Related Experiment Video
Updated: Jun 19, 2026

Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine
Published on: June 13, 2022
Formyl- and acetylindols: vibrational spectroscopy of an expectably pharmacologically active compound family
Ferenc Billes1, Paula Veronica Podea, Ildikó Mohammed-Ziegler
1Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest, Budafoki út 8, Hungary. fbilles@mail.bme.hu
Abstract:
In the present paper, indole and its seven derivatives were compared, namely 3-formylindole, 1-methyl-3-formylindole, 1-ethyl-3-formylindole, 3-acetylindole, 1-methyl-3-acetylindole, 1-ethyl-3-acetylindole and 1,3-diacetylindole. The substitution of indole in position 3 with aldehydes and with alkyl groups cause only minor changes in the molecular geometry, however, substantially larger alterations are found in the charge distribution and in the vibrational force constants. The appearance of the aldehyde groups increased the degree of association as it was observable on the shape of infrared NH stretching band and its shifts. The alkyl substitution shifts the aldehyde carbonyl stretch band frequencies to somewhat higher values. The effect of the second acetyl group in position 1 is not comparable with those of the 1-alkyl groups. The latter effect is observable in the molecular geometry, however, it is more pronounced in the changes of the net charge distribution, the vibrational force constants and the infrared spectra.
Related Concept Videos
Spectroscopy of Carboxylic Acid Derivatives
In the...
¹H NMR Signal Integration: Overview
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
Infrared (IR) Spectroscopy: Overview
Different compounds display unique properties due to their...
IR Frequency Region: Fingerprint Region
The...

