Related Experiment Video

Updated: May 15, 2026

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines
05:07

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines

Published on: June 23, 2019

N-N migration of a carbamoyl group in a pyrazole derivative revealed by NMR

Charles Pathirana, Chris Sfouggatakis, Venkatapuram Palaniswamy

    Magnetic Resonance in Chemistry : MRC
    |January 23, 2013
    PubMed

    More Related Videos

    Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine11:04

    Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine

    Published on: June 13, 2022

    Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry09:37

    Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry

    Published on: October 18, 2019

    Related Concept Videos

    Spectroscopy of Carboxylic Acid Derivatives01:26

    Spectroscopy of Carboxylic Acid Derivatives

    Infrared spectroscopy is primarily used to determine the types of bonds and functional groups. In carboxylic acid derivatives, a typical carbonyl bond absorption is observed around 1650–1850 cm−1. For esters, the absorption is recorded at around 1740 cm−1, while acid halides show the absorption at about 1800 cm−1. Another acid derivative, the acid anhydrides, exhibit two carbonyl absorption around 1760 cm−1 and 1820 cm−1, arising from the symmetrical and unsymmetrical carbonyl vibration.
    In the...
    ¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR01:15

    ¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR

    The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
    NMR Spectroscopy of Aromatic Compounds01:14

    NMR Spectroscopy of Aromatic Compounds

    Aromatic compounds can be identified or analyzed using proton NMR and carbon‐13 NMR. Typically, aromatic hydrogens or hydrogens directly bonded to the aromatic rings are strongly deshielded by the aromatic ring current. Therefore, they absorb in the range of 6.5–8.0 ppm in proton NMR spectra. For instance, aromatic hydrogens directly bonded to the benzene ring absorb at 7.3 ppm. However, aromatic hydrogens of larger rings absorb farther upfield or downfield than the ideal range. Consider...
    NMR Spectroscopy of Benzene Derivatives01:37

    NMR Spectroscopy of Benzene Derivatives

    Simple unsubstituted benzene has six aromatic protons, all chemically equivalent. Therefore, benzene exhibits only a singlet peak at δ 7.3 ppm in the 1H NMR spectrum. The observed shift is far downfield because the aromatic ring current strongly deshields the protons. Any substitution on the benzene ring makes the aromatic protons nonequivalent, and the protons split each other. The peak is, therefore, no longer a singlet and the splitting pattern and their associated coupling constants depend...
    ¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)01:20

    ¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)

    When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
    Structures of Carboxylic Acid Derivatives01:28

    Structures of Carboxylic Acid Derivatives

    Structure of Carboxylic Acid Derivatives
    Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
    The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...