Design of Narrow-Bandgap Polymers. Syntheses and Properties of Monomers and Polymers Containing Aromatic-Donor and o -Quinoid-Acceptor Units

  • 10.1021/cm950467m
  • Chemistry of Materials
  • p 570-578, Volume 8, Issue 2,
  • journal-article
A series of novel monomers and polymers containing aromatic-donor and o-quinoid-acceptor units was prepared, and the relationship between their spectral and electrochemical properties and their structures was investigated. X-ray structure analyses of the monomers possessing thiophene units revealed coplanar conformations, whereas calculations of the monomers containing N-methylpyrrole showed torsional conformations. Cyclic voltammetry showed amphoteric properties for all the monomers and p- and n-doping processes for most of the polymers. The reduction potentials were primarily dependent on the electron-accepting character of the o-quinoid-acceptor units. The electrochemical behavior of the polymers was characterized by cyclic voltammetry and suggested narrow-bandgap systems. The bandgaps determined from optical absorption spectra range from 0.5 to 1.4 eV. The polymer composed of thiophenes and benzo[1,2-c;3,4-c‘]bis[1,2,5]thiadiazole exhibited the narrowest bandgap.


Better yields with slight optimizations

This paper describes the synthesis and characterization of a series of thiophene- and N-methylpyrrole-based low band gap polymers incorporating o-quinoid acceptors such as thienopyrazine, quinoxaline, benzothiadiazole, pyrazinoquinoxaline, thiadiazoloquinoxaline and...