The reduction of chromium(III) chloride with sodium indenyl leads init
ially to chromium (II) chloride, which then gives the dimeric compound
s (indenyl)(3)Cr2Cl (1) and (indenyl)(4)Cr-2 (2), both of which have b
een shown to contain mu-eta(3)-indenyl groups. 2 is catalytically acti
ve for the polymerization of ethylene and the hydrogenation of styrene
to ethylbenzene.