title: Optically pure, monodisperse cis-oligodiacetylenes: aggregation- induced chirality enhancement.
abstract: Conformational changes in the conjugated backbone of poly- and oligodiacetylenes (PDAs and ODAs) play an important role in determining the electronic properties of these compounds. At the same time, conformational changes can also result in a folded structure that shows helical chirality. Using d-camphor as a chiral building block, we have designed a high-yielding, iterative synthesis of monodisperse, optically pure cis-oligodiacetylenes (ODAs). cis-ODAs up to the tridecamer have been formed, which is the longest monodisperse cis-ODA reported to date. UV/Vis spectroscopy suggests a large effective conjugation length in THF, likely the result of a linear, planar conformation in this solvent. High-resolution STM/AFM measurements of the nonamer cast from THF onto HOPG show a linear structure. In iPrOH, circular dichroism (CD) spectra suggest the formation of chiral aggregates for ODAs with at least nine d-camphor units, based on a strong CD response.
authors.forename: Erin T
authors.initials: ET
authors.lastname: Chernick
authors.forename: Gabor
authors.initials: G
authors.lastname: Börzsönyi
authors.forename: Christian
authors.initials: C
authors.lastname: Steiner
authors.forename: Maximilian
authors.initials: M
authors.lastname: Ammon
authors.forename: David
authors.initials: D
authors.lastname: Gessner
authors.forename: Sabine
authors.initials: S
authors.lastname: Frühbeisser
authors.forename: Franziska
authors.initials: F
authors.lastname: Gröhn
authors.forename: Sabine
authors.initials: S
authors.lastname: Maier
authors.forename: Rik R
authors.initials: RR
authors.lastname: Tykwinski