Synthesis and characterization of η5-tetramethylcyclopentadienyl-hydrido- and -chloro-silyl-η1-amido zirconium complexes

Abstract

The silylated tetramethylcyclopentadienes C 5

Hydro- and chloro-substituted silyl- and silyl-η1-amido-η5-tetramethylcyclopentadienyl titanium complexes

“…Alternatively complex 8 may also be prepared by reaction of the dilithium salt Li 2 [C 5 Me 4 SiMeH(N t Bu)] [9] with an equimolar amount of TiCl 3 (THF) 3 in THF, followed by addition of PbCl 2 as oxidant [20] and appropriate work up of the resulting solution. This result indicates that there is no interaction between the boron Lewis acid and the amido-N probably due to the low nucleophilic character imposed by the strong p-donation to the zirconium centre.…”

“…In particular we were interested in metal complexes with chloro-silyl bridging groups for which many synthetic constraints were reported [8]. In previous work we reported [9] that chlorination of the hydro-silyl zirconium complex [Zr (h 5 -C 5 3 ] were studied by X-ray diffraction methods.…”

Synthesis and Reactivity of a Silylalkyl Double Tuck‐in Uranium Metallocene [(η5:η1‐C5Me4SiMe2CH2)2U] and its Conversion to Bis(tethered) Metallocenes

“…Synthesis of actinide complexes with the (C 5 Me 4 SiMe 3 ) À ligand were initially being explored as part of an effort to obtain more soluble actinide metallocenes. The (C 5 Me 4 SiMe 3 ) À ligand was shown to be a viable replacement for (C 5 Me 5 ) À with early transition metals [5][6][7][8][9][10][11][12][13] and lanthanides. [14][15][16][17][18][19][20] With the latter metals, this ligand has led to spectacular mono-ring chemistry.…”

Synthesis and reactivity of imido niobium complexes containing the functionalized (dichloromethylsilyl)cyclopentadienyl ligand

“…In this case, the 1 H NMR spectrum of 5 again showed an AA 0 BB 0 pattern, after recovering the C s symmetry; meanwhile, the 29 Si NMR spectrum showed a resonance shifted highfield (d À29.0), due to the presence of two p donor amido ligands bound to the silicon atom [29,30]. Furthermore, the resonances at low field of the H-N niobium-amido groups disappeared, although the new resonances for the siliconamido ligands could not be observed.…”

“…These two types of compounds offered the opportunity to introduce a chelating cyclopentadienyl silyl-g-amido ligand whilst still leaving a second reactive point at the cyclopentadienyl ligand. The first type of complex can be illustrated by the reported constrained geometry group 4 metal complexes with one additional Si-X bond (X = H, Cl, NHtBu) [28][29][30], which were suitable to explore further reactivity of these bonds. Furthermore, hydrolysis of the Si-Cl bond of the starting [Ti{g 5 -C 5 R 4 (SiCl 2 Me)}Cl 3 ] (R = H, Me) complexes gave dinuclear compounds with Si-O-Ti [28] bridges and one additional Si-O-Si bridge (for R = Me) [31].…”