Illuminating Metal-Ion Sensors: Benzimidazolesulfonamide Metal Complexes

The synthesis, structure, and solution spectroscopy of several (2-sulfonamidophenyl)benzimidazole metal complexes are reported. These ligands, which have been reported as selective molecular sensors for Zn2+, readily form complexes with Co2+, Ni2+, Cu2+, and Zn2+. Surprisingly, the ligand adopts different binding modes depending on the metal ion. The work here provides insight into the coordination chemistry of these ligands, which may allow for the development of improved metal-ion sensors and metalloprotein inhibitors.