These compounds have shown potential in cluster capping
reactions.
Photolysis of Ru(CO)4(C2H4) in the
donor solvent acetonitrile leads to the highly reactive novel mononuclear
compound Ru(CO)3(C2H4)(MeCN).
Vibrational analysis points towards a di-axial arrangement of the olefin and
acetonitrile ligands.

This is the first reported example of a mononuclear ruthenium
complex containing an olefin in an axial position.