New organic polymer precursors: Synthesis and electronic structure of thienylpyridines and thienylethynylpyridines

He I and He II UV photoelectron spectra (UPS) of isomeric thienylpyridines and thienylethynylpyridines have been recorded. Their electronic structures were analysed and spectra assigned on the basis of He II/He I intensity variations, comparison with UPS of pyridine, thiophene and ethyne and semiempirical MO calculations. The spectra indicate that there is considerable interaction between π orbitals of thiophene, pyridine and ethynyl moieties. The relationship between electronic structure and formation of novel polymer materials is discussed.