Self-assembly of discotic liquid crystal porphyrin into more controllable ordered nanostructure mediated by fluorophobic effect

Abstract

The novel nanoscale discotic liquid crystal porphyrin with partial chain perfluorination, which has the same basic structure as the best photoreceptor in nature (chlorophyll), shows an exceptionally enhanced tendency to self-assemble into ordered nanostructure. Defect-free homeotropically aligned fluorinated porphyrin thin films were, for the first time, fabricated and characterised. The ability to self-assemble large π-conjugated discotic molecules into highly ordered nanostructure via partial chain perfluorination provides new insight for the bottom-up nanofabrication of molecular devices. The controllable ordered porphyrin nanostructure with directed molecular arrangement holds great promise for use in high-performance electronic devices.

Keywords:

• partially perfluoroalkylated liquid crystal porphyrin
• self-assembly
• ordered nanostructure
• uniform alignment
• defect-free homeotropically aligned porphyrin thin films

Acknowledgements

This work is supported, in part, by Ohio Board of Regents' Research Challenge award, National Science Foundation grant DMR-07-06290. Use of the Advanced Photon Source (APS) was supported by the U.S. Department of Energy (DOE), Basic Energy Sciences (BES), Office of Science, under Contract No. W-31-109-Eng-38. The Midwestern Universities Collaborative Access Team's (MUCAT) sector at the APS is supported by the U.S. DOE, BES, Office of Science, through the Ames Laboratory under Contract No. W-7405-Eng-82. We gratefully thank Dr. O. Lavrentovich for the use of their characterisation equipment.