title: Ligand Aspect Ratio as a Decisive Factor for the Self-Assembly of Coordination Cages.
abstract: It is possible to control the geometry and the composition of metallasupramolecular assemblies via the aspect ratio of their ligands. This point is demonstrated for a series of iron- and palladium-based coordination cages. Functionalized clathrochelate complexes with variable aspect ratios were used as rod-like metalloligands. A cubic Fe(II)8L12 cage was obtained from a metalloligand with an intermediate aspect ratio. By increasing the length or by decreasing the width of the ligand, the self-assembly process resulted in the clean formation of tetrahedral Fe(II)4L6 cages instead of cubic cages. In a related fashion, it was possible to control the geometry of Pd(II)-based coordination cages. A metalloligand with a large aspect ratio gave an entropically favored tetrahedral Pd(II)4L8 assembly, whereas an octahedral Pd(II)6L12 cage was formed with a ligand of the same length but with an increased width. The aspect ratio can also be used to control the composition of dynamic mixtures of Pd(II) cages. Out of two metalloligands with only marginally different aspect ratios, one gave rise to a self-sorted collection of Pd(II)4L8 and Pd(II)6L12 cages, whereas the other did not.
authors: Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors: Suzanne M
authors: SM
authors: Jansze
authors: Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors: Giacomo
authors: G
authors: Cecot
authors: Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors: Matthew D
authors: MD
authors: Wise
authors: Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors: Konstantin O
authors: KO
authors: Zhurov
authors: Department of Chemistry, University of Cambridge , Cambridge CB2 1EW, United Kingdom.
authors: Tanya K
authors: TK
authors: Ronson
authors: Department of Chemistry, University of Cambridge , Cambridge CB2 1EW, United Kingdom.
authors: Ana M
authors: AM
authors: Castilla
authors: Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors: Alba
authors: A
authors: Finelli
authors: Laboratory of Crystallography, Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.|Swiss-Norwegian Beamline, ESRF , 38000 Grenoble, France.
authors: Philip
authors: P
authors: Pattison
authors: Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors: Euro
authors: E
authors: Solari
authors: Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors: Rosario
authors: R
authors: Scopelliti
authors: Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences , 119991 Moscow, Russia.
authors: Genrikh E
authors: GE
authors: Zelinskii
authors: Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences , 119991 Moscow, Russia.
authors: Anna V
authors: AV
authors: Vologzhanina
authors: Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences , 119991 Moscow, Russia.
authors: Yan Z
authors: YZ
authors: Voloshin
authors: Department of Chemistry, University of Cambridge , Cambridge CB2 1EW, United Kingdom.
authors: Jonathan R
authors: JR
authors: Nitschke
authors: Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors: Kay
authors: K
authors: Severin