Self-assembly of pyrene-modified rhomboidal metallodendrimers via directional metal-ligand bonding approach

The design and self-assembly of pyrene-modified rhomboidal metallodendrimers R1-R6 via directional metal-ligand bonding approach is described. By employing pyrene-containing 120° di-Pt(II) acceptor and appropriate 60° dendritic dipyridyl donors, a variety of [G-1]-[G-3] pyrene-modified rhomboidal metallodendrimers with well-defined shape and size were prepared under mild conditions in high yields. The supramolecular dendrimers were characterized with multinuclear NMR (¹H and ³¹P) and mass spectrometry (CSI-TOF-MS). Isotopically resolved mass spectrometry data support the existence of the pyrene-modified dendrimers with rhomboidal cavities, and NMR data were consistent with the formation of all ensembles. The shape and size of all rhomboidal dendrimers were investigated with the PM6 semiempirical molecular orbital method. Their primary photochemical properties were studied as well. A series of novel rhomboidal pyrene-modified metallodendrimers R1-R6 were constructed via directional metal-ligand bonding approach.