Organometallic polymers. XIV. Copolymerization of vinylcyclopentadienyl manganese tricarbonyl and vinylferrocene with<i>N</i>‐vinyl‐2‐pyrrolidone

Abstract

Abstract N ‐Vinyl‐2‐pyrrolidone(I) has been copolymerized with vinylferrocene(II) and vinylcyclopentadienyl manganese tricarbonyl(III) in degassed benzene solutions with the use of azobisisobutyronitrile (AIBN) as the initiator. The polymerizations proceed smoothly, and the relative reactivity ratios were determined as r 1 = 0.66, r 2 = 0.40 (for copolymerization of I with II, M 1 defined as II) and r 1 = 0.14 and r 2 = 0.09 (for copolymerization of I with III, M 1 defined as III). These copolymers were soluble in benzene, THF, chloroform, CCl 4 , and DMF. Molecular weights were determined by viscosity and gel‐permeation chromatography studies (universal calibration technique.) The copolymers exhibited values of M̄ n between 5 × 10 3 and 10 × 10 3 and M̄ w between 7 × 10 3 and 17 × 10 3 with M̄ w /M̄ n &lt; 2. Upon heating to 260°C under N 2 , copolymers of III underwent gas evolution and weight loss. The weight loss was enhanced at 300°C, and the polymers became in creasingly insoluble. Copolymers of vinylferrocene were oxidized to polyferricinium salts upon treatment with dichlorodicyanoquinone (DDQ) or o ‐chloranil (o‐CA) in benzene. Each unit of quinone incorporated into the polysalts had been reduced to its radical anion. The ratio of ferrocene to ferricinium units in the polysalts was determined. The polysalts did not melt at 360°C and were readily soluble only in DMF.