Organometallic polymers cyclobutadiene complexes

Scherf, U., Stitzer, K., zur Loye, H.-C., and Bunz, U.H.F. (2001) Conjugated organometallic polymers containing Vollhardt s cyclobutadiene complex aggregation and morphologies. Ghem. Ear. 

Altmann, M. and U.H.F. Bunz. 1995. Polymers with complexed cyclobutadiene units in the main chain—the first example of a thermotropic, liquid crystalline organometallic polymer. Angew Chem 34 569. 

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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