Presenter(s): Cyrus Waters − Biochemistry
Faculty Mentor(s): Ramesh Jasti, Brittany White
Poster 20
Research Area: Organic Chemistry
Funding: SAACS Summer Research Award
Cycloparaphenylenes (CPPs) have size-dependent optoelectronic properties: the HOMO/LUMO gap size increases as benzene subunits are added. This capacity to tune the band gap makes CPPs attractive for use in organic electronic devices. Similarly, pentacene shows promise as a component of photovoltaic cells because of its uniquely high capacity for singlet fission (SF), whereby one high-energy incident photon is harnessed to yield two lower-energy triplets. In devices sensitized to SF, two electrons can be pushed per photon, bypassing the Shockley-Queisser efficiency limit and doubling the photocurrent from specific wavelengths of absorbed light relative to traditional, silicon-based photovoltaics. Pentacene-incorporated CPPs combine the two structures in a fully-conjugated system, potentially allowing the size of the CPP to control the energy of light at which the pentacene undergoes SF. Here, the synthesis of 6,13-pentacene-incorporated [10]cycloparaphenylene was attempted. Suzuki coupling of selectively-linked curved precursors yielded a strained macrocyclic intermediate. Attempts at reductive aromatization of the macrocycle have successfully aromatized the CPP backbone but have failed to aromatize the pentacene unit, instead yielding either the insufficiently reduced diol or its overly reduced dihydrogen analogue.