Novel polychlorinated metallocenes are provided that have the following formulas: C5H5-mClmMC5H5 and (C5H5-nCln)2M, wherein M is iron, ruthenium or osmium, m is an integer from 3 to 5, inclusive, and n is an integer from 2 to 5, inclusive. The products are prepared by (1) reacting a monochlorometallocene or a 1,1'-dichlorometallocene with an organolithium compound in the presence of a solvent, (2) recovering a 1-chloro-2-lithiometallocene or a 1,1'-dichloro-2,2'-dilithiometallocene depending upon the starting material used, and (3) then reacting one of the latter compounds with a chlorination agent to obtain 1,2-dichlorometallocene or 1,1',2,2'-tetrachlorometallocene. The lithiation step and the chlorination step can then be repeated one, two, 3 or more times, using in each reaction as the starting material the isolated chlorinated product from the prior reaction. The polychlorinated metallocenes are useful in preparing metallocene-containing polymers that are particularly suitable as ablative plastics for heat shields and structural laminates for light weight radiation shields. They also can be used to synthesize high temperature and/or high density fluids as well as for additives for lubricants and as flame retardant additives. The decachlorometallocenes are particularly useful because of their high resistance to oxidation.