The reaction of the title compound (Me~2SiSiMe~2)[η^5-(C~5Me~4)Fe(CO)~2]~2(μ-CO)~2 (1) with iodine in benzene yielded the iodo-bridged complex (Me~2SiSiMe~2)[η^5-(C~5Me~4)Fe-(CO~2)]~2I^+·I~n^-(n=3, 3; n=5, 4). If the reaction was proceeded in chloroform, only the Fe-Fe bond cleaved iron iodide (Me~2SiSiMe~2)[η^5-(C~5Me~4)Fe(CO~2)~2I]~2 (2) was isolated. When 4 was dissolved in Me~2SO-Me~2CO, the two parts of I~5^- and Fe-I^+-Fe reacted each other to form the iodo-bridge cleaved product 2. The structures of 2-4 were characterized by elemental analysis, IR and ^1H NMR spectra. The crystal structure of 2 was determined by X-ray crystallography. The crystal is monoclinic, space group P 2~1/n, with a= 0.7656(2), b=1.6068(4), c=1.3030(6)nm; β=95.11(3)^0, V=1.597(2)nm^3, Z=2, D~c=1.735g·cm^-^3, μ=29.24cm^-^1, F(000)=820. The final deviation factor R is 0.037.

Key words: CRYSTAL STRUCTURE DETERMINATION, IODIDE, CARBONYL COMPOUNDS, IRON COMPOUNDS, IODINE, CYCLOPENTADIENYL GROUP