The synthesis and properties of [Fe 3(CO) 11(RCN)] derivatives, and a high-yield general route to mono- and di-substituted derivatives of [Fe 3(CO) 12]; the crystal and molecular structure of [Fe 3(CO) 11(NCC 6H 4-2-Me)

Abstract

The clusters [Fe 3(CO) 11(RCN)] ( 1: R = Me, C 3H 5, C 6H 5, or C 6H 4-2-Me) have been prepared at low temperature from [Fe 3(CO) 12] and RCN in the presence of Me 3NO. Compounds 1 react essentially quantitatively with a wide range of two-electron donors, L, (viz.: CO, PPh 3, P(OMe) 3, PPh 2H, PPh 2Me, PF 3, CyNC (Cy = cyclohexyl), P(OEt) 3, SbPh 3, PBu 3, AsPh 3, or SnR 2 (R = CH(SiMe 3) 2)) to give [Fe 3(CO) 11L] ( 2). In some cases ( 2), on treatment with Me 3NO and then L′ (L′ = a second two-electron donor) yields [Fe 3(CO) 10LL′] in high yield. The crystal and molecular structures of 1 (L = NCC 6H 4Me-2) have been determined by a full single crystal structure analysis, and shown to have an axial nitrile coordinated at the unique iron atom, with two CO groups bridging the other two metal atoms.