The synthesis, characterization and intramolecular dynamics of heavy main-group iron carbonyl compounds

[摘要] The reaction of TlCl$sb3cdot$4H$sb2$O with a methanolic KOH solution of Fe(CO)$sb5$ is known to produce $lbrackm Etsb4Nbracksb2lbrack Tlsb2Fesb4(CO)sb{16}brack$ which serves as a precursor for several Tl-Fe carbonyl compounds. When a solution of $lbrackm Etsb4Nbracksb2lbrack Tlsb2Fesb4(CO)sb{16}brack$ is allowed to stand in the sunlight for long periods of time, three new thallium-iron carbonyls are also known to result: $lbrackm Etsb4Nbracksb2lbrack Tlsb2Fesb6(CO)sb{24}brack$, $lbrackm Etsb4Nbracksb4lbrack Tlsb4Fesb8(CO)sb{30}brack$ and $lbrackm Etsb4Nbracksb6lbrack Tlsb6Fesb{10}(CO)sb{36}brack$. $lbrackm Etsb4Nbracksb2lbrack Tlsb2Fesb6(CO)sb{24}brack$ may be synthesized by oxidation of $lbrackm Etsb4Nbracksb2lbrack Tlsb2Fesb4(CO)sb{16}brack$ with $lbrackm Cu(MeCN)sb4bracklbrack BFsb4brack$ or by placing a solution of $lbrackm Etsb4Nbracksb2lbrack Tlsb2Fesb4(CO)sb{16}brack$ or $lbrackm Etsb4Nbracklbrack (tmeda)TlFesb2(CO)sb8brack$ and Fe(CO)$sb5$ in the sunlight. $lbrackm Etsb4Nbracksb2lbrack Tlsb2Fesb4(CO)sb{16}brack$ also reacts with various bidentate Lewis bases (L) to form adducts of general formula $lbrackm Etsb4Nbracklbrack (L)TlFesb2(CO)sb8brack$, several of which have been structurally characterized. The indium analogues of $lbrackm Etsb4Nbracksb2lbrack Tlsb2Fesb6(CO)sb{24}brack$ and $lbrackm Etsb4Nbracklbrack (L)TlFesb2(CO)sb8brack$ have been synthesized by addition of InCl$sb3$ to K (HFe(CO)$sb4$), and addition of Lewis bases to $lbrackm Etsb4Nbracksb2lbrack Insb2Fesb4(CO)sb{16}brack$, respectively. The photolysis of a solution of $lbrackm Etsb4Nbracksb2lbrack Insb2Fesb4(CO)sb{16}brack/Fe(CO)sb5$ also affords $lbrackm Etsb4Nbracksb2lbrack Insb2Fesb6(CO)sb{24}brack$.The reaction of PbCl$sb2$ with a methanolic KOH/Fe(CO)$sb5$ solution produces two compounds, depending upon the ratio of starting reagents used: $lbrack m Etsb4Nbracksb2lbrack PbFesb4(CO)sb{16}brack$ and $lbrack m Etsb4Nbracksb2lbrack Pb{Fe(CO)sb4}sb3brack$. Similarly, $lbrack m Etsb4Nbracksb2lbrack Sn{Fe(CO)sb4}sb3brack$ is synthesized by reaction of SnCl$sb2$ with K (HFe(CO)$sb4brack$. A variable temperature $sp{13}$C-NMR study of $lbrackm Etsb4Nbracksb2lbrack EFesb4(CO)sb{16}brack$, E = Sn, Pb, $lbrack m Etsb4Nbracksb2lbrack Pb{Fe(CO)sb4}sb3brack$ and PbFe$sb4$(CO)$sb{16}$ has been undertaken in order to understand the rearrangement processes of the carbonyl ligands occurring in solution. The single crystal X-ray structures of $lbrack m Etsb4Nbracksb2lbrack SnFesb4(CO)sb{16}brack$ and $lbrack m Etsb4Nbracksb2lbrack E{Fe(CO)sb4}sb3brack$, E = Sn, Pb, are also reported.The reduction of Ph$sb2$BiCl with two equivalents of sodium in liquid NH$sb3$ followed by addition of Fe(CO)$sb5$ yields two main products, $lbrack m PhBiFe(CO)sb4bracksb2$ and (Ph$sb2$Bi)$sb2$Fe(CO)$sb4$, along with traces of Ph$sb4$Bi$sb2$. Evidence supports (Ph$sb2$Bi)$sb2$Fe(CO)$sb4$ as an intermediate in the formation of $lbrack m PhBiFe(CO)sb4bracksb2$. Treatment of Na$sb2$Fe(CO)$sb4$ with one equivalent of Ph$sb2$BiCl in tetrahydrofuran affords Na$lbrackm Phsb2BiFe(CO)sb4brack$, characterized as the (PPN) $sp+$ salt. Adding a second equivalent of Ph$sb2$BiCl to the same reaction produces (Ph$sb2$Bi)$sb2$Fe(CO)$sb4$ or $lbrackm PhBiFe(CO)sb4bracksb2$, depending on the reaction time. (PhBiFe(CO)$sb4bracksb2$ is also obtained in poor yield from the reaction of PhBiBr$sb2$ and Na$sb2$Fe(CO)$sb4{cdot}3/2$ dioxane in THF. (PhBiFe(CO)$sb4bracksb2$, (PPN) (Ph$sb2$BiFe(CO)$sb4brack$ and (Ph$sb2$Bi)$sb2$Fe(CO)$sb4$ have been characterized by single crystal X-ray diffraction.

[发布机构] Rice University

[效力级别] chemistry