Clusters containing edge-bridging N-donor ligands

4 Clusters containing edge-bridging N-donor ligands 

The edge-bridged carbonyl cluster compound [Ru3( -H)(//-dmdab)(CO)9] (36) (Hdmdab = 3,5-dimethyl-l,2-diaminobenzene) (Fig. has proved to be an ex- 

Although it is not possible to propose a mechanism for the catalytic hydrogenation reaction promoted by complex 36, the following data suggest that the catalyst is a mononuclear species (a) 36 does not react with hydrogen but reacts with diphenylacetylene to give a catalytically inactive binuclear compound (37) and a presumably mononuclear species and (b) the catalytic reaction is first-order in the concentration of 36 added, and this concentration should be equal to that of the mononuclear species which arises from the quantitative reaction of 36 with diphenylacetylene. 

These results raise doubts about the possible intermediacy of polynuclear catalytic species when edge-bridged trinuclear carbonyl cluster complexes are used as catalyst precursors. 

---

S.2.4 Clusters containing edge-bridging N-donor ligands... 

---