title: Fast Oxidative Cyclooligomerization towards Low- and High-Symmetry Thiophene Macrocycles.
abstract: Macrocycles with quaterthiophene subunits were obtained by cyclooligomerization by direct oxidative coupling of unsubstituted dithiophene moieties. The rings were closed with high selectivity by an α,β'-connection of the thiophenes as proven by NMR spectroscopy. The reaction of the precursor with terthiophene moieties yielded the symmetric α,α'-linked macrocycle in low yield together with various differently connected isomers. Blocking of the β-position of the half-rings yielded selectively the α,α'-linked macrocycle. Selected cyclothiophenes were investigated by scanning tunneling microscopy, which displayed the formation of highly ordered 2D crystalline monolayers.
authors.affiliation: Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany), Fax.
authors.forename: Stefan K
authors.initials: SK
authors.lastname: Maier
authors.affiliation: Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany), Fax.
authors.forename: Georgiy
authors.initials: G
authors.lastname: Poluektov
authors.affiliation: Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany), Fax. stefan.jester@uni-bonn.de.
authors.forename: Stefan-S
authors.initials: SS
authors.lastname: Jester
authors.affiliation: Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, 14476, Golm, Germany), Fax. Heiko.Moeller@uni-potsdam.de.
authors.forename: Heiko M
authors.initials: HM
authors.lastname: Möller
authors.affiliation: Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany), Fax. hoeger@uni-bonn.de.
authors.forename: Sigurd
authors.initials: S
authors.lastname: Höger
keywords: cyclooligomers; scanning tunneling microscopy; self-assembled monolayers; shape-persistent macrocycles; thiophenes