ABSTRACT
The Schiff base (HLBr), containing a chelating unit and triphenylphosphonium moiety has been synthesized in the reaction of 4-aminobenzyl(triphenyl)phosphonium bromide with 5-hydroxy-3-methyl-1-phenyl-4-formylpyrazole. The composition and structure of HLBr have been determined by elemental analysis, IR, 1D and 2D NMR, electronic spectroscopy and mass spectrometry. Density functional theory (DFT) calculations (6-311G(d,p) level of theory) have been carried out to investigate tautomeric forms of HL+ and the reaction mechanism of its formation and spectral properties. The most stable form in the solid state and in DMSO solution is pyrazolone (keto-amine) tautomeric form.
GRAPHICAL ABSTRACT
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Acknowledgments
This work was supported by the RA MES SCS, within the frames of the «RA MES SCS – YSU-RF SFEDU» joint project No. VnGr-07/2017–35, Ministry of Education, Science and Technological development of the Republic of Serbia (Grant OI 172055) and taking advantage of the facilities of Resource Centers of SFEDU (“Molecular spectroscopy”, “High-productive calculations” and “Nanoscale structure of matter”).