Can the radical anion of alkyl-2-cyanoacrylates initiate anionic polymerization of these instant adhesive monomers?

Electron affinities of methyl-2-cyanoacrylate (MCA) and ethyl-2-cyanoacrylate (ECA) were predicted using four different density functional or hybrid Hartree-Fock/density functional methods, Equilibrium structures and harmonic vibrational frequencies were computed for the neutral and anionic species of each system. Because of structural similarities to cyanoethylene and 1,1-dicyanoethylene, the results for MCA and ECA are compared to previous work at the same levels of theory on these two cyano-substituted ethylenes. Spin densities and isotropic hyperfine splitting constants (hfs) were determined for the radical anions of these four systems as a gauge of the delocalization of the unpaired electron. An experimental EA exists for 1,1-dicyanoethylene, although collisional electron transfer experiments on short-lived anions are questionable. The EAs for the four systems studied here are predicted to be 0.06 (cyanoethylene), 1.36 (1, 1-dicyanoethylene), and 1.08 eV (MCA and ECA). The computed spin densities and hfs constants for these radical anions indicate that the unpaired electron is primarily localized on the C atom of the CH2 segment of each molecule. 1,1-dicyanoethylene, MCA, and ECA each have two electron withdrawing groups, which results in appreciable resonance stabilization and a bound radical anion. The radical anions of MCA and ECA are nucleophilic and can attack the neutral monomer to initiate polymerization by a newly proposed mechanism.