A porphyrin(2.1.2.1) bis-boron complex as a deep-red AIE luminophore induced by intermolecular F-π interaction.

Mono-/diboron complexes with saddle-shaped molecular conformations were synthesized from porphyrins(2.1.2.1). The boron complexes have unique structure-dependent photophysical properties: (a) monoboron complexes 2a and 2b are not emissive in solution and the solid state, (b) diboron complex 3a shows red emission in toluene, and (c) diboron complex 3b shows aggregation-induced emission (AIE) in the deep-red region due to intermolecular secondary interactions (F-π). This is the first case of a boron porphyrinoid complex that shows AIE emission in the deep-red region in decades.

Synthesis of Planar meso-Aryl Rosarins: A Reversible Antiaromatic/Aromatic Interconversion.

Novel 24π antiaromatic and 26π aromatic meso-aryl rosarins were successfully obtained for the first time from ß-free bipyrrole through a one-pot synthesis. Because of the absence of substituents at the ß-positions of the pyrrole units, the ß-free pristine rosarin backbones were highly planar, as confirmed using X-ray crystallography. Optical measurements indicated interconversion between 24π antiaromatic and 26π aromatic ß-free pristine rosarin via redox reactions, which was not observed in distorted ß-dodecamethyl rosarin.