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

Structure of Amines01:19

Structure of Amines

The hybridized nitrogen atom in amines possesses a lone pair of electrons and is bound to three substituents with a bond angle of around 108°, which is less than the tetrahedral angle of 109.5°. However, the C–N–H bond angle is slightly larger at 112°, with a carbon–nitrogen bond length of 147 pm. This carbon–nitrogen bond length of of amines is longer than the carbon–oxygen bond of alcohols (143 pm) but shorter than alkanes’ carbon–carbon bond (154 pm). These aspects are illustrated in Figure...
Basicity of Heterocyclic Aromatic Amines01:25

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).
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview01:07

Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview

In the presence of an aqueous base and a halogen, primary amides can lose the carbonyl (as carbon dioxide) and undergo rearrangement to form primary amines. This reaction, called the Hofmann rearrangement, can produce primary amines (aryl and alkyl) in high yields without contamination by secondary and tertiary amines.
Chirality at Nitrogen, Phosphorus, and Sulfur02:30

Chirality at Nitrogen, Phosphorus, and Sulfur

Chirality is most prevalent in carbon-based tetrahedral compounds, but this important facet of molecular symmetry extends to sp3-hybridized nitrogen, phosphorus and sulfur centers, including trivalent molecules with lone pairs. Here, the lone pair behaves as a functional group in addition to the other three substituents to form an analogous tetrahedral center that can be chiral.
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
Nomenclature of Aryl and Heterocyclic Amines01:10

Nomenclature of Aryl and Heterocyclic Amines

The simplest aromatic amine is phenylamine, which contains an –NH2 functionality directly attached to an aromatic ring. The name aniline is designated for this skeleton. As shown in Figure 1, the common names of the functionalized anilines involve prefixes ortho-, meta-, and para- to indicate the substitution position. Different functionalized aniline derivatives also have notable trivial names.
Aromatic Hydrocarbon Anions: Structural Overview01:18

Aromatic Hydrocarbon Anions: Structural Overview

Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous overlap of p...

You might also read

Related Articles

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

Sort by
Same author

Triple Pancake Bonding in Neutral π-Conjugated Dimers: a Computational Study.

Journal of the American Chemical Society·2026
Same author

Chemical Oxidation of Coronene: A Crystallographic and Computational Study of Charge-Regulated π‑Stacking.

ACS physical chemistry Au·2026
Same author

Designing Pancake-Bonded Heterodimers for Scanning Probe Microscopy.

The journal of physical chemistry. A·2026
Same author

Building a Mixed Polyarene π‑Stack with Charge Disparity through Chemical Oxidation: A Structural and Theoretical Investigation.

Precision chemistry·2025
Same author

The Effects of an Initial Extreme Drought and Chronic Change in Precipitation on Plant Biomass Allocation in a Temperate Grassland.

Ecology and evolution·2025
Same author

COLUMBUS─An Efficient and General Program Package for Ground and Excited State Computations Including Spin-Orbit Couplings and Dynamics.

The journal of physical chemistry. A·2025

Related Experiment Video

Updated: Jun 2, 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

Conformations of antipyrines.

Michael Roumanos1, Miklos Kertesz

  • 1Department of Chemistry, Georgetown University, Washington, DC 20057-1227, United States.

The Journal of Physical Chemistry. A
|April 16, 2011
PubMed
Summary

Density functional theory (DFT) combined with structural database analysis reliably predicts molecular crystal structures. This approach validates unusual conformations in antipyrine molecules, like propyphenazone, within their conformational landscape.

Area of Science:

  • Crystallography
  • Computational Chemistry
  • Medicinal Chemistry

Background:

  • Accurate conformational energetics are crucial for understanding and predicting molecular crystal structures.
  • Antipyrines are bioactive molecules where nitrogen pyramidalization influences substituent orientation and crystal packing.

Purpose of the Study:

  • To establish a combined density functional theory (DFT) and structural database approach for reliable conformational energetics in molecular crystals.
  • To investigate the conformational landscape of antipyrines, focusing on nitrogen pyramidalization and its effect on crystal structures, using propyphenazone as a case study.

Main Methods:

  • Utilized density functional theory (DFT) calculations to model conformational energetics.
  • Analyzed a large structural database (Cambridge Structural Database - CSD) of antipyrine conformations.

More Related Videos

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

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
11:45

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

Published on: August 22, 2018

Related Experiment Videos

Last Updated: Jun 2, 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

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

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
11:45

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

Published on: August 22, 2018

  • Examined the hysteretic property of phenyl torsion in propyphenazone.

    • Main Results:

    • The combined DFT-structural database approach provides a robust foundation for predicting crystal structures.
    • Observed that nitrogen pyramidalization significantly impacts substituent orientation, generally favoring opposite sides of the heteroaromatic ring.
    • Demonstrated that the seemingly sterically crowded propyphenazone conformation is consistent with the computed conformational map and CSD data, not an outlier.

    Conclusions:

    • The integrated computational and database methodology is effective for conformational analysis in molecular crystals.
    • The study validates the conformational flexibility of antipyrines and explains observed structural variations.
    • The findings contribute to a deeper understanding of structure-property relationships in bioactive molecules.