Related Experiment Video
Updated: Apr 26, 2026

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines
Published on: June 23, 2019
Microwave spectrum and conformational composition of (azidomethyl)cyclopropane (C3H5CH2N3)
Harald Møllendal1, Svein Samdal, Jean-Claude Guillemin
1Centre for Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo , Blindern, NO-0315 Oslo, Norway.
Abstract:
The microwave spectrum of (azidomethyl)cyclopropane, C3H5CH2N3, has been investigated in the 26-90 GHz spectral range at a temperature of about -30 °C. Five rotameric forms of this compound, whose spectra can be distinguished by microwave spectroscopy, may exist. The spectra of three of them denoted III, IV, and V were assigned. The ground vibrational state spectra of III and V were assigned, while the ground and six vibrationally excited states were assigned for IV. These three rotamers all have a synclinal orientation of the H-C-C-N chain of atoms, while the C-C-N-N link is either + or - synclinal or antiperiplanar. Conformer IV, having synclinal orientation of the two said dihedral angles, was found to have the lowest energy by relative intensity measurements. Rotamer V has an energy that is 1.6(6) kJ/mol higher than the energy of IV, while the energy of III is 2.1(6) kJ/mol higher than the energy of IV. Quantum chemical calculations were performed at the MP2/cc-pVTZ and CCSD/cc-pVTZ levels of theory. The rotational constants obtained in the CCSD calculations are in good agreement with the experimental rotational constants, while the MP2 centrifugal distortion constants are generally in poorer agreement with their experimental counterparts.
More Related Videos
11:45Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
09:35Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Conformations of Cycloalkanes
Mass Spectrometry: Cycloalkane Fragmentation
For example, cyclohexane molecular ions have a mass-to-charge ratio (m/z) of 84, which tends to produce a stronger signal than linear alkanes like hexane. This stability comes from...
Chair Conformation of Cyclohexane
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
Conformations of Cyclohexane
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...