Charge-transfer piperazine-containing polymeric systems via ring-opening metathesis polymerization

This article describes the synthesis of piperazine-containing homopolymer systems via ring-opening metathesis polymerization (ROMP). These systems were subsequently used as electron donors in the formation of charge-transfer (CT) complexes. Using exo-N-(6-bromohexyl)-7-oxabicyclo[2.2. l]hept-5-ene-2,3- dicarboxamide as a starting material, monomers were synthesized to act as electron donors. The amine group at the "open" end of the piperazine was either left open or alkylated with various alkyl groups. The monomers' ability to act as electron donors and their polymerization rates were studied. After initial photometric titration studies using 2,3-dichloro-5,6- dicyanobenzoquinone (DDQ) as an electron acceptor proved that these monomers would act as electron donors, they were subsequently polymerized into homopolymers via ROMP. The experimental results showed that a methanol:chloroform mixed solvent system enhanced the rate of polymerization over a single solvent (chloroform.) system. Studies also showed that the alkylated piperazine-containing monomer had a faster rate of polymerization than the secondary piperazine monomer. These monomers were used to make piperazine-containing homopolymers via ROMP and the resulting polymers, like the monomers, also functioned as electron donors. Potential functions of these polymers include electronics, solar cells, optical systems, and biological applications.