The synthesis and chemistry of transition-metal complexes incorporating sila- and germaaromatic ligands.

摘要

This thesis describes the syntheses of the first examples of early transition metal sila- and germacyclopentadienyl complexes and late transition metal complexes with neutral 6pi-electron ligands containing silicon.;Reactions of silolyl and germolyl salts of the type M[C4Me 4ER] (M = Li, K; E = Si, Ge; R = alkyl, silyl, aryl) with early metal halides were investigated. K[C4Me4ESiMe3] reagents react with Cp*MCl3 (M = Zr, Hf) to give the first examples of eta5-silolyl and eta5-germolyl complexes of d0-transition metals. Li[C4Me4GeSiMe 3] reacts with Cp*HfMe2Cl to give a complex of the aromatic germole dianion, [Cp*(eta5-C4Me4Ge)HfMe 2Li(THF)]2, while reagents of the form Li[C4Me 4GeR] (R = alkyl, aryl) react with Cp*HfMe2Cl to give the products of methyl migration, Cp*(eta4-C4Me 4GeMeR)HfMe. The reaction chemistry of these complexes was thoroughly investigated.;The use of C4Me4GeMeSiMe3 as a germolyl transfer reagent was studied. C4Me4GeMeSiMe3 reacts with TaCl5 with loss of Me3SiCl to give the product of chloride transfer to germanium, [(eta4-C4Me 4GeMeCl)TaCl3(Et2O)x]2 (x = 0.5--1.0). The latter compound reacts with various 2-electron donors to give stable adducts, and its reaction with CpTl gives air-stable Cp(eta 4-C4Me4GeMeCl)TaCl2. The reaction chemistry of these compounds was investigated.;The syntheses of complexes of Ru are described, including the first examples of complexes containing eta5-Si(tBuNCHCHN tBu) and eta6-silabenzene ligands. Si(tBuNCHCHNtBu) reacts with [Cp*Ru(NCMe)3]OTf to give [Cp*Ru({eta1-S i(tBuNCHCHNtBu)}(NCMe)2]OTf. Heating this complex in THF results in precipitation of the crystalline complex [Cp*Ru{eta5, eta1-Si(t BuNCHCHNtBu)}Cp*Ru(NCMe)2](OTf) 2. Li[C5H5SitBu] reacts with [Cp*RuCl] 4 to give the neutral silacyclohexadienyl complex Cp*Ru[eta 5-C5H5SiH(tBu)]. The latter complex reacts with B(C6F5)3 to give the first example of a silabenzene complex, [Cp*Ru(eta6-C5H 5SitBu)][BH(C6F5)3]. Finally, trans-1,4-dihydrohexamethyl-1,4-disilacyclohexa-2,5-diene reacted with Cp'(PMe3)2RuCH 2SiMe3 (Cp' = C4Me4 Et) to give Cp'(PMe3)RuH(eta 2-hexamethyl-1,4-disilabenzene), whose structure (by X-ray crystallography) may be described as possessing a metallo-disila-norbornadiene structure.