Graphene based electrodes have need for improvement in their chemical capacitance. Recent density functional theory calculations have shown that the capacitance can be improved via structural and morphological features of the electrode. The structure of the organic compounds known as benzofulvenes may act as a model for graphene. Rotation about the exocyclic double bond of benzofulvenes may change the conjugation of the overall molecule. We have observed that an increased dihedral angle reduces overall conjugation of the molecule as seen from NMR, and crystal structure analysis. The dihedral angle was probed using crystal structure analysis, and shift change in 1H NMR. Using an olefination reaction we were able to synthesize various benzofulvenes using 3-phenyl-1H-indene, 1,8-Diazabicycloundec-7-ene (DBU), and 2-methyl tetrahydrofuran (2-MeTHF). Reactions were performed within a microwave reactor at 60 °C for 10 minutes. By attaching different substituents to the ortho- and meta- position adjacent to the exoyclic double bond of benzofulvenes we were able alter the dihedral angle. Overall, 9 benzofulvenes have been synthesized with substituents that include, halogens, sterically bulky aliphatic groups, along with benzofulvene dimers. Both 13C and 1H NMR, and GC/MS were used to confirm the identify of our benzofulvenes. Our aim was to increase the steric hindrance around the exocyclic double bond in order to gradually step up the dihedral angle. With this information on the rotation of the exocyclic double bond's effect on conjugation in benzofulvenes we could further help improving chemical capacitance on graphene based electrodes.

Rotation of benzofulvenes' exocyclic double bond and its effects on molecular conjugation

253rd National Meeting (2017)

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