Manipulating Excited State Properties of Iridium Phenylpyridine Complexes with “Push–Pull” Substituents

Abstract

We have prepared a series of complexes of the type [Ir III (ppy) 2 (L] n+ complexes (1−4), where ppy is a substituted 2phenylpyridine and L is a chelating phosphine thioether ligand. The parent complex (1) comprises an unsubstituted phenylpyridine ligand, whereas complex 2 contains a nitro substituent on the pyridine ring, complex 3 features a diphenylamine group on the phenyl ring, and 4 has both nitro and diphenylamine groups. Crystallographic, 1 H NMR, and elemental analysis data are consistent with each of the chemical formulae. DFT (density functional theory) computational results show a complicated electronic structure with contributions from Ir, ppy, and the PS ligand. Ultrafast pump−probe data show strong contributions from the phenylpyridine moieties as well as strong panchromatic excited state absorption transitions. The data show that nitro and/or diphenylamine substituents dominate the spectroscopy of this series of compounds.

Synergizing supramolecular chemistry and reverse saturable absorption: exploring pillar[5]arene with metal-complexed ligands

“…Metal-complexed materials, particularly those with cyclometalating ligands, exhibit strong RSA properties due to their unique electronic structures. 9,10 These materials are being explored for advanced photonics applications, 11 including ultrafast nonlinear absorption and optical switching. 12 Their ability to transition between saturable and reverse saturable absorption opens new avenues in all-optical logic and photonic devices, underscoring their importance in modern optical technologies offering a pathway to enhanced optical limiting and photoprotection.…”