Vacuum-processable ladder-type oligophenylenes for organic–inorganic hybrid structures: synthesis, optical and electrochemical properties upon increasing planarization as well as thin film growth

A novel synthetic route to even-numbered ladder-type oligo(p-phenylene)s (LOPPs) carrying no solubilizing groups to facilitate vacuum-processing is presented. The influence of increasing bridging adjacent phenylene units on the optical and electrochemical properties is discussed in the series of p-sexiphenyl 6P, terfluorene 3F, and ladder-type sexiphenyl L6P. The influence of the extension of the π-system is taken into consideration as well. Furthermore it is shown that highly ordered thin films of L6P on alumina surfaces can be prepared by organic molecular beam deposition (OMBD).