Syntheses of [n]Phenacenes

Posted May 13th, 2010 at 3:08 pm.

Kate Butler
and
Amber Hopkins

Mentor: Dr. Frank Mallory

[n]Phenacenes are compounds that contain n benzene rings fused together in a zigzag pattern. An example of a [7]phenacene derivative is shown below.

alkyl_group_hopkins

R=alkyl group

The synthesis of [n]phenacenes is of particular importance for the investigation of whether pseudo one-dimensional versions of the pseudo two-dimensional graphite sheets possess similar patterns of conductivity to the graphite sheets. Previously, an [n]phenacene having 11 fused rings has been synthesized by the Mallory group. [n]Phenacenes with n > 6 are extremely insoluble, so to produce larger [n]phenacenes by chemical synthesis, solubilizing groups (R) must be attached. [n]Phenacenes with n > 11 have been attempted, but have proved unsuccessful due to issues of solubility based on the various R-groups used.

The most recently concluded study tested a branched 12-carbon chain and a straight 12-carbon chain as solubilizing groups, both of which proved to make the phenacene product too soluble. Currently, solubilizing groups of shorter carbon chains are the focus of our investigation in hopes of obtaining correct solubility. Two possible schemes contain 8-carbons each, one straight chain and one branched chain.

Using synthesis schemes beginning from 1-bromobutane and 1-bromooctane, a sequence of reactions will be explored in the attempted syntheses of [7]phenacene and [15]phenacene derivatives.

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