In contrast to the high reactivity of such freshly produced metal atoms, bulk metals typically are unreactive toward neutral ligands.
The technique relies on a reactor that evaporates the metal, allowing the vapor to impinge on a cold reactor wall that is coated with the organic ligand.
The metal evaporates upon being heated resistively or irradiated with an electron beam.
[1] In a common implementation, the metal vapor and the organic ligand are co-condensed at liquid nitrogen temperatures.
Thus, tris(butadiene)molybdenum was first prepared by co-condensation of butadiene and Mo vapor, but yields are higher for the reduction of molybdenum(V) chloride in the presence of the diene.