IR spectroscopic and DFT investigations on molecular conformations of thio-free oxo technetium (V) benzamidoxime complexes

Synthesized 99m/99gTc complex with benzohydroxamamide (BHam), 99m/99gTc/BHam2 characterized with HPLC equipped with UV–Vis and ESI–MS, and FTIR spectroscopic measurements were carried out. The structures of BHam conformers its complexes with Tc(V) (Tc/BHam2) computed using the density functional theory (DFT) calculations were obtained. Six conformers of Tc/BHam2 complexes based on the imino-, amino- and hydroxo-BHam tautomers as cis- and trans-conformers were found. The computed IR spectra of all the conformers of Tc/BHam2 complex were analyzed and compared with experimental spectrum. The IR spectrum of the trans-Tc/amino-BHam2 which is the most stable conformer is in good agreement with the measured spectrum.