Organometallic polymers nucleophilic substitution

Recently, Abd-El-Aziz and colleagues reported different hyperbranched poly(arylethers) (4,5) and poly(arylthioethers) (6) containing cyclopentadienyliron moieties, which were successfully furnished by nucleophilic substitution of A + Bj type monomers (Scheme 2.3) [54], The polymers were thoroughly characterized by standard spectroscopic analysis techniques, they exhibited generally low viscosities, and the organometallic complexes were stable up to 230 °C, as evaluated by thermal gravimetric analysis (TGA). 

The synthesis of polyphosphazenes derivatized with ferrocenyl units has also been achieved by functionalization of a preformed polyphosphazene. Wisian-Neilson and Ford showed that when polymethylphenylphosphazene (66) was treated with n-BuLi, approximately half of the methyl substituents on the polymer deprotonated. These nucleophilic groups could subsequently be reacted with ferrocene derivatives as shown in Scheme 14. Polymer 68 had approximately 45% of its methyl groups converted to the organometallic groups, whereas substitution occurred at only 36% of the methyl groups in polymer 70. The presence of the ferrocenyl groups resulted in increased glass transition temperatures for these polymers. For example, when 23% substitution occurred in 70, the was 65°C, whereas a 36% substitution level resulted in a T of 87°C. ... 

Novel organometallic poly(arylene)s with 1,3-type (cyclobutadiene)cobalt moieties 27 in the main chain are prepared by Ni(0)-mediated dehalogenative polycondensation of monomers having (cyclobutadiene)cobalt moieties [51], The polymers with of 20 kDa exhibit thermotropic liquid crystallinity. The synthesis of a variety of homometallic and heterometallic oligomers and polymers such as 28 is possible via nucleophilic aromatic substitution reactions of dichlorophenylene-Fe Cp and dihydroxyphenylene-Ru Cp complexes in DMF in the presence of K2CO3 [52]. 

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