Synthesis of 7,8-bis(benzyloxycarbonyl)-7,8-dicyanoquinodimethane, polymerization, and some properties of its polymer

Abstract

7,8-Bis(benzyloxycarbonyl)-7,8-dicyanoquinodimethane (1d) was prepared successfully as isolable crystals at room temperature and determined to have an anti-form by 1H-NMR spectroscopy. When 1d was dissolved in basic polar solvents such as acetonitrile, acetone, tetrahydrofuran, dimethyl sulfoxide, and N,N-dimethylformamide, spontaneous polymerization took place to give polymers with Mn of 6 x 103 to 9.7 x 105. 1d is homopolymerizable with 2,2'-azobis(isobutyronitrile) (AIBN) as a radical initiator, triethylamine, proton sponge, and triphenylphosphine, but not with boron trifluoride diethyl etherate as a cationic initiator. 1d copolymerized with styrene (St) in the presence of AIBN in chloroform to obtain the monomer reactivity ratios r1 (1d) = 3.1 ± 0.5 and r2(St) = 0.030 ± 0.01 at 60 ° C, and Q and e values of 9.3 and + 0.73, respectively, indicating that 1d is highly conjugative and electron-accepting. The thermal behavior and photodegaradation for poly(1d) were investigated in comparison with the polymer of 7,8-bis(butoxycarbonyl)-7,8-dicyanoquinodimethane (1c).