A rhenium (I) bipyridine complex Re (CO) 3 (bipy) (py‐Rho) (PF 6) 2 coordinated with a rhodamine‐decorated monodentate ligand (py‐Rho +) was designed and synthesized. Compared to the free ligand, the characteristic rhodamine absorption and emission in such rhodamine‐rhenium (I) complex are redshifted, indicative of direct electronic communication between rhodamine and rhenium (I) units. Interesting decolorization reaction with cyanide ion, with decolorization and diminishment of rhodamine absorption and emission bands, was observed. The decolorization is ascribed to the nucleophilic attack from cyanide ion to the carbon atom at the 9 position of rhodamine with increased electrophilicity upon the coordination rhenium (I) moiety.
Liang et al. (Wed,) studied this question.