Croatica Chemica Acta, Vol. 89 No. 1, 2016.
Izvorni znanstveni članak
https://doi.org/10.5562/cca2881
Supramolecular Influence on Keto-Enol Tautomerism and Thermochromic Properties of o-Hydroxy Schiff Bases
Marija Zbačnik
orcid.org/0000-0001-8747-410X
; Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia
Branko Kaitner
; Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia
Sažetak
This work presents a study on thermo-optical properties of three Schiff bases (imines) in the solid state. The Schiff bases were obtained by means of mechanochemical synthesis using monosubstituted o-hydroxy aromatic aldehydes and monosubstituted aromatic amines. The keto-enol tautomerism and proton transfer via intramolecular O∙∙∙N hydrogen bond of the reported compounds was found to be influenced more by supramolecular interactions than by a temperature change. All products were characterised by powder X-ray diffraction (PXRD), FT-IR spectroscopy, thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). Molecular and crystal structures of compounds 1, 2 and 3 were determined by single crystal X-ray diffraction (SCXRD). The molecules of 1 appear to be present as the enol-imine, the molecules of 2 as the keto-amine tautomer and the molecules of 3 exhibit keto-enol tautomeric equilibrium in the solid state. An analysis of Cambridge structural database (CSD) data on similar imines has been used for structural comparison.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Ključne riječi
keto-enol tautomerism; Schiff bases; mechanochemistry; thermochromism
Hrčak ID:
159501
URI
Datum izdavanja:
20.6.2016.
Posjeta: 2.281 *