engleski

STRUCTURAL ANALYSIS OF 2-METHOXYBEZALDEHYDE THIOSEMICARBAZONE DERIVATIVES : A COMBINED EXPERIMENTAL AND THEORETICAL STUDY

Thiosemicarbazones and their corresponding metal complexes are widely known compounds possessing diverse pharmacological activities. Bioactivity is closely related to molecular conformation which can significantly be affected by the presence of intra- and inter-molecular hydrogen bonds. Salicylaldehyde thiosemicarbazones can exist in several tautomeric forms with both intra- and inter-molecular hydrogen bonds. The aim of this research is to investigate the influence of substituents and solvents of different polarities on molecular conformation, tautomerism and structure of H-bonds in salicylaldehyde thiosemicarbazone derivatives. We present here a part of our study regarding the effect of substituting OH with OMe group in salycilaldehyde residue on the overall structure and thione-thiol tautomerism. Solid state structures were characterized by single-crystal X-ray diffraction and high resolution 13C and 15N solid-state NMR spectroscopy. Solid state NMR parameters (15N, 13C) were used as a reference for solution study results. Possible solvent induced conformational and tautomeric equilibrium changes were probed by multinuclear (1H, 13C and 15N) temperature dependent NMR experiments in CDCl3 and DMSO solutions and quantum- mechanical calculations.

thiosemicarbazones; NMR; hydrogen bonds; AIM analysis

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