METAL CLUSTERS IN CATALYSIS. THE REACTIVITY OF ALKYNE- AND VINYLIDENE-SUBSTITUTED HOMO- AND HETERO-METALLIC CLUSTERS TOWARDS MOLECULAR HYDROGEN IN HOMOGENEOUS CONDITIONS

Article abstract of DOI:10.1016/S0022-328X(00)99260-X

The reactivity of alkyne- and vinylidene-substituted clusters towards molecular hydrogen in homogeneous conditions has been studied by means of GC and GC/MS techniques.The reactivity of the homo- and hetero-metallic cluster frames (containing nickel and one of the iron triad metals) is discussed, as well as that of the coordinated ligands.Under hydrogen the cluster cores are modified, sometimes as a part of a catalytic cycle.The products obtainable from the coordinated small molecules seem to depend mainly on the overall electronic situation of the clusters or on the C-C distances in the alkynes, and to a lesser extent on the number of coordinating metal centres.In some instances it was observed that when both free alkynes and substituted clusters were present, only the coordinated alkynes were hydrogenated.