Formyl- and acetylindols: vibrational spectroscopy of an expectably pharmacologically active compound family.
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.
Billes
Ferenc
F
Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest, Budafoki út 8, Hungary. fbilles@mail.bme.hu
Podea
Paula Veronica
PV
Mohammed-Ziegler
Ildikó
I
Toşa
Monica
M
Mikosch
Hans
H
Irimie
Dan-Florin
DF
D003198:Computer Simulation; D007211:Indoles / Q000737:chemistry*; D008968:Molecular Conformation; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D014732:Vibration
C528934:3-formylindole; D007211:Indoles; C531932:3-acetylindole