Palladium Catalyzed, Annulative Multiple C-H Bond Activations of BODIPYs to Access π-Extended Polycyclic Heteroaromatic Molecules with Deep Red Emissions and Self-aggregation Behaviors.

Aromatic ring fusion on BODIPY core can effectively tune its electronic property, and red-shift its absorption and emission wavelength. In this work, we report that a one-pot Pd(II) catalyzed multiple C-H activation to access acenaphtho[b]-fused BODIPYs though the reaction of α,ß-unsubstituted-BODIPYs and 1,8-dibromonaphthalenes. These newly synthesized acenaphtho[b]-fused BODIPYs revealed intensified deep red absorptions (639-669 nm) and emissions (643-683 nm), with high fluorescence quantum yields (0.53-0.84) in dichloromethane. Notably, these acenaphtho[b]-fused BODIPYs exhibited well-defined self-aggregation behavior in water/THF mixture, and for instance, the absorption of 3 a was red-shifted by 53 nm to 693 nm after forming aggregates.

Direct Synthesis of Dipyrrolyldipyrrins from SNAr Reaction on 1,9-Dihalodipyrrins with Pyrroles and Their NIR Fluorescence "Turn-On" Response to Zn2.

A set of dipyrrolyldipyrrins have been efficiently synthesized from a direct SNAr reaction on 1,9-dihalodipyrrins with pyrroles and show intense absorption in the NIR region (650-800 nm, as HCl salts). Substituents on both 1,9-dihalodipyrrins and pyrroles greatly affected the reactivity of this SNAr reaction and the absorption properties of the resultant dipyrrolyldipyrrins. These dipyrrolyldipyrrins show sensitive and selective "turn-on" fluorescence response toward Zn2+.