Cooperativity of steric bulk and H-bonding in coordination sphere engineering: heteroleptic PdII cages and bowls by design. Issue 6 (26th January 2022)

• Record Type: Journal Article
• Authors: Chen, Bin; Holstein, Julian J.; Platzek, André; Schneider, Laura; Wu, Kai; Clever, Guido H.
• Is Part Of: Chemical science. Volume 13:Issue 6(2022)
• Page Start: 1829
• Page End: 1834
• Publication Date: 2022-01-26
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d1sc06931d
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Coordination Sphere Engineering (CSE) allows non-statistical assembly of heteroleptic supramolecular architectures by fine adjustment of steric and electronic features around square-planar Pd(ii ) cations with naphthyridine donors. Abstract : Recently developed self-assembly strategies allow to rationally reduce the symmetry of metallosupramolecular architectures. In addition, the combination of multiple ligand types without creating compound mixtures has become possible. Among several approaches to realize non-statistical heteroleptic assembly, Coordination Sphere Engineering (CSE) makes use of secondary repulsive or attractive interactions in direct vicinity of the metal nodes. Previously, we used steric congestion to turn dinuclear [Pd2 L4 ] cages with fourfold symmetry into [Pd2 L3 X2 ] (X = solvent, halide) bowl structures. Here, we introduce a new subtype of this strategy based on balancing hydrogen bonding and repulsive interactions between ligands carrying quinoline (L Qu ) and 1, 8-naphthyridine (L Na ) donors to generate trans -[Pd2 L2 ] and [Pd2 L3 L′] cages, assisted by templation of encapsulated fullerenes. Combined with steric congestion caused by acridine (L Ac ) donors, we further report the first example of a heteroleptic [Pd2 L2 L′X2 ] bowl. Formation, structure and fullerene binding ability of these metallo-supramolecular hosts were studied by NMR, mass spectrometry and single crystal X-ray diffraction.