title: Shape-persistant macrocycles with terpyridine units: synthesis, characterization, and structure in the crystal.
abstract: The synthesis of a variety of shape-persistent macrocycles with either one (1a-d, 2) or two (opposing) terpyridine units (3, 4, 5a-c) and inner diameters of up to 2 nm is described. The sequences are mainly based on transition metal cross-coupling reactions and, whenever appropriate, compared with one another regarding their respective efficiency. Typical overall yields and amounts prepared range from 8% (4) to 27% (3) and 25 mg (1a) to 290 mg (1b), respectively. For solubility and processing of the targeted cycles, all precursors have already been decorated with flexible side chains (hexyloxy or hexyloxymethyl). The cycles' characterization is based on MALDI-TOF mass spectrometry, 2D NMR spectroscopy, and/or low-temperature single-crystal X-ray diffraction. Their packing in the crystal is discussed in terms of both number and length of side chains. Cycle 1d was physisorbed into an ordered structure at the solution-HOPG interface and investigated by scanning tunneling microscopy (STM).
authors.affiliation: Institut für Chemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Grave
authors.forename: Dieter
authors.initials: D
authors.lastname: Lentz
authors.forename: Andreas
authors.initials: A
authors.lastname: Schäfer
authors.forename: Paolo
authors.initials: P
authors.lastname: Samorì
authors.forename: Jürgen P
authors.initials: JP
authors.lastname: Rabe
authors.forename: Peter
authors.initials: P
authors.lastname: Franke
authors.forename: A Dieter
authors.initials: AD
authors.lastname: Schlüter