Effects of Olefin Content and Alkyl Chain Placement on Optoelectronic and Morphological Properties in Poly(thienylene vinylenes)

The effects of olefin content and alkyl chain placement on the properties of two poly(thienylene vinylene)- (PTV-) based polymer series were investigated. Polymers were prepared by ruthenium-catalyzed acyclic diene metathesis (ADMET) polymerization of four dipropenyl monomers. All polymers were thoroughly characterized with a variety of spectroscopic, thermal, and electronic techniques. Tuning the olefin content had direct impacts on optical and organic solar cell (OSC) behavior while systematic changes to alkyl substitution patterns manifested as differences in optical, thermal, and microstructural properties. Density functional theory (DFT) analysis provided support for the observed differences among all polymers. In addition, 13C NMR and IR analysis of selected polymers helped to confirm the stereochemistry of the PTV backbone.