Near-Infrared Phosphorescent Iridium(III) Benzonorrole Complexes Possessing Pyridine-based Axial Ligands.

Novel near-infrared phosphorescent iridium(III) complexes based on benzo-annulated N-linked corrole analogue (termed as benzonorrole) were synthesized. The structures of the complexes revealed octahedral coordination geometries involving an organometallic iridium-carbon bond with two external axial ligands. Interestingly, the iridium(III) complex exhibits near-infrared phosphorescence at room temperature at wavelengths beyond 900 nm. The significant redshift of the emission, as compared to the corrole congener, is originated from the ligand-centered triplet character. The fine-tuning of the photophysical properties of the complexes was achieved by introducing electron-donating and electron-withdrawing substituents on the axial pyridine ligands.

Synthesis and reactivity of 5,10,15-triaryl doubly N-confused bilanes.

A series of 5,10,15-tris(pentafluorophenyl) doubly N-confused bilanes were synthesized in a stepwise manner with the aid of sterically demanding N-protecting groups, in which the difference in reactivity between regular pyrrole and N-confused pyrrole plays a crucial role in the synthetic strategy. Some doubly N-confused bilanes were converted into porphyrinoids or a unique 2:2 copper(II) complex with a helical structure. In addition, the conformations and electronic states of the doubly N-confused bilanes were investigated theoretically, giving fruitful information about the effect of confusion on the bilane skeleton.

C-fused norrole: a fused corrole isomer bearing a N,C-linked bipyrrole unit.

Oxidative cyclization of a doubly N-confused bilane afforded a N-confused N,C-linked corrole (N-confused norrole), which was readily oxidized to form a C-fused N,C-linked corrole (C-fused norrole).