Spontaneous ring-collapsed alternating copolymerization of a homocyclic arsenic compound and phenylacetylene

Without any added catalyst or radical initiator at 25 degreesC, cyclo-(MeAs)(5) caused cleavage of the arsenic-arsenic bond spontaneously and copolymerized with phenylacetylene (PA) in chloroform to give a novel organoarsenic polymer having a methylarsine (MeAs) unit and a vinylbenzene unit alternating in the main chain, -[AsMe-CH=CPh](n)-. The rate of monomer consumption during the copolymerization was followed by a gas chromatography (GC) analysis, and the increase of the molecular weight of the resulting copolymer was monitored by GPC measurement. These analyses revealed that this system was step-reaction polymerization. The consumption of PA during the copolymerization with cyclo-(MeAs)(5) using AIBN was much faster as compared to the case without AIBN.