Trimethylsilylmethyl complexes

Arndt, S., Zeimentz, P.M., Spaniol, T.P. etal. (2003) Neutral and cationic trimethylsilylmethyl complexes of the rare earth metals supported by a crown ether synthesis and structural characterization. Dalton Transactions, 3622. 

Pendant-arm amido-cyclopentadienyl ligands have also been shown to be useful in the stabilization of highly reactive mono(cyclopentadienyl)lanthanide alkyl and hydrido complexes. When the tris(trimethylsilylmethyl) complexes of lutetium and ytterbium, Ln(CFI2SiMe3)3(TFIF)2, were treated in pentane solution with 1 equiv. of (CsMe4H)SiMe2NHCMe2R (R = Me, Et) at 0°C, the new complexes (rfir)1-... 

Analogous compounds are formed during the thermodecomposition of individual trimethylsilylmethyl complexes of Er and Lu, which slowly proceeds at room temperature [53, 54] ... 

Trimethylsilylmethyl complexes of Y,Er and Yb have been obtained in the interaction of Mc3SiCH2Li with LnCl3 [44, 53]. These compounds also contain stabilizing donating ligands Et20, THF, TMED. The ether in these complexes can be easily substituted by more donating TMED ... 

The products isolated in 50-55% yield are unstable. The trimethylsilylmethyl complex is especially unstable it decomposes in toluene even at room temperature. The analogous La and Sm compounds are even less stable. The attempts to prepare them using the same method have failed. 

A number of trimethylsilylmethyl and related complexes have been converted into others by standard ligand displacement procedures from... 

Dialkyl zinc compounds form phosphine complexes of formula RZnP(SiMe3)2 on addition of one equivalent of bis(trimethylsilyl)phosphine. Solution and solid-state studies showed that the complexes are dimeric or trimeric in solution or the solid state. Bis(trimethylsilyl)phosphido-methylzinc crystallizes as a trimeric molecule with a Zn3P3 core in the twist-boat conformation. Bis(trimethylsilyl)phosphido- -butylzinc, shows a similar central Zn3P3 fragment. The sterically more demanding trimethylsilylmethyl substituent forms a dimeric species of bis(trimethylsilyl) phosphido-trimethylsilylmethylzinc. Solution studies of bis(trimethylsilyl)phosphido- .vo-propyl-zinc demonstrate a temperature-dependent equilibrium of the dimeric and trimeric species and the crystalline state contains a 1 1 mixture of these two oligomers. A monomeric bis(trimethyl-silyl)phosphido-tris(trimethylsilyl)methylzinc has also been synthesized.313... 

In many of the reported preparations of stable carbene complexes from alkyl complexes, alkyl groups without p-hydrogen (e.g. neopentyl, 2,2,2-trifluoroethyl, trimethylsilylmethyl, methyl, benzyl) were chosen in order to avoid p-elimination. There are, however, also examples of moderately stable, non-heteroatom-substituted alkylidene complexes with hydrogen in the -position to the metal (see, e.g.. Figure 3.8). 

Dioxazolines, synthesis, 30 271 Dioximes, technetium(III) complexes, 41 33-36 Dioxocyclam, 45 96 Dioxohexakis(trimethylsilylmethyl)-... 

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