Polymers Containing Complexed 5-Membered Rings

Polymeric pseudocrown ether resins, containing azathiacrown and oxacrown ethers in 13- and 19-membered rings, were prepared as shown for the former in Scheme 28 <1997JAPS931>. The polymers adsorbed noble metals well. IR spectra of the polymeric azacrown ethers and photoelectron spectra of the uncomplexed and metal-complexed reagents were reported. 

The polymers with trans-fused five-membered rings linked with a diisotactic head-to-tail sequence have chirality, although the polymers composed of the cis-fused ring are achiral. Scheme 10 summarizes the structures of the stereoisomeric polymers. The optically active zirconocene complex with a C2 symmetric structure catalyzes the enantioselective cyclopolymerization of 1,5-hexadiene (Eq. 20) [98, 99]. Although the polymer contains not only trans-fused ring but also cis-fused ring units (ca. 68 32), it shows optical rotation due to the main chain chirality. 

The coordination of tricarbonylmaganese and pentamethylcyclopentadienylcobalt to poly(9-hexylfluorene) was examined (Scheme 2.60).274 Polymer 226 contained both 5- and 6-membered aromatic rings that can coordinate the transition metal complexes however, studies indicated that the coordination to the 5-membered ring was preferred. Reaction of 226 with MnBr(CO)5 yielded polymer 227 with a ratio of 1 1.5 for the complexed to the uncomplexed rings however, reaction of 226 with BuLi followed by (C5Me5)Co(acac) and then oxidation of the solution with HC1 gave polymer 228. Polymer 228 was determined to be a mixture of... 

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