Search

Inspiration for molecular design and construction can be derived from mathematically based structures. In the quest for new materials, the adaptation of new building blocks can lead to unexpected results. Towards these ends, the quantitative single-step self-assembly of a shape-persistent, Archimedean-based building block, which generates the largest molecular sphere (a cuboctahedron) that has been unequivocally characterized by synchrotron X-ray analysis, is described. The unique properties of this new construct give rise to a dilution-based transformation into two identical spheres (octahedra) each possessing one half of the molecular weight of the parent structure; concentration of this octahedron reconstitutes the original cuboctahedron. These chemical phenomena are reminiscent of biological fission and fusion processes. The large 6 nm cage structure was further analyzed by 1D and 2D NMR spectroscopy, mass spectrometry, and collision cross-section analysis. New routes to molecular encapsulation can be envisioned. [ABSTRACT FROM AUTHOR]

A facile high yield, self-assembly process that leads to a terpyridine-based, three-dimensional, bis-rhomboidal-shaped, molecular wheel is reported. The desired coordination-driven supramolecular wheel involves eight structurally distorted tristerpyridine (tpy) ligands possessing a 60° angle between the adjacent tpy units and twelve Zn2+ ions. The tpy ligand plays dual roles in the self-assembly process: two are staggered at 180° to create the internal hub, while six produce the external rim. The wheel can be readily generated by mixing the tpy ligand and Zn2+ in a stoichiometric ratio of 2:3; full characterization is provided by ESI-MS, NMR spectroscopy, and TEM imaging. [ABSTRACT FROM AUTHOR]

Wo ein Rad ist, ist auch ein Weg: Das auf Terpyridin basierende Titelsystem wurde in einem einfachen Selbstorganisationsprozess erhalten. Zwei Tris(terpyridin) ‐ Liganden mit Winkeln von 120 oder 60° zwischen benachbarten tpy ‐ Einheiten wurden mit einer stöchiometrischen Menge an Zn2+ (2:6:12) gemischt, was zur gewünschten koordinationsgetriebenen Fahrrad ‐ artigen Rad führte (90 % Ausbeute). [ABSTRACT FROM AUTHOR]