Ladder-Type Polymers with 2-Carbon Bridges

Ladder-Type Polymers with 2-Carbon Bridges... 

In 1993, Scherf and Chmil described the first synthesis of a ladder-type poly(pflra-phenylene-czs-vinylene) (116) [138]. On the one hand, ladder polymer 116 represents, a planar poly(phenylene) containing additional vinylene bridges on the other hand, it is a poly(phenylenevinylene) with aryl-aryl linkages in the polymeric main chain. The target macromolecules, as fully aromatic ladder polymers, are composed of all-carbon six-membered rings in the double-stranded main chain (an example of angularly annelated poly(acene)s). 

Scheme 2 Synthesis of ladder-type polyphenylenes using para- and meto-dibenzoyl benzene building blocks, and dehydrogenation of 3b to polymer 3 with para-quinodimethane repeat units. No control over the configuration at the bridging methylene carbons could be achieved...

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