Abstract
The self-assembly and solid-state semiconducting properties of single crystals of a trisradical tricationic complex composed of the diradical dicationic cyclobis(paraquat-p-phenylene) (CBPQT2(•+)) ring and methyl viologen radical cation (MV•+) are reported. An organic field effect transistor incorporating single crystals of the CBPQT 2(•+)⊂MV•+ complex was constructed using lithographic techniques on a silicon substrate and shown to exhibit p-type semiconductivity with a mobility of 0.05 cm2 V-1 s -1. The morphology of the crystals on the silicon substrate was characterized using scanning electron microscopy which revealed that the complexes self-assemble into "molecular wires" observable by the naked-eye as millimeter long crystalline needles. The nature of the recognition processes driving this self-assembly, radical-radical interactions between bipyridinium radical cations (BIPY•+), was further investigated by resonance Raman spectroscopy in conjunction with theoretical investigations of the vibrational modes, and was supported by X-ray structural analyses of the complex and its free components in both their radical cationic and dicationic redox states. These spectroscopic investigations demonstrate that the bond order of the BIPY•+ radical cationic units of host and guest components is not changed upon complexation, an observation which relates to its conductivity in the solid-state. We envision the modularity inherent in this kind of host-guest complexation could be harnessed to construct a library of custom-made electronic organic materials tailored to fit the specific needs of a given electronic application.
Original language | English (US) |
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Pages (from-to) | 9964-9971 |
Number of pages | 8 |
Journal | ACS nano |
Volume | 6 |
Issue number | 11 |
DOIs | |
State | Published - Nov 27 2012 |
Keywords
- Raman spectroscopy
- electrochemistry
- molecular electronics
- organic field effect transistors
- quantum mechanics
ASJC Scopus subject areas
- Materials Science(all)
- Engineering(all)
- Physics and Astronomy(all)