Star-shaped oligo(p-phenylenevinylene) substituted hexaarylbenzene: purity, stability, and chiral self-assembly.
An oligo(p-phenylenevinylene) (OPV)-substituted hexaarylbenzene has been synthesized and fully characterized. Recycling gel permeation chromatography appeared to be a powerful technique to obtain the OPV molecules in a very pure form. X-ray analysis and polarization optical microscopy revealed that the OPV molecule is plastic crystalline at room temperature with an ordered columnar superstructure. In apolar solvents, the molecules self-assemble via a highly cooperative fashion into right-handed chiral superstructures, which are stable even at high temperatures and low concentration. Atomic force microscopy revealed right-handed fibers with a diameter of 6 nm, indicating pi-stacked aggregates; on a silicon oxide substrate, supercoiled chiral structures were observed. STM studies on a liquid-solid interface showed that the star-shaped OPV molecule forms an organized monolayer having a chiral hexagonal lattice.
Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Zeljko
Z
Tomović
Joost
J
van Dongen
Subi J
SJ
George
Hong
H
Xu
Wojciech
W
Pisula
Philippe
P
Leclère
Maarten M J
MM
Smulders
Steven
S
De Feyter
E W
EW
Meijer
Albertus P H J
AP
Schenning