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

Acid Halides to Amides: Aminolysis

Acid Halides to Amides: Aminolysis

Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...

Structure of Amines

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 Aliphatic Amines

Basicity of Aliphatic Amines

Amines can behave as Brønsted–Lowry bases by accepting a proton from the acid to form corresponding conjugate acids. Due to a lone pair of nonbonding electrons, aliphatic amines can also act as Lewis bases by forming a covalent bond with an electrophile.
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates higher...

Preparation of 1° Amines: Hofmann and Curtius Rearrangement Mechanism

Preparation of 1° Amines: Hofmann and Curtius Rearrangement Mechanism

The Hofmann and Curtius rearrangement reactions can be applied to synthesize primary amines from carboxylic acid derivatives such as amides and acyl azides. In the Hofmann rearrangement, a primary amide undergoes deprotonation in the presence of a base, followed by halogenation to generate an N-haloamide. A second proton abstraction produces a stabilized anionic species, which rearranges to an isocyanate intermediate via an alkyl group migration from the carbonyl carbon to the neighboring...

NMR Spectroscopy Of Amines

NMR Spectroscopy Of Amines

In proton NMR spectroscopy, primary amines and secondary amines showcase their N–H protons as a broad signal in the chemical shift range between δ 0.5 and 5 ppm. The exact position in this range depends on several factors, including sample concentration, hydrogen bonding, and the type of solvent used. Since amine protons undergo fast proton exchange in solution, the protons are labile and therefore do not participate in any splitting with adjacent protons. Thus, the observed peak is broad and...

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

Accurate Sizing and Resolution of Nominal 200 nm Diameter Polystyrene Nanospheres With Charge Detection Mass Spectrometry.

Small (Weinheim an der Bergstrasse, Germany)·2026

Same author

Atmospheric Sampling Mass Spectrometers Activate and Ionize Neutral Water Microdroplets to MeV Energies and up to 200,000+ Charges: Implications for Water Stability and Unusual Chemistry in Microdroplets.

ACS central science·2025

Same author

Response to Comment on "An Alternative Explanation for Ions Put Forth as Evidence for Abundant Hydroxyl Radicals Formed Due to the Intrinsic Electric Field at the Surface of Water Droplets".

Analytical chemistry·2025

Same author

Adeno-associated virus serotype 9 structural heterogeneity and stability characterized by charge detection mass spectrometry.

Molecular therapy. Methods & clinical development·2025

Same author

Effects of additives on the rheology and phase behavior of lamellar-structured concentrated surfactant solutions.

Soft matter·2025

Same author

An Alternative Explanation for Ions Put Forth as Evidence for Abundant Hydroxyl Radicals Formed Due to the Intrinsic Electric Field at the Surface of Water Droplets.

Analytical chemistry·2025

Search research articles

Related Experiment Video

Updated: May 8, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Published on: February 15, 2016

Locating protonated amines in clathrates.

Terrence M Chang¹, Richard J Cooper, Evan R Williams

¹Department of Chemistry, University of California , Berkeley, California 94720-1460, United States.

Journal of the American Chemical Society

|September 7, 2013

Summary

Stable structures of hydrated protonated ammonia and amines with 20 water molecules were identified using spectroscopy. These magic number clusters exhibit clathrate-like structures, with ion location influencing stability and hydrogen bonding.

More Related Videos

Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations

Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations

Published on: April 26, 2024

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

Related Experiment Videos

Last Updated: May 8, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates

Published on: February 15, 2016

Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations

Synthesizing Amino Acids Modified with Reactive Carbonyls in Silico to Assess Structural Effects Using Molecular Dynamics Simulations

Published on: April 26, 2024

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

Area of Science:

Physical Chemistry
Chemical Physics
Spectroscopy

Background:

Investigating the influence of ions on water's hydrogen-bonding network is crucial.
Understanding the structures of hydrated ions provides insights into solvation and surface activity.

Purpose of the Study:

To determine the structures and stabilities of hydrated protonated ammonia and various amines.
To elucidate the role of ion type and water cluster size on structural formation.

Main Methods:

Infrared photodissociation (IRPD) spectroscopy.
Blackbody infrared radiative dissociation (BIRD) spectroscopy at 133 K.
Comparison with reference ions (Rb+, protonated tert-butylamine).

Main Results:

Magic number clusters (MNCs) with 20 water molecules were observed for most ions, indicating stable clathrate-like structures.
Tetramethylammonium and smaller/larger clusters showed non-clathrate structures.
Protonated ammonia was found in the interior, while protonated methyl- and n-heptylamine were at the surface of the clathrate.

Conclusions:

The number and orientation of hydrogen bonds, not just the quantity, dictate cluster stability.
Experimental findings serve as benchmarks for computational studies on ion-water interactions.