Infrared absorption spectra of polystyrene doped with some charge-transfer complexes

Abstract

The IR absorption spectra of thin films of pure polystyrene (PS) and PS doped with acceptors [tetracyanoquinodimethane (TCNQ), tetracyanoethylene (TCNE) and chloranil], donors (anthracene, Rhodamine 6G and Acridine Orange) and acceptor-donor systems have been investigated. Close comparison of the IR spectra PS films doped with donor or acceptor with the films doped with donor-acceptor systems showed that new bands appeared in spectra of the complexed donor-acceptor PS films. These bands were assigned to molecular interaction between acceptor and donor molecules on the one hand and the interaction of acceptor and donor molecules separately with PS molecules on the other. The results indicate that some bands in the IR spectra of donor-acceptor PS films show frequency and intensity changes when compared with the absorption bands of PS. The molar energies possessed by PS, PS donor or acceptor complexes and donor-acceptor complexes were calculated. From these calculations the stabilities of the complexes formed in PS films were determined.