Shortcut to Highly Fluorescent Perylene Derivatives: FromFluoranthene Fissure-Coupling to Late-Stage Aromatic Extension

Access to extended perylene-based nanographenes (NGs) is severely limited and involves tedious multi-step synthetic procedures. Here a two-step synthesis shortcut to highly soluble, bent, and extended perylene-based NGs from a nonperylene aromatic homologation precursor is reported. Moreover, the resulting scaffold, tetraphenyldibenzoperiflanthene (DBP), is further extended by Pd-based postsynthetic ring fusion, taking advantage of the installation of an aminoquinoline directing group. The rational extension of the DBP scaffold allows synthesizing of highly NIR fluorescent pure-red emitters (λem > 700 nm) with excellent quantum yields (ΦFI) up to 0.78. Thorough theoretical analysis sheds light on the correlation between λem, ΦFI, and scaffold molecular editing and extension, showcasing a rational design evolution process toward NGs with desired photophysical properties.