglobin into non-oxygen-carrying cyanmethemoglobin. To neutralize this threat, a sulfur atom from thiosulphate is transferred to the cyanide ion, catalyzed by the enzyme rhodanese, resulting in an inactive compound called thiocyanate. The production of...
¹H NMR: Long-Range Coupling01:27

¹H NMR: Long-Range Coupling

The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
π Molecular Orbitals of 1,3-Butadiene01:24

π Molecular Orbitals of 1,3-Butadiene

Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...

You might also read

Related Articles

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

Sort by
Same author

Pooled safety analysis of zanubrutinib monotherapy in Asian patients with B-cell malignancies.

ESMO open·2026
Same author

[MRI comparison of brain region volumes between welding fumes exposed and non-exposed workers].

Zhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases·2026
Same author

[The application of large language models in the diagnosis of clinically significant prostate cancer].

Zhonghua wai ke za zhi [Chinese journal of surgery]·2026
Same author

Double-tube end ileostomy: an alternative to classical defunctioning stoma in rectal surgery.

Techniques in coloproctology·2025
Same author

[CDYL deficiency promotes vascular smooth muscle cell phenotypic switching through H3K18 crotonylation-mediated SGK1 transcriptional activation].

Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine]·2025
Same author

[Function evaluation of urinary, bowel, pelvic floor functions of patients after nerve-sparing radical hysterectomy based on CC-PRO137 scale].

Zhonghua yi xue za zhi·2025

Related Experiment Video

Updated: Jun 19, 2026

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
14:11

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

Published on: June 10, 2021

Low-power phase conjugation in push-pull azobenzene compounds.

H Fei, Z Wei, Q Yang

    Optics Letters
    |October 29, 2009
    PubMed
    Summary

    Push-pull azobenzene compounds exhibit significant third-order optical nonlinearity. These polymers show potential for applications in nonlinear optics due to their high chi((3)) values.

    More Related Videos

    High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
    06:24

    High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal

    Published on: October 31, 2019

    Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
    09:33

    Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch

    Published on: February 7, 2022

    Related Experiment Videos

    Last Updated: Jun 19, 2026

    Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
    14:11

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

    Published on: June 10, 2021

    High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
    06:24

    High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal

    Published on: October 31, 2019

    Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
    09:33

    Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch

    Published on: February 7, 2022

    Area of Science:

    • Materials Science
    • Optics and Photonics
    • Polymer Chemistry

    Background:

    • Push-pull azobenzene compounds are known for their photoresponsive properties.
    • Poly(methyl methacrylate) (PMMA) is a versatile polymer matrix for optical applications.

    Purpose of the Study:

    • To synthesize novel push-pull azobenzene compounds.
    • To investigate the third-order optical nonlinearity of azobenzene-doped PMMA films.

    Main Methods:

    • Diazocoupling reaction for azobenzene synthesis.
    • Fabrication of polymer films doped with synthesized compounds.
    • Low-power phase conjugation measurements using a He-Ne laser (632.8 nm).

    Main Results:

    • Successful synthesis of push-pull azobenzene compounds.
    • Azobenzene-doped PMMA films demonstrated appreciable third-order optical nonlinearity.
    • Measured third-order nonlinear susceptibility (chi((3))) of approximately 10(-4) esu in the absorption tail.

    Conclusions:

    • The synthesized azobenzene compounds are suitable for creating nonlinear optical materials.
    • PMMA-based composites exhibit promising nonlinear optical properties.
    • These materials hold potential for applications in optical devices requiring third-order nonlinearity.