6533b823fe1ef96bd127fdd9

RESEARCH PRODUCT

false

subject

description

ESR spectroscopic analyses of the deep-green solutions of living poly(2-isopropenylnaphthalene) [poly(2-IPN)] in THF at −80°C provided no evidence of the presence of radical anions as long as butyllithium (BuLi) was used as initiator. In contrast to this finding, radicals could indeed be detected if the polymerization was performed with metallic potassium in THF. These radicals were found to be only stable at low temperatures. UV/VIS spectra of solutions of 2-IPN in THF or toluene and of catalytic quantities of BuLi were recorded at temperatures between −45 and +20°C. On heating to >0°C, the colour of the deep-green solution changes irreversibly to reddish-brown, and this colour change is associated with a spontaneous deactivation of the living poly(2-IPN). End-capping reactions with anthracene derivatives and the block copolymerization with hexamethylcyclotrisiloxane gave a first idea of the reactivity and structure of the species present in the reddish-brown solution. A suggestion is made for the deactivation mechanism.