title: Enantioselective assembly of a ruthenium(II) polypyridyl complex into a double helix.
abstract: Evolution can increase the complexity of matter by self-organization into helical architectures, the best example being the DNA double helix. One common aspect, apparently shared by most of these architectures, is the presence of covalent bonds within the helix backbone. Here, we report the unprecedented crystal structures of a metal complex that self-organizes into a continuous double helical structure, assembled by non-covalent building blocks. Built up solely by weak stacking interactions, this alternating tread stairs-like double helical assembly mimics the DNA double helix structure. Starting from a racemic mixture in aqueous solution, the ruthenium(II) polypyridyl complex forms two polymorphic structures of a left-handed double helical assembly of only the Λ-enantiomer. The stacking of the helices is different in both polymorphs: a crossed woodpile structure versus a parallel columnar stacking.
authors.affiliation: Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent (Belgium). Kristof.VanHecke@UGent.be.
authors.forename: Kristof
authors.initials: K
authors.lastname: Van Hecke
authors.forename: Thomas
authors.initials: T
authors.lastname: Cardinaels
authors.forename: Peter
authors.initials: P
authors.lastname: Nockemann
authors.forename: Jeroen
authors.initials: J
authors.lastname: Jacobs
authors.forename: Louis
authors.initials: L
authors.lastname: Vanpraet
authors.forename: Tatjana N
authors.initials: TN
authors.lastname: Parac-Vogt
authors.forename: Rik
authors.initials: R
authors.lastname: Van Deun
authors.forename: Koen
authors.initials: K
authors.lastname: Binnemans
authors.forename: Luc
authors.initials: L
authors.lastname: Van Meervelt
mesh_terms: D003460:Crystallization; D008958:Models, Molecular; D011725:Pyridines / Q000737:chemistry*; D017975:Ruthenium Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D011725:Pyridines; D017975:Ruthenium Compounds
keywords: double helix; enantiomer; polypyridyl; ruthenium; self-assembly