THE SYNTHESIS, CHARACTERIZATION, AND REACTIVITY OF IRON CARBONYL CLUSTERS INCORPORATING MAIN GROUP HETEROATOMS

[摘要] The reaction of Pb(OAc)$sb2$ or PbCl$sb2$ with K (HFe(CO)$sb4$) results in formation of (Et$sb4$N) $sb2$ (Pb${$Fe$sb2$(CO)$sb8}{$Fe(CO)$sb4}sb2$) in high yield based on iron. This complex has been structurally characterized and contains a central Pb$sp{4+}$ atom bound to two (Fe(CO)$sb4$) $sp{2-}$ ligands and one (Fe$sb2$(CO)$sb8$) $sp{2-}$ group (Fe-Fe = 2.617(5)A). (Et$sb4$N) $sb2$ (M${$Fe$sb2$(CO)$sb8}{$Fe(CO)$sb4}sb2$) reacts with CO and MCl$sb2$ with excess K (HFe(CO)$sb4$) to yield products which are formulated as (Et$sb4$N) $sb2$ (M${$Fe(CO)$sb4}sb2$) on the basis of analytical and spectroscopic data. GeI$sb2$ is unreactive towards K (HFe(CO)$sb4$), but when mixed with (Et$sb4$N) $sb2$ (Fe$sb2$(CO)$sb8$) formation of the novel complex (Et$sb4$N) $sb2$ (Fe$sb3$(CO)$sb9(musb3$-CO)${musb3$ - GeFe(CO)$sb4}$) occurs. When GeCl$sb4$ is treated with (Et$sb4$N) $sb2$ (Fe$sb2$(CO)$sb8$) formation of (Et$sb4$N) $sb2$ (Fe$sb3$(CO)$sb{11}$) is observed with no evidence of a germanium-containing cluster. These mixed metal anions are oxidized by (Cu(CH$sb3$CN)$sb4$) (BF$sb4$) to form the corresponding neutral spirocyclic M (Fe$sb2$(CO)$sb8$) $sb2$ (M = Sn, Ge, Pb) species. A single crystal X-ray diffraction structure was obtained for the complex Pb (Fe$sb2$(CO)$sb8bracksb2$ (Fe-Fe = 2.90(2)A). Reduction of Ge (Fe$sb2$(CO)$sb8bracksb2$ in benzene or CH$sb2$Cl$sb2$ led to the recovery of (Et$sb4$N) $sb2$ (Fe$sb3$(CO)$sb9(musb3$-CO)${musb3$-GeFe(CO)$sb4$). (Et$sb4$N) $sb2$ (Pb${$Fe$sb2$(CO)$sb8}{$Fe(CO)$sb4}sb2$) or (Et$sb4$N) $sb2$ (Pb${$Fe(CO)$sb4}sb2$) are recovered from reduction of Pb (Fe$sb2$(CO)$sb8$) $sb2,$ depending on the solvent used.Periodic trends were examined by utilizing bismuth as the main group element. The reaction of NaBiO$sb3$ with K (HFe(CO)$sb4$) resulted in isolation of (Et$sb4$N) $sb3$ (Bi${$Fe(CO)$sb4}sb4$) in which a central Bi$sp{5+}$ atom is tetrahedrally surrounded by four (Fe(CO)$sb4$) $sp{2-}$ ligands. This complex decomposes in the presence of gaseous HCl to produce up to 1 mole of H$sb2$ per mole of cluster via intermediate formation of H$sb2$Fe(CO)$sb4.$ Refluxing NaBiO$sb3$ with Fe(CO)$sb5$ led to the isolation of (Et$sb4$N) (BiFe$sb3$(CO)$sb9(musb3$-CO)) which is isoelectronic with (Et$sb4$N) $sb2$ (Fe$sb3$(CO)$sb9(musb3$-CO)${musb3$-GeFe(CO)$sb4}$) and contains a triangle of iron atoms capped by a bismuth atom on one face and a CO group on the other (Fe-Fe = 2.642(7)A).When (Et$sb4$N) (BiFe$sb3$(CO)$sb9(musb3$-CO)) is treated with CO, an extensive rearrangement occurs leading to formation of (Et$sb4$N) $sb2$ (Bi$sb4$Fe$sb4$(CO)$sb{13}$) in which there is a central tetrahedron of bismuth atoms attached to iron carbonyl fragments. This complex is the first ;;Zintl-metal carbonylate;; to be reported. (Abstract shortened with permission of author.)

[发布机构] Rice University

[效力级别] chemistry