title: Divergent Coordination Chemistry: Parallel Synthesis of [2×2] Iron(II) Grid-Complex Tauto-Conformers.
abstract: The coordination of iron(II) ions by a homoditopic ligand L with two tridentate chelates leads to the tautomerism-driven emergence of complexity, with isomeric tetramers and trimers as the coordination products. The structures of the two dominant [Fe(II) 4 L4 ](8+) complexes were determined by X-ray diffraction, and the distinctness of the products was confirmed by ion-mobility mass spectrometry. Moreover, these two isomers display contrasting magnetic properties (Fe(II) spin crossover vs. a blocked Fe(II) high-spin state). These results demonstrate how the coordination of a metal ion to a ligand that can undergo tautomerization can increase, at a higher hierarchical level, complexity, here expressed by the formation of isomeric molecular assemblies with distinct physical properties. Such results are of importance for improving our understanding of the emergence of complexity in chemistry and biology.
authors.affiliation: Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schäfer
authors.affiliation: Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Greisch
authors.affiliation: Fachbereich Physik, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Strasse 46, 67663, Kaiserslautern, Germany.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Faus
authors.affiliation: Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
authors.forename: Tilmann
authors.initials: T
authors.lastname: Bodenstein
authors.affiliation: Institute of Inorganic Chemistry, Technology and Materials, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, 81237, Slovak Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Šalitroš
authors.affiliation: Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.|Karlsruhe Nano-Micro Facility (KNMF), Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Fuhr
authors.affiliation: Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Fink
authors.affiliation: Fachbereich Physik, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Strasse 46, 67663, Kaiserslautern, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Schünemann
authors.affiliation: Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.|Institut für Physikalische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 2, 76131, Karlsruhe, Germany.
authors.forename: Manfred M
authors.initials: MM
authors.lastname: Kappes
authors.affiliation: Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany. Mario.Ruben@kit.edu.|Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg, 23, rue du Loess, BP 43, 67034, Strasbourg cedex 2, France. Mario.Ruben@kit.edu.
authors.forename: Mario
authors.initials: M
authors.lastname: Ruben
keywords: X-ray diffraction; divergent coordination chemistry; iron complexes; magnetic properties; spin crossover