Electronic structure of some conjugated polymers for electron transport
2001 (English)In: Synthetic metals, ISSN 0379-6779, Vol. 122, no 1, 67-72 p.Article in journal (Refereed) Published
The chemical and electronic structure of three different, strictly alternating copolymers, poly(2,5-diheptyl-1,4-phenylene-alt-1,4-naphthylene) (P14NHP), poly(2,5-diheptyl-1,4-phenylene-alt-2,6-naphthylene) (P26NHP) and poly(2,5-diheptyl-1,4-phenylene-alt-9,10-anthrylene) (P910AHP), have been studied by photoelectron spectroscopy and optical absorption spectroscopy. The experimental results have been analyzed using the results of quantum chemical calculations. In the geometrical structure of all three of the polymers there are large torsion angles between the phenylene unit and the naphthylene or anthrylene units. These large torsion angles lead to localization of the p-electron wave functions, and minimal conjugation along the polymer backbone. For all three polymers, the highest occupied molecular orbital is completely localized to the naphthylene or anthrylene unit. The frontier molecular orbital wave functions are very reminiscent of the highest occupied orbitals of the isolated naphthalene or anthracene molecules. The optical absorption spectra of all three polymers verify the existence of large optical band gaps, consistent with the large torsion angels. The first several optical transitions in the polymers are also very reminiscent of the transitions in single naphthalene and anthracene molecules.
Place, publisher, year, edition, pages
2001. Vol. 122, no 1, 67-72 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-47395DOI: 10.1016/S0379-6779(00)01365-5OAI: oai:DiVA.org:liu-47395DiVA: diva2:268291