title: Synthesis, NMR structural characterization and molecular modeling of substituted thiosemicarbazones and semicarbazones using DFT calculations to prove the syn/anti isomer formation.
abstract: Thiosemicarbazones possessing electron-donating and electron-withdrawing groups were prepared, and their spectral characteristics determined. In all cases, the spectra showed that one isomer was formed, allowing further functionalization to molecules of biological interest. We provide NMR data for some of the thiosemicarbazones and semicarbazones. We also provide evidence that for 2-pyridyl thiosemicarbazone, the syn isomer slowly converts into the anti isomer in dimethyl sulfoxide solvent with first-order kinetics. Molecular modeling and density functional theory calculations confirmed these observations.
authors.affiliation: Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia, 4072.
authors.forename: T K
authors.initials: TK
authors.lastname: Venkatachalam
authors.forename: Gregory K
authors.initials: GK
authors.lastname: Pierens
authors.forename: David C
authors.initials: DC
authors.lastname: Reutens
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D008958:Models, Molecular; D015394:Molecular Structure; D011789:Quantum Theory; D012015:Reference Standards; D012664:Semicarbazones / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism; D013882:Thiosemicarbazones / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D012664:Semicarbazones; D013882:Thiosemicarbazones
keywords: DFT calculations; semicarboazones; structure elucidation; synthetic methods; thiosemicarbazones