Molecular design and polymer structure control based on polymer crystal engineering. Topochemical polymerization of 1,3-diene mono- and dicarboxylic acid derivatives bearing a naphthylmethylammonium group as the countercation

The topochemical polymerization of the alkylammonium salts of (Z,Z)-, (E,Z) -, and (E,E)-1,3-diene mono- or dicarboxylic acids, i.e., of the muconic an d sorbic acid derivatives, is described from the viewpoint of polymer cryst al engineering. Not only the (Z,Z)- but also the (E,E)-derivatives polymeri ze to give a high molecular weight polymer in the crystalline state under U V irradiation when a naphthylmethylammonium moiety is introduced to these m onomers as the countercation. NMR spectroscopy confirms the formation of th e stereoregular meso- or erythro-diisotactic-trans-2,5-polymer during the p olymerization, irrespective of the configuration of the monomers and the st ructure of the substituents. The single-crystal structure analysis of the n aphthylmethylammonium salt df sorbic acid reveals the stacking of the diene moieties in the columns formed in the crystals, favorable for the topochem ical polymerization. The photopolymerization reactivity, and the stereochem istry of the resulting-polymers are determined by the molecular packing in the crystals during the topochemical polymerization of the diene monomers.