title: Chiral Supramolecular Gels with Lanthanide Ions: Correlation between Luminescence and Helical Pitch.
abstract: We report the correlation between the fluorescence intensity and the helical pitch of supramolecular hydrogels with Tb(III) and Eu(III) as well as their inkjet printing patterning as an application. The luminescent gels, which exhibited three different emissions of red, green, and blue, could be prepared without and with Eu(III) and Tb(III). The luminescence intensity of supramolecular gels (gel-Tb and gel-Eu) composed of Tb(III) and Eu(III) was ca. 3-fold larger than that of the sol (1+Tb(III) or 1+Eu(III)), which was attributed to large tilting angles between molecules. By AFM observations, these gels showed well-defined right-handed helical nanofibers formed by coordination bonds in which the helical pitch lengths were strongly dependent on the concentrations of lanthanide ions. In particular, the large luminescence intensity of gel-Tb exhibited a smaller helical pitch length than that of gel-1 due to relatively weak π-π stacking with large tilting angles between molecules. The luminescence intensities were enhanced linearly with increasing concentrations of lanthanide ions. This is the first example of the correlation between the helical pitch length and the luminescence intensity of supramolecular materials. The coordination bonding in supramolecular hydrogels had a strong influence on rheological properties. We also developed a water-compatible inkjet printing system to generate luminescent supramolecular gels on A4-sized paper. The images of a logo and the text were composed of three different emissions and were well-printed on A4 sized paper coated with gel-1.
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences Gyeongsang National University , Jinju 660-701, Korea.
authors.forename: Chaelin
authors.initials: C
authors.lastname: Kim
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences Gyeongsang National University , Jinju 660-701, Korea.
authors.forename: Ka Young
authors.initials: KY
authors.lastname: Kim
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences Gyeongsang National University , Jinju 660-701, Korea.|Department of Chemistry, Kitakyushu University , Kitakyushu 819-0395, Japan.
authors.forename: Ji Ha
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences Gyeongsang National University , Jinju 660-701, Korea.
authors.forename: Junho
authors.initials: J
authors.lastname: Ahn
authors.affiliation: Department of Chemistry, Kitakyushu University , Kitakyushu 819-0395, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Sakurai
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences Gyeongsang National University , Jinju 660-701, Korea.
authors.forename: Shim Sung
authors.identifier: http://orcid.org/0000-0002-4638-5466
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Research Institute of Natural Sciences Gyeongsang National University , Jinju 660-701, Korea.
authors.forename: Jong Hwa
authors.identifier: http://orcid.org/0000-0002-8936-2272
authors.initials: JH
authors.lastname: Jung
keywords: helical pitch; inkjet printing; lanthanide ion; luminescence; supramolecular gel