Abstract: Kim Mullane
Mentor: Frank Mallory
[n]Phenacenes are molecules containing n aromatic rings joined together in a zigzag pattern. Since they can be thought of as graphene ribbons, which have conductive properties, they should have the potential to be used as molecular wires. The solubility of unsubstituted [n]phenacenes decreases dramatically with increasing n; phenacene was found by the Mallory group to have negligible solubility. Currently the longest known [n]phenacene is an phenacene derivative that was synthesized by the Mallory group with tert-butyl substituents acting as solubilizing groups, but it was found to have only modest solubility. The goal of my research is the synthesis of the phenacene derivatives shown below. My previous attempted synthesis of an  phenacene with two long-chain alkyl groups proved difficult in the last step of the synthesis due to solubility issues. In the anticipation that four long-chain alkyl groups would increase the solubility, the synthesis of the  phenacene with four solubilizing groups was initiated. Unfortunately, the second to last reaction in its synthesis did not seem to be successful for unknown reasons; however, the department has now acquired a UV detector for the LCMS that should allow verification of the precursor of the phenacene derivative with a hydrogen in the place of R2, and a technique for tracking the last reaction in a way that is more precise than NMR spectroscopy. The purpose of my research this summer is to synthesize the precursors to the  phenacene derivatives shown below and verify their identity using the LCMS and from there, attempt the photocyclization reactions to give the  phenacene derivatives themselves.
The planned syntheses of these compounds involve a sequence of different types of chemical reactions, including Grignard, Friedel-Crafts, bromination, Arbuzov, Horner-Wadsworth-Emmons, and photocyclization reactions