Co(III) complexes have been proposed as low cost prodrugs in chemotherapeutics with potentially favorable and tunable properties. However, the use of octahedral, low-spin Co(III) complexes with only monodentate ligands as prodrugs remains a relatively unexplored area in cancer research. Utilizing the known complex, trans-dichlorotetrakis(pyridine)cobalt(III) chloride, under reflux conditions in the presence of excess 5-methyl-1H-indazole, a new coordination complex was reproducibly obtained via ligand exchange albeit in low yields. 1H and 13C NMR studies allowed for structural elucidation of a new complex with partial substitution of the pyridine ligands. Interestingly, the two 5-methyl-1H-indazole ligands appear to bind to the octahedral cobalt(III) metal center through a deprotonated carbon atom in the third position of the indazole ring. Addition of either strong or weak bases prior to reflux conditions did not result in any significant increase in product yields. Work continues in order to optimize the reaction conditions to produce high yields of a new Co(III) coordination complex with 5-methyl-1H-indazol-3-yl ligands. Future studies will focus on the full structural characterization and biological relevance of this new complex for potential medicinal applications.

Progress toward the synthesis of a new cobalt(III) coordination complex with 5-methyl-1H-indazole ligands

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.