Isopropenylferrocene monomer

Ferrocene Monomers. Although the isopropenylferrocene monomer has been reported previously by several groups of investigators,34-37 we were able to develop a more facile, dependable, high yield synthesis for this compound, utilizing the three-step procedure shown below ... 

In the copolymerization of isopropenylferrocene with a-methyl-styrene at 0°C, using varying molar ratios of isopropenylferrocene and a-methylstyrene, traces of polymer formation were obtained only at a 30/70 ratio of the two monomers, as shown in the data in Table III. Because a-methylstyrene has a much lower ceiling temperature than styrene, we also decided to use styrene as a comonomer under conditions similar to those employed with a-methylstyrene. The reaction temperature for the copolymerization with a-methylstyrene was 20°C. 

All of these observations on the copolymerizations of isopropenylferrocene can again be attributed to the extreme stability of the intermediate carbenium ions. In order to obtain more conclusive evidence of this unreactivity, an attempt was made to destabilize the vinylferrocene by introducing a deactivating electron-withdrawing trifluoromethyl substituent at the a-position. For this purpose, the new monomer a-trifluoromethylvinylferrocene (TVF) was synthesized by the route shown below 0... 

Isopropenylferrocene does not homopolymerize under free radical conditions using AIBN as an initiator, but it does copolymerize with styrene.Preliminary results indicate that the IDM monomer also copolymerizes with styrene using AIBN. In benzene solvent at 50°C in 24 h, a 10.6% yield of copolymer (IR vc=0 2020, 1945 cm , vN=0 1675 cm-- -, V q 1601 cm-- -, v 3020 cm-- -) resulted having an M f 5700 and containing 6.8% of IDM as determined by elemental analysis. The initial monomer mixture contained 17% of IDM. 

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