Original scientific paper

A Discussion of the Absorption Spectra of Substituted 4-Pyridones and Their 4-Thio Analogues

K. Blažević ; Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia
N. Trinajstić ; Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia

Abstract

The absorption spectra of 3-hydroxy-1-aryl-4-pyridones, 2-carbethoxy-
5-hydroxy-1-aryl-4-pyridones and their 4-thio analogues are
reported . The thio compounds exhibit a red shift in the characteristic
long wavelength maximum, which can be explained with the help
of the inductive effect when oxygen is replaced by sulphur. Similarly,
with the help of the first-order inductive effect, a red shift
in the bands is discussed . This shift is produced by the substitution
of a carbethoxy group at position 2 of the pyridone ring (the charge
distributions in the ring are calculated from Hilckel molecular
orbitals). Finally, a red shift produced by substitution onto the
nitrogen in the ring is examined with the help of the mesomeric
effect.

Keywords

Hrčak ID:

208104

URI

https://hrcak.srce.hr/208104

Publication date:

25.4.1967.

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