REACTIVITY OF TETRAMETHYLDISILANDIYL BIS( 3-TRIMETHYLSILYLCYCLOPENTADIENYL)-TETRACARBONYL DIIRON

The Fe-Fe bond of the title compound (Me(2)SiSiMe(2))[eta(5)-(3-Me(2)S iC(5)H(3))Fe (CO)](2)(mu-CO)(2)(A) was cleaved by sodium amalgam and t he corresponding bis(iron anion) produced. The nucleophilic reaction o f the anion with MeCOCl, PhCOCl, PhCH(2)Cl, ClCH2COOC2H5 and Ph(3)SnCl gave respectively the alkylation, acylation and metallation products iSiMe(2))[eta(5)-(3-Me(3)SiC(5)H(3))Fe(CO)(2)R](2) (R: CH3CO (1), PhCO (2), PhCH(2) (3), CH2COOC2H5 (4), Ph(3)Sn (5)). The Fe-Fe bond was al so cleaved by iodine in chloroform and resulted in forming iron iodide (Me(2)SiSiMe(2)) [eta(5)-(3-Me(3)SiC(5)H(3))Fe(CO)(2)I](2) (6). Howev er the reaction of A with iodine in benzene yielded Fe-I+-Fe bridged i onic compound (Me(2)SiSiMe(2)) [eta(5)-(3-Me(3)SiC(5)H(3))Fe(CO)(2)]I- 2(+). I-3(-) (7). The crystal structure of 6 was deter3 mined by X-ray diffraction. The crystal is monoclinic, space group P2(1)/c with a=1. 7217(4) nm, b=0.7753(2) nm, c=1.3629(7) nm, beta=103.80(1)degrees, V=1 .767(2) nm(3), 2=4, D-c= 1.629 g/cm(3). The final deviation factor R=0 .054.