Thermolysis of Ru3(CO)12 with 1,3-ynone ligand flourished five new Ru2–Ru4 clusters.
The rare example of the fluxional capped 1,3-ynone ligand was observed in the crystal structure of 3.
The formation of 1,3-ynone capped ruthenium clusters required a precise control on the reaction conditions.
The mechanistically relevant cluster intermediates were stabilized by robust 1,3-ynone ligand.