Naslov
Structural investigation of aroylhydrazones derived from nicotinic acid hydrazide in solid state and in solution

Autori
Brođanac, Ivan ; Kontrec, Darko ; Miljanić, Snežana ; Galić, Nives

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

Izvornik
Knjiga sažetaka 23. Hrvatskog skupa kemičara i kemijskih inženjera / Hadžiev, Andrea ; Blažeković, Zdenko - Zagreb : Hrvatsko društvo kemijskih inženjera i tehnologa (HDKI), 2013, 94-94

ISBN
978-953-6894-50-5

Skup
23. Hrvatski skup kemičara i kemijskih inženjera

Mjesto i datum
Osijek, Hrvatska, 21.04.2013. - 24.04.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
Aroylhydrazones ; Tautomerism ; Isomerisation ; Spectroscopy

Sažetak
Structural forms of aroylhydrazones derived from nicotinic acid hydrazide have been studied in the solid state by FT-IR spectroscopy and in solution by NMR, UV-Vis and ATR spectroscopy. The studied compounds were N'-benzylidene-3-pyridinecarbohydrazide (1), N'-(2, 4-dihydroxyphenylmethylidene)-3-pyridinecarbohydrazide (2), N'-(5-chloro-2-hydroxyphenylmethylidene)-3-pyridinecarbohydrazide (3), and N'-(3, 5-dichloro-2-hydroxymethoxyphenylmethylidene)-3-pyridinecarbohydrazide (4). The compound 1 adopted the most stable ketoamine form (form I, –CO–NH–N=C–) in the solid state as well as in various organic solvents. In mixtures of organic solvents with water the UV-Vis and ATR spectra implied intermolecular hydrogen bonding of 1 with water molecules. The presence of both tautomeric forms I and II (form II, –COH=N¬–N=C–) was proposed for the solid substance and highly concentrated solutions of 2, whereas form I was detected as the predominant one in diluted solutions. For compounds 3 and 4 a coexistence of forms I and III (form III, –CO–NH–NH–C=C–CO–) was noticed in the solid state and in polar protic organic solvents. The conversion to form III was induced by increasing the water content in the solvent mixtures. This process was the most pronounced for compound 4. When exposed to daylight, an appearance of a new band was observed during time in the UV-Vis spectrum of 4 in organic solvent/water 1/1 mixtures which implied that tautomeric interconversion was most likely followed by E/Z isomerisation.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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