Reactions of nickelocene with sodium in the presence of terminal alkenes

A novel reduction of nickelocene with metallic sodium in the presence of 1-pentene and 1-hexene was studied. It was found that two products of alkene activation were formed. The first one was a (μ3-hydrido)-(μ3-alkylidyne)-trinickel cluster (1) and the second one a (μ3-alkylidyne)-trinickel cluster (3). Both types of clusters were characterised by spectroscopic methods and by single-crystal X-ray diffraction measurements. The first cluster crystallised from hexane in a monoclinic system in the C2/c space group and the second one from methanol, also as a monoclinic system in the P21/c space group.