NIR-emissive iridium(iii) corrole complexes as efficient singlet oxygen sensitizers

Abstract

Three new iridium(iii) corrole complexes, having symmetrically and asymmetrically substituted corrole frameworks and judiciously varied axial ligands are prepared and characterized by various spectroscopic techniques including the X-ray structures of two of them. The observed phosphorescence at ambient temperature appears at much longer wavelengths than the previously reported Ir(iii) porphyrin/corrole derivatives. Efficiencies of these compounds in the generation of singlet oxygen are also studied for the first time.

Development of iridium porphyrin arrays by axial coordination through N-bidentate ligand: Synthesis and evaluation of the optical, electrochemical and thermal properties

“…The high correlation amongst the calculated and measured m/z values of each fragments peaks allows to confirm the axial coordination of two bipyridine molecules to the iridium metal center on the porphyrin cavity. These results are in agreement with the structure identified by 1 H NMR, where the upfield shifting proton resonances of ligand may be due to the shielding effect caused by the porphyrin ring current and indicate of metalloporphyrin selfassembly [16,22,33].…”

“…Iridium complexes have attracted more attention than other common metals and d-block metals due to their larger spin-orbit constant, heavier atomic mass and their emission energies that can be easily adjusted across the visible spectrum [21]. Iridium porphyrins in particular, has been the target of great notoriety on the part of researchers due to their interesting properties in a wide range of applications, including catalysis, sensors and switching layers in electronic devices [21][22][23].…”

Osmium-nitrido corroles as NIR indicators for oxygen sensors and triplet sensitizers for organic upconversion and singlet oxygen generation

“…We may conclude that osmium-nitrido corroles show comparable or higher efficiency of 1 O 2 sensitization than the metal-free corroles and the respective Ga(III) complexes (F D 0.34-0.86; 64 0.51-0.77 65 ) and are much more powerful 1 O 2 generators than Ir(III) corroles (F D 0.09-0.15). 43…”

“…40 Many of them exhibit bright fluorescence; 41,42 only a few, however, have been shown to possess NIR phosphorescence at room temperature. The latter class of complexes includes iridium corroles, 43,44 a gold(III) b-octabromocorrole, 45 and aluminium and gallium complexes of b-iodinated corroles. 46 A variety of other 5d metallocorroles, including rhenium, 47 osmium, 48 gold, [49][50][51] and platinum 52 corroles, which might be expected to exhibit NIR phosphorescence, have been synthesized in recent years.…”

Photophysical Heavy-Atom Effect in Iodinated Metallocorroles: Spin–Orbit Coupling and Density of States

“…Importantly, corroles and their metal complexes are excellent agents for photodynamic therapy and inhibition, cancer-targeted imaging and tumor elimination, 25,26,27,28,29 as well as solarcell 30,31 and singlet-oxygen 22,24,32,33,34,35 photosensitizers. It is also possible to envisage corroles as active components of electron-and energy transfer supramolecular assemblies, although this opportunity has been explored less.…”