Polymerizations, radical butadiyne

A pair of Ullman s nitronyl nitroxide radicals carrying m- and p-ethynylphenyl groups at position 2 of the imidazoline ring (7 and 8) are quite stable at room temperature under air and the unpaired electrons withstand the catalyzed polymerization conditions (see Section 11.4.3) [6]. The terminal ethynyl groups are not susceptible to Pb02 in benzene/metha-nol at room temperature, which is used for the oxidation of the bis(hydroxylamine)s to the nitronyl nitroxides [6, 7]. Fremy s salt gives the best result for the oxidation of the hydroxyl-amine 14 carrying a terminal 1,3-butadiyne moiety [9]. 

Polymerization has been attempted b conventional free radical, cationic and anionic initiators. Reactivity was observed, but a well defined polymer structure was not characterized. Butadiyne has been reported to fonj condensation copol3r-mers b nucleophilic addition of diamines or heterocyclic compounds. From its structure as the simplest diacetylene, it would be expected to figure prominently in solid state diacetylene polymerizations (Eq. 1). In one instance Wegner does... 

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