Naslov
Vibrational analysis of selected nicotinic acid hydrazones in solid state

Autori
Miljanić, Snežana ; Kenđel, Adriana ; Domokos, Reka ; Chiş, Vasile ; Kontrec, Darko ; Galić, Nives

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
EUCMOS 2016 Programme & Book of Abstracts / - Budimpešta : Hungarian Chemical Society, 2016, 162-162

ISBN
978-963-9970-68-7

Skup
33rd European Congress on Molecular Spectroscopy

Mjesto i datum
Szeged, Mađarska, 30.07.2016. - 04.08.2016

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
aroylhydrazones ; vibrational spectra ; tautomer ; isomer

Sažetak
Aroylhydrazones exist in various tautomeric and isomeric forms, depending on their molecular structure and the presence of other species, such as solvent or a metal ion. Particularly interesting are those with a hydroxyl group in ortho position regarding the C=N double bond, which can be involved in tautomeric equilibria not only with the hydrazide part of the molecule, adopting a ketoamine form (form I, –CO–NH–N=CH–) or an enolimine form (form II, –COH=N–N=CH–), but also with the salicylaldehyde originating part of the molecule, yielding in a form with a carbonyl group on the cyclic moiety (form III, –CO–NH–NH–CH=CH–CO–). Five new aroylhydrazones derived from nicotinic acid were synthesized, all having an ortho hydroxyl group, but differing in the other substituent and its position on the aromatic ring (Fig. 1). Hence structural forms of derivatives with an additional hydroxyl group in position 3 (1) and 5 (2), chlorine atom in position 3 (3), a methoxy group in position 4 (4) and a nitro group in position 5 (5) on the phenyl ring were studied using vibrational spectroscopy. Infrared (IR) and Raman spectra of the solid substances were acquired and the normal modes assigned using DFT calculations at B3LYP/6-31+G(2d, 2p) level of theory, within both, harmonic and anharmonic approximations. The optimized geometries as well as IR and Raman spectra were obtained for four tautomeric (I–IV) and two isomeric (E and Z) forms for each of the synthesized compounds. The theoretical results indicated that the dominant structure of all the studied aroylhydrazones was the most stable E isomer in ketoamine form I. Moreover, characteristic IR and Raman bands were identified for all the investigated compounds.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA