Construction of supramolecular pyrene-modified metallacycles via coordination-driven self-assembly and their spectroscopic behavior

The design and self-assembly of novel multipyrene hexagonal metallacycles via coordination-driven self-assembly is described. By employing newly designed 120 dipyridine donor and di-Pt(II) acceptor linkers substituted with pyrene, a variety of tris- and hexakis(pyrene) hexagonal metallacycles with well-defined shape and size were prepared via [3 + 3] and [6 + 6] self-assembly, respectively, under mild conditions in high yields. The structures of these novel metallacycles were well characterized by multinuclear NMR (³¹P and ¹H) spectroscopy, cold-spray ionization time-of-flight mass spectrometry (CSI-TOF-MS), electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), and elemental analysis. The shape and size of all hexagonal metallacycles were investigated by the PM6 semiempirical molecular orbital method. The preliminary study of their spectroscopic behavior was also carried out. It was found that these pyrene-modified metallacycles displayed different optical behaviors, which might be caused by the structural effects.