title: Self-assembly of metallosupramolecular rhombi from chiral concave 9,9'-spirobifluorene-derived bis(pyridine) ligands.
abstract: Two new 9,9'-spirobifluorene-based bis(4-pyridines) were synthesised in enantiopure and one also in racemic form. These ligands act as concave templates and form metallosupramolecular [(dppp)2M2L2] rhombi with cis-protected [(dppp)Pd](2+) and [(dppp)Pt](2+) ions. The self-assembly process of the racemic ligand preferably occurs in a narcissistic self-recognising manner. Hence, a mixture of all three possible stereoisomers [(dppp)2M2{(R)-L}2](OTf)4, [(dppp)2M2{(S)-L}2](OTf)4, and [(dppp)2M2{(R)-L}{(S)-L}](OTf)4 was obtained in an approximate 1.5:1.5:1 ratio which corresponds to an amplification of the homochiral assemblies by a factor of approximately three as evidenced by NMR spectroscopy and mass spectrometry. The racemic homochiral assemblies could also be characterised by single crystal X-ray diffraction.
authors.affiliation: University of Bonn, Kekulé-Institute of Organic Chemistry and Biochemistry, Gerhard-Domagk-Str. 1, D-53121 Bonn, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Hovorka
authors.affiliation: University of Bonn, Kekulé-Institute of Organic Chemistry and Biochemistry, Gerhard-Domagk-Str. 1, D-53121 Bonn, Germany.
authors.forename: Sophie
authors.initials: S
authors.lastname: Hytteballe
authors.affiliation: University of Bonn, Kekulé-Institute of Organic Chemistry and Biochemistry, Gerhard-Domagk-Str. 1, D-53121 Bonn, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Piehler
authors.affiliation: University of Bonn, Kekulé-Institute of Organic Chemistry and Biochemistry, Gerhard-Domagk-Str. 1, D-53121 Bonn, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Meyer-Eppler
authors.affiliation: Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland.
authors.forename: Filip
authors.initials: F
authors.lastname: Topić
authors.affiliation: Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland.
authors.forename: Kari
authors.initials: K
authors.lastname: Rissanen
authors.affiliation: University of Bonn, Kekulé-Institute of Organic Chemistry and Biochemistry, Gerhard-Domagk-Str. 1, D-53121 Bonn, Germany.
authors.forename: Marianne
authors.initials: M
authors.lastname: Engeser
authors.affiliation: University of Bonn, Kekulé-Institute of Organic Chemistry and Biochemistry, Gerhard-Domagk-Str. 1, D-53121 Bonn, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Lützen
keywords: 9,9’-spirobifluorene; concave templates; metal complexes; self-assembly; self-sorting; supramolecular chemistry