π-electron delocalization in poly(pphenylene), poly(pphenylenesulfide), and poly(pphenyleneoxide)

Abstract
As deduced from electron-energy-loss experiments, the π band in poly(pphenylene) has a width comparable to that in graphite. The π-band width in poly(pphenylenesulfide) is considerably narrower, and in poly(pphenyleneoxide) the π electrons are localized in benzene-derived states. These results are in line with recent theoretical results. In addition, structure in the C1sπ* absorption is shown to be due to chemical shifts of C atoms in different coordination.