Synthesis of ladder polyaromatics as new molecular device candidates

In order to investigate one of the proposed molecular electronics switching mechanisms, we synthesized several molecules whose cores are unable to undergo conformational rotation. Preparation of these molecules, all of which are terminated with the thioacetyl moiety, takes advantage of an improved synthesis of 2,7-dibromophenanthrene, use of the reduced form of phenanthrenequinone as a protecting group, and various Sonogashira and halogen to Li to S conversions.