Oxorhenium(V) complexes composed of beta-emitting Re-186 and Re-188 isotopes are of current interest in radiopharmaceutical medicine. Rhenium complexes of 1,2,3-trihydroxybenzene were prepared by reactions of a Re(V) precursor (tetrabutylammonium tetrachlorooxorhenate) with twofold molar excess of the ligand in acetonitrile.
The structural formulae of the complexes and their consequent reaction products, as well as those of the final reaction products bis(1,2,3-trihydroxybenzene)-dioxorhenium(VII) and 1,2,3-trihydroxybenzene-chloro-dioxorhenium(VII), synthesized in two different reactions differing in the amount of triethylamine added to the reaction mixture, were estimated by means of physicochemical and spectroscopic methods. ESI-MS spectra in negative mode were also obtained.
The reactions during the course of complex formation and consequent decomposition were primarily followed by ESI-MS, and time-dependent ESI-MS signals were recorded and compared to those obtained by UV/Vis absorption spectroscopy.