Self-assembly of Pyrene-modified Rhomboidal Metallodendrimers via Directional Metal-ligand Bonding Approach

The design and self-assembly of pyrene-modified rhomboidal metallodendrimers R1R6 via directional metal-ligand bonding approach is described. By employing pyrene-containing 120 degrees di-Pt(II) acceptor and appropriate 60 degrees 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.