Nanoribbons or weakly connected acenes? The influence of pyrene insertion on linearly extended ring systems
- University of Kentucky, Lexington, KY (United States)
Derived from the lateral fusion of benzene rings, acenes are a class of π-conjugated molecules containing a single aromatic sextet, where system size is inversely correlated with chemical stability. In the pursuit of creating graphene nanoribbons/nanowires, several extended-ring structures have been synthesized through linear combinations of azaacenes and pyrene. Importantly, these extended systems demonstrate enhanced chemical stability and allow for the construction of macromolecular-sized structures. In this report we present a combined quantum-chemical and experimental study to reveal the cost of these improved characteristics in fully carbon-based systems. The results clearly show that pyrene moieties inserted among acene units do not result in long acene-like structures, rather the pyrene-inserted acene is, electronically, a series of (nearly) isolated acenes. The origin of pyrene's electronic blocking effect and implications on oxidized and photoexcited states of these extended-ring systems are detailed. The results of this investigation definitively show that coupling pyrene in an orthogonal orientation (through the 4, 5/9, 10 positions or e/l faces) to acenes should be eschewed if nanographene-/nanowire-like structures are desired.
- Research Organization:
- University of Kentucky, Lexington, KY (United States)
- Sponsoring Organization:
- Office of Naval Research (ONR); USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES)
- OSTI ID:
- 1982230
- Journal Information:
- Journal of Materials Chemistry C, Journal Name: Journal of Materials Chemistry C Journal Issue: 47 Vol. 9; ISSN 2050-7526
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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