Anionic Bipyridyl Ligands for Applications in Metallasupramolecular Chemistry

Abstract

The facile synthesis of anionic bipyridyl ligands with dinuclear clathrochelate cores is described. These metalloligands can be obtained in high yields by the reactions of M(ClO 4 ) 2 (H 2 O) 6 (M: Zn, Mn, or Co) with 4-pyridylboronic acid and 2,6-diformyl-4-methylphenol oxime or 2,6-diformyl-4-tert-butylphenol oxime, followed by deprotonation.The ligands are interesting building blocks for metallasupramolecular chemistry, as evidenced by the formation of a Ptbased molecular square and four coordination polymers with 2D or 3D network structures. Competition experiments reveal that the utilization of anionic bipyridyl ligands can result in significantly more stable assemblies.

PdII2L4-type coordination cages up to three nanometers in size

“…12,13 The synthesis of these ligands can be achieved by a metal-templated condensation reaction of a dioxime and an arylboronic acid, 12,14 where different functional groups can be introduced by using an appropriate boronic acid or by performing post-synthetic cross-coupling reactions. 15 Iron( ii ) is particularly suited as metal template because the resulting complexes are robust and diamagnetic.…”

Self‐Assembly of a Giant Molecular Solomon Link from 30 Subcomponents

“…Standard small molecule approaches are insufficient to tackle supramolecular structures with these characteristics, and only a series of carefully adapted macromolecular refinement techniques enabled us to overcome this challenge and complete the structural model. As in other cases of huge and complicated supramolecular structures with high solvent content,24, 25 the application of geometric restraint dictionaries generated with the Grade Web Server26 and rigid bond restraints27 were key for successfully building a complete molecular model. Local structural similarity restraints (LSSR) exploiting noncrystallographic symmetry (NCS)28 were additionally applied here.…”

DSR: enhanced modelling and refinement of disordered structures with SHELXL

“…The structure consists of supramolecular clathrochelate ligands with a zinc ion in the centre, connected via cadmium ions to form a network (Pascu et al, 2014). In this case, 64% of the main-residue disorder is triggered by the disorder of the Cd ions over a special position (inversion centre) to which the clathrochelate ligands are coordinated.…”

“…The database contains over 70 entries of commonly disordered solvent molecules and molecular fragments, such as tetrahydrofuran, toluene, dichloromethane, tert-butyl groups, hexane and the tosylate anion, and also less common molecules like supramolecular ligands (Pascu et al, 2014;Ronson et al, 2013;Ramadhar et al, 2015) and molecules that have been soaked into porous metal-organic framework complexes (Inokuma et al, 2013). The complete list at the time of writing is available in the supporting information (the pictures therein were drawn using Jmol; http://www.jmol.org/).…”