Carbon monoxide(CO)is a poisonous gas.But like NO,it has important physiological roles to play.Metallocarbonyl complexes decompose under appropriate conditions to release CO and therefore,represent a promising class of future pharmaceuticals as CO-releasing molecules(CORMs)[1-3].Among the reported methods for triggering CO-release,photo-activation is particularly favored due to its easy controllability of timing and location.For photoCORMs,longer wavelength visible/near-infrared(NIR)light are needed to activate the CO release owing to the potentially harmful of short wavelength light.One of the strategies is to use heterogenic binuclear metal complexes.These complexes exhibit additional metal-metal-bond to ligand charge transfer band(MMLCT),which can absorb longer wavelength photons to result in long wavelength absorbance.In this work,two new binuclear rhenium-manganese complexes(CO)5ReMn(CO)3L were synthesized with aldehyde or carboxylic group in 1,10-phenanthroline ligand.As expected,such binuclear complexes can exhibit broad MMLCT band centered at much longer wavelength(~600 nm).In both aerobic and anaerobic solution,these binuclear rhenium-manganese complexes can release CO under LED excitation at 659 nm.Quantum yields under different conditions were calculated.GC-TCD was also used to measure the CO released from these complexes,which shows CO can be released from these complexes under the excitation of long wavelength at 659 nm.So this type of binuclear complex can be good candidate serving as photoCORMs.