Related Experiment Video
Updated: May 19, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Carbonyl diazide, OC(N3)2: synthesis, purification, and IR spectrum
Alex M Nolan1, Brent K Amberger, Brian J Esselman
1Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706-1322, USA.
Abstract:
Carbonyl diazide (1), OC(N(3))(2), is prepared by reaction of triphosgene and tetra-n-butylammonium azide in a solution of diethyl ether or dimethyl ether. The advantage of this synthetic method, relative to other procedures, is that the use of triphosgene, OC(OCCl(3))(2), mitigates the need to use highly poisonous reagents such as phosgene, OCCl(2), or chlorofluorocarbonyl, OC(Cl)F. The identity and purity of OC(N(3))(2) are established by gas-phase IR spectroscopy, which reveals the presence of both syn-syn and anti-syn conformers. Computed anharmonic vibrational frequencies and infrared intensities of carbonyl diazide (1) display excellent agreement with experiment, and reveal the presence of strong Fermi resonances.
Related Concept Videos
Carboxylic Acids to Methylesters: Alkylation using Diazomethane
Preparation of Amides
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
Spectroscopy of Carboxylic Acid Derivatives
In the...
Preparation of Nitriles
IR and UV–Vis Spectroscopy of Carboxylic Acids
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency, 1710 cm−1. The C=O bond of the...
IR and UV–Vis Spectroscopy of Aldehydes and Ketones

