Sensitive and Selective Chromogenic Sensing of Carbon Monoxide by Using Binuclear Rhodium Complexes

CO-catcher: Carbon monoxide can be detected selectively and sensitively by the binuclear rhodium complex cis-[Rh2(C6H4PPh2)2(O2CCH3)2](HO2CCH3)2. This complex, which contains two cyclometalated phosphine ligands, coordinates CO axially and undergoes a color change from violet to orange-yellow (see picture).