title: Torands Revisited: Metal Sequestration and Self-Assembly of Cyclo-2,9-tris-1,10-phenanthroline Hexaaza Macrocycles.
abstract: A series of novel toroidal cyclo-2,9-tris-1,10-phenanthroline macrocycles with an unusual hexaaza cavity are reported. Nickel-mediated Yamamoto aryl-aryl coupling was found to be a versatile tool for the cyclotrimerization of functionalized 1,10-phenathroline precursors. Due to the now improved processability, both liquid-crystalline behavior in the bulk phase and two-dimensional self-assembly at the molecular level could be studied, for the first time, for a torand system. The macrocycles exhibited a strong affinity for the complexation of different metal cations, as evidenced by MALDI-TOF analysis and spectroscopic methods. Experimental results were correlated to an extensive computational study of the cyclo-2,9-tris-1,10-phenanthroline cavity and its binding mode for metal cations. Due to the combination of several interesting features, toroidal macrocycles may find future applications in the field of ion and charge transport through molecular channels, as well as for chemical sensing and molecular writing in surface-confined monolayers under STM conditions.
authors: Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany).|Present Address: BASF SE, Carl-Bosch-Straße 38, 67056 Ludwigshafen (Germany).
authors: Matthias Georg
authors: MG
authors: Schwab
authors: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 (Japan).
authors: Masayoshi
authors: M
authors: Takase
authors: Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany).
authors: Alexey
authors: A
authors: Mavrinsky
authors: Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany).
authors: Wojciech
authors: W
authors: Pisula
authors: Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany).
authors: Xinliang
authors: X
authors: Feng
authors: Institute of Technical and Macromolecular Chemistry, Division of Technical Chemistry and Petrol Chemistry, RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany).
authors: José A
authors: JA
authors: Gámez
authors: Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim (Germany).
authors: Walter
authors: W
authors: Thiel
authors: Katholieke Universiteit Leuven, Celestijnenlaan 200 F, 3001 Leuven (Belgium).
authors: Kunal S
authors: KS
authors: Mali
authors: Katholieke Universiteit Leuven, Celestijnenlaan 200 F, 3001 Leuven (Belgium).
authors: Steven
authors: S
authors: de Feyter
authors: Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz (Germany). muellen@mpip-mainz.mpg.de.
authors: Klaus
authors: K
authors: Müllen
keywords: liquid crystals; macrocycles; phenanthrolines; scanning probe microscopy; self-assembly