title: Superchiral Pd3 L6 Coordination Complex and Its Reversible Structural Conversion into Pd3 L3 Cl6 Metallocycles.
abstract: Large, non-symmetrical, inherently chiral bispyridyl ligand L derived from natural ursodeoxycholic bile acid was used for square-planar coordination of tetravalent Pd(II) , yielding the cationic single enantiomer of superchiral coordination complex 1 Pd3 L6 containing 60 well-defined chiral centers in its flower-like structure. Complex 1 can readily be transformed by addition of chloride into a smaller enantiomerically pure cyclic trimer 2 Pd3 L3 Cl6 containing 30 chiral centers. This transformation is reversible and can be restored by the addition of silver cations. Furthermore, a mixture of two constitutional isomers of trimer, 2 and 2', and dimer, 3 and 3', can be obtained directly from L by its coordination to trans- or cis-N-pyridyl-coordinating Pd(II) . These intriguing, water-resistant, stable supramolecular assemblies have been thoroughly described by (1) H DOSY NMR, mass spectrometry, circular dichroism, molecular modelling, and drift tube ion-mobility mass spectrometry.
authors.affiliation: University of Jyvaskyla, Department of Chemistry, Nanoscience Center, P.O. Box 35, 40014 University of Jyvaskyla (Finland). jurcekondrej@gmail.com.
authors.forename: Ondřej
authors.initials: O
authors.lastname: Jurček
authors.affiliation: University of Jyvaskyla, Department of Chemistry, Nanoscience Center, P.O. Box 35, 40014 University of Jyvaskyla (Finland).
authors.forename: Pia
authors.initials: P
authors.lastname: Bonakdarzadeh
authors.affiliation: University of Jyvaskyla, Department of Chemistry, Nanoscience Center, P.O. Box 35, 40014 University of Jyvaskyla (Finland). elina.o.kalenius@jyu.fi.
authors.forename: Elina
authors.initials: E
authors.lastname: Kalenius
authors.affiliation: University of Tartu, Institute of Physics, Ravila 14c, 50411 Tartu (Estonia).
authors.forename: Juha Matti
authors.initials: JM
authors.lastname: Linnanto
authors.affiliation: Tofwerk AG, Uttigenstrasse 22, 3600 Thun (Switzerland).
authors.forename: Michael
authors.initials: M
authors.lastname: Groessl
authors.affiliation: Tofwerk AG, Uttigenstrasse 22, 3600 Thun (Switzerland).
authors.forename: Richard
authors.initials: R
authors.lastname: Knochenmuss
authors.affiliation: University of Jyvaskyla, Nanoscience Center, Department of Biological and Environmental Science, P.O. Box 35, 40014 University of Jyvaskyla (Finland).
authors.forename: Janne A
authors.initials: JA
authors.lastname: Ihalainen
authors.affiliation: University of Jyvaskyla, Department of Chemistry, Nanoscience Center, P.O. Box 35, 40014 University of Jyvaskyla (Finland). kari.t.rissanen@jyu.fi.
authors.forename: Kari
authors.initials: K
authors.lastname: Rissanen
keywords: bile acid; chirality; metallocycle; self-assembly; supramolecular chemistry