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Self-Assembly of Dendronized Perylene Bisimides into Complex Helical Columns

Published

Author(s)

Virgil Percec, Mihai Peterca, Timur Tadjiev, Xiangbing Zeng, Goran Ungar, Pawaret Leowanawat, Emad Aqad, Mohammad Imam, Brad Rosen, Umit Akbey, Robert Graf, Sivakumar Sekharan, Daniel Sebastiani, Hans -. Spiess, Paul A. Heiney, Steven Hudson

Abstract

The synthesis of perylene 3,4:9,10-tetracarboxylic acid bisimides (PBIs) dendronized with first generation dendrons containing 0 to 4 methylenic units (m) between the imide group and the dendron, (3,4,5)12G1-m-PBI, is reported. Structural analysis of their self-organized arrays by DSC, Xray diffraction, molecular modeling and solid state 1H-NMR was carried out on oriented samples with heating and cooling rates of 20 to 0.2 °C/min. At high temperature (3,4,5)12G1-m-PBI self-assemble into 2D- hexagonal columnar phases with intracolumnar order. At low temperature they form orthorhombic (m = 0, 2, 3, 4) and monoclinic (m = 1) columnar arrays with 3D periodicity. The orthorhombic phase has symmetry close to hexagonal. For m = 0, 2, 3, 4 they consist of tetramers as basic units. The tetramers contain a pair of two molecules arranged side by side and another pair in the next stratum of the column, turned upside-down and rotated around the column axis at different angles for different m. In contrast, for m = 1 there is only one molecule in each stratum, with a four-strata 21 helical repeat. All molecules face up in one column, and down in the second column of the monoclinic cell. This allows close and extended π-stacking, unlike in the disruptive up-down alteration from the case of m = 0, 2, 3, 4. Most of the 3D structures were observed only by cooling at rates of 1 °C/min or less. This complex helical self-assembly is representative for other classes of dendronized PBIs investigated for organic electronics and solar cells.
Citation
Journal of the American Chemical Society
Volume
133
Issue
31

Keywords

organic electronics, self assembly, photovoltaics

Citation

Percec, V. , Peterca, M. , Tadjiev, T. , Zeng, X. , Ungar, G. , Leowanawat, P. , Aqad, E. , Imam, M. , Rosen, B. , Akbey, U. , Graf, R. , Sekharan, S. , Sebastiani, D. , Spiess, H. , Heiney, P. and Hudson, S. (2011), Self-Assembly of Dendronized Perylene Bisimides into Complex Helical Columns, Journal of the American Chemical Society, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=908817 (Accessed April 17, 2024)
Created June 23, 2011, Updated October 12, 2021