Ferrocene vinyl substituted

Vinyl-substituted ferrocenes have also been used as substrates for [2 + 2] cycloaddition to TCNE. 

In addition to benzene and naphthalene derivatives, heteroaromatic compounds such as ferrocene[232, furan, thiophene, selenophene[233,234], and cyclobutadiene iron carbonyl complexpSS] react with alkenes to give vinyl heterocydes. The ease of the reaction of styrene with sub.stituted benzenes to give stilbene derivatives 260 increases in the order benzene < naphthalene < ferrocene < furan. The effect of substituents in this reaction is similar to that in the electrophilic aromatic substitution reactions[236]. 

Many other types of polymer have been prepared which exhibit semiconductivity. All obey the equation a = a0exp — E/kT. These include xanthene polymers (109, 110), polymerized phthalocyanines (111, 112), epoxides and polydiketones (86, 113), polypentadienes (114), polydicyanoacetylenes (115), polyvinylferrocene and substituted ferrocene (116, 117, 118, 119), polymeric complexes of tetracyanoethylene and metals (120), poly(vinyl chloride) and poly(vinylidene chloride) (121), polyvinylene and polyphenylene (122) and poly(Schiff s bases) (123, 124). 

For comparison, l,l -bis(dimethylsilyl)ferrocene 4a, l,l -bis(diphenylsilyl)ferrocene 4b and 1,4-bis(dimethylsilyl)benzene 5 were also prepared and reacted with vinyl polymer 1 to form hybrid polymers 6a, 6b and 7 respectively. In the case of 6a and 7, higher reactivities of the silanes lead to gelation. While electron deficient carborane seems to reduce Si H reactivity, the conjugation effect of the aromatic system on the silicon atoms may gain the Si-H reactivity. Phenyl-substituted 6b... 

Interestingly, ferrocene (20), a nonbenzoid aromatic system, also underwent substitution reactions with vinyl compounds (e.g. styrene, acrylonitrile and methyl acrylate), albeit in lower yields [17]. For example, ferrocene (20) and styrene (4a) were oxidatively coupled in the presence of 1 eqniv Pd(OAc)2, prodncing a 20% yield of alkenylated ferrocene derivative 21 (Eqnation (9.6)). 

Ferrocene was pmchased from Aldrich and was further purified by recrystallization from ethanol in oin laboratory before use. The R-substituted trichlorosilanes R-SiCls, i.e., methyl- (Aldrich), vinyl-, n-octyl-, n-octyldecyl- (all Lancaster), n-dodecyl-, and n-hexadecylltrichlorosilanes (both UCT) were all distilled over calcium hydride. Diethyl ether, hexane, THF (all Lab-Scan), dichloromethane (DCM Aldrich), and A,A,Ar, Ar -tetrameihylethylenediamine (TMEDA Acros) were distilled from either calciiun hydride or sodium benzophenone ketyl. n-Butyllithium (1.7 M in heptane) and all other solvents and reagents were from Aldrich and were used as received. Diliihioferrocene TMEDA (4 Scheme 2) and poly[l,r-ferroceny-lene(methyl)silene] 5(1) were prepared according to published experimental proced-... 

The formation of polymetaUocenes through homoannular or heteroannular substitution is not the only method for obtaining the polymers they can also be formed by polymerization via the metal. The metallocene can be attached to the polymer chain as in poly(vinyl ferrocene) (8), or it can be an integral part of the polymer backbone (9). ... 

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