Infrared study of triruthenium dodecacarbonyl interactions with gold

► Adsorption of Ru3(CO)12 is molecular and reversible on the Au(111) surface at 200 K. ► The Ru3 molecular plane is parallel to the surface in the first two layers. ► The undissociated molecules desorb above 275 K. ► On high-index surfaces a fraction of carbonyl dissociates and forms CO-covered Ru-islands.