Reactions of di-mu-carbonyl-cis-mu-(1-5-eta : 1 '-5 '-eta-dicyclopentadienyl-dimenthylsilane) bis(carbonyliron) with aryllithium reagents. Crystal structures of [Fe-2(mu-CO){mu-C(OC2H5)C6H5)(CO)(2){(eta(5)-C5H4)(2)Si(CH3)(2)}] and [Fe-2(mu-CO){mu-C(OC2H5)C6H4OCH3-p}(CO)(2){(eta(5)-C5H4)(2)Si(CH3)(2)}]

The reactions of di-mu -carbonyl-cis-mu-(1-5-eta :1'-5'-eta -dicyclopentadi enyl-dimethyl silane)bis(carbonyliron), [Fe-2(mu -CO)(2)(CO)(2)(CO)(2){(eta (5)-C5H4)(2)Si(CH3)(2)}] (1), with aryllithium reagents, ArLi (Ar = C6H5, o-, m-, p-CH3C6H4, p-CH3OC6H4, p-ClC6H4, p-CF3C6H4), in ether at low temper ature afforded acylmetalate intermediates, followed by alkylation with Et3O BF4 in aqueous solution at 0 degreesC or in CH2Cl2 at -30 degreesC gave the (dicyclopentadienyldimethylsilane)diiron bridging alkoxycarbene complexes [Fe-2(mu -CO){mu -C(OC2H5)Ar}(CO)(2){(eta (5)-C5H4)(2)Si(CH3)(2)}] (2, Ar = C6H5; 3, Ar = o-CH3C6H4; 4, Ar = m-CH3C6H4; 5, Ar = p-CH3C6H4; 6, Ar = p-C H3OC6H4; 7, Ar = p-ClC6H4; 8, Ar = p-CF3C6H4), among which the structures o f 2 and 6 have been established by X-ray diffraction studies. (C) 2001 Else vier Science B.V. All rights reserved.