Silane, cyclopentadienyl

The molar ratio of the III compound to the V compound is typically l/lO.t ] To obtain the desired semiconductor properties, dopants are added such as zinc (from diethyl zinc) or magnesium (from bis(cyclopentadienyl) magnesium) for p doping, and silicon (from silane) or selenium (from hydrogen selenide) for n doping. 

An interesting compound is formed in the reaction of dimethyl-bis(cyclopentadienyl)silane with iron pentacarbonyl, in refluxing octane [its structure was confirmed by X-ray diffraction (/6i)] ... 

Dialkylbis(cyclopentadienyl)silanes can be used in a similar manner, as in the following preparation of a titanium derivative (R = Me) (96) ... 

Dehydrogenative Coupling. Transition-metal catalyzed polymerization of silanes appears to hold promise as a viable route to polysilanes. A number of transition-metal complexes have been investigated, with titanium and zirconium complexes being the most promising (105—108). Only primary silanes are active toward polymerization, and molecular weights are rather low. The dehydrogenative polymerization is depicted in reaction 11, where Cp = cyclopentadienyl ... 

Cyclopentadienyl compounds of lithium, sodium, potassium, magnesium and thallium are most commonly used. The synthesis of these cyclopentadienyl-transfer agents is described in more detail in Section II.B.2. Organosilicon halides and alkoxides are the most convenient substrates. The synthesis of side-chain functionalized cyclopentadienyl silanes is described in equation 541,42 as a typical example of this strategy. 

Reactions of silanes with cyclopentadienyl Ta imides are a new method to yield hydrides. Addition of the... 

Three classes of hybrid HPA are known to be stable to hydrolysis 1. Organometallic derivatives of the type RM (M = Si, Ge, Sn, Pb and R = alkyl or aryl). 2. Cyclopentadienyl-titaninm derivatives. 3. Zirconium alkoxide or phosphate derivatives, all of which are illustrated in Figure 2. We have tested phenyl model compounds of all of these for stability by boiling them in 6M HCl or H2O2 solution. This study showed that only PhP-O-HPA moieties are stable under conditions likely to be encountered in a fuel cell. Never the less we continue to study model compounds of the type RSi-O-HPA due to the large diversity of available ethoxy- and chloro- silanes. 

The synthesis and characterization of enantiomerically pure ansa-cyclopentadienyl organolanthanides Me2Si(ButCp)[(+)- i o-Men-Cp]Ln(CH(SiMe3)2 and their use as precatalysts for asymmetric olefin hydrogenation have been reported. In a one-pot reaction starting from 6,6-dimethylfulvene, methyllithium, and dimethyldichloro-silane the desired product Me2Si(ButCp)Cl was obtained, which was alkylated with Na[(+)-row-Men-Cp] to afford the neutral ligand. Reaction with BunLi afforded the dilithium salt as a colorless crystalline solid (Scheme 161). 

---