[Re(η 6 ‐C 6 H 5 ‐benzimidazole) 2 ] + and Derivatives as Dye Mimics; Synthesis, UV Absorption Studies and DFT Calculations

Functionalizations of highly oxidation and hydrolysis stable mono-cationic rhenium bis-arene complexes [Re(η6-C6H6)2]+ are great interest. We directly built up structural features the well-known Hoechst Dye on coordinated arenes as a model for prospective DNA minor groove binding studies. Extensions aromatic unit with functionalized derivatized benzimidazole moieties resulted in deep orange colour complexes, showing UV/Vis absorption spectra multiple transition maxima. These have been assigned support DFT calculations to gain information about their charge transfer natures. The different transitions which either intra-ligand, ligand-to-ligand or metal-to-ligand transitions, were additionally compared discussed corresponding free ligands.