title: An Octanuclear Metallosupramolecular Cage Designed To Exhibit Spin-Crossover Behavior.
abstract: By employing the subcomponent self-assembly approach utilizing 5,10,15,20-tetrakis(4-aminophenyl)porphyrin or its zinc(II) complex, 1H-4-imidazolecarbaldehyde, and either zinc(II) or iron(II) salts, we were able to prepare O-symmetric cages having a confined volume of ca. 1300 Å3. The use of iron(II) salts yielded coordination cages in the high-spin state at room temperature, manifesting spin-crossover in solution at low temperatures, whereas corresponding zinc(II) salts led to the corresponding diamagnetic analogues. The new cages were characterized by synchrotron X-ray crystallography, high-resolution mass spectrometry, and NMR, Mössbauer, IR, and UV/Vis spectroscopy. The cage structures and UV/Vis spectra were independently confirmed by state-of-the-art DFT calculations. A remarkably high-spin-stabilizing effect through encapsulation of C70was observed. The spin-transition temperature T1/2is lowered by 20 K in the host-guest complex.
authors.affiliation: Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany.
authors.forename: Niklas
authors.initials: N
authors.lastname: Struch
authors.affiliation: Mulliken Center for Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Beringstrasse 4, 53115, Bonn, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Bannwarth
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
authors.forename: Tanya K
authors.initials: TK
authors.lastname: Ronson
authors.affiliation: Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Lorenz
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Mienert
authors.affiliation: Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Wagner
authors.affiliation: Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany.
authors.forename: Marianne
authors.initials: M
authors.lastname: Engeser
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany.
authors.forename: Eckhard
authors.initials: E
authors.lastname: Bill
authors.affiliation: University of Jyvaskyla, Department of Chemistry, Nanoscience Center, P.O. Box 34, 40014, Jyvaskyla, Finland.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Puttreddy
authors.affiliation: University of Jyvaskyla, Department of Chemistry, Nanoscience Center, P.O. Box 34, 40014, Jyvaskyla, Finland.
authors.forename: Kari
authors.initials: K
authors.lastname: Rissanen
authors.affiliation: Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Beck
authors.affiliation: Mulliken Center for Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Beringstrasse 4, 53115, Bonn, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Grimme
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Nitschke
authors.affiliation: Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Lützen
keywords: host-guest systems; iron(II) complexes; metallosupramolecular chemistry; self-assembly; spin crossover