Coordination-Driven Self-Assembly of Metallodendrimers Possessing Well-Defined and Controllable Cavities as Cores

The design and self-assembly of novel cavity-cored metallodendrimers via noncovalent
interactions are described. By employing [G0]−[G3] 120° ditopic donor linkers substituted with Fréchet-type dendrons and appropriate rigid di-Pt(II) acceptor subunits, [G0]−[G3]-rhomboidal metallodendrimers
and [G0]−[G3]-hexagonal, “snowflake-shaped” metallodendrimers with well-defined shape and size were
prepared under mild conditions in high yields. The assemblies were characterized with multinuclear NMR
(1H and 31P), mass spectrometry (ESI-MS and ESI-FT-ICR-MS), and elemental analysis. Isotopically resolved
mass spectrometry data support the existence of the metallodendrimers with rhomboidal and hexagonal
cavities, and NMR data are consistent with the formation of all ensembles. The structures of [G0]- and
[G1]-rhomboidal metallodendrimers were unambiguously confirmed via single-crystal X-ray crystallography.
The shape and size of two [G3]-hexagonal metallodendrimers were investigated with MM2 force-field
modeling.