Exceptional Oxygen Sensing Capabilities and Triplet State Properties of Ir(ppy-NPh₂)₃

Abstract

Strong oxygen quenching following a Stern−Volmer behavior of Ir(ppy-NPh2)3 demonstrates the high technological potential for oxygen sensing applications. This compound exhibits a phosphorescence quantum yield of 70% and an emission decay time of 4.3 μs in deaerated solution. The electronic structure of the emitting triplet, being responsible for these properties, is investigated.

Visible‐Light Harvesting with Cyclometalated Iridium(III) Complexes Having Long‐Lived 3IL Excited States and Their Application in Triplet–Triplet‐Annihilation Based Upconversion

“…The accessible 3 IL excited states of Ir-2 and Ir-4 upon excitation were unambiguously proved by nanosecond timeresolved transient difference absorption spectroscopy (Figure 4). For Ir-2, weak bleaching at 400 nm (MLCT band) was observed upon excitation.…”

“…[28] Superimposable excitation and UV/Vis absorption spectra for the dyads are shown in the Supporting Information, indicating that the intense absorption at 466 nm is efficient enough to produce the emissive triplet excited state. [29] Assignment of the 3 …”

“…The visible-light harvesting and the long-lived 3 IL excited state of dyads Ir-3 and Ir-4 inspired us to employ these novel complexes as triplet sensitizers to initiate a photophysical process. Herein we selected upconversion based on triplet-triplet-annihilation (TTA), [21][22][23][24] which requires triplet sensitizers to harvest excitation light and transfer the energy to a triplet acceptor (see Jablonski diagram, Scheme 2, for photophysical details).…”

Exceptional Oxygen Sensing Properties of New Blue Light‐Excitable Highly Luminescent Europium(III) and Gadolinium(III) Complexes

“…[3]or by complicated multistep synthesis. Such indicators as cyclometalated iridium(III) and platinum(II) complexes, [15][16][17] osmium(II), [18] rhenium(I) [19] and copper(I) [20,21] complexes should also be mentioned. Europium(III) complexes represent a particularly interesting group of luminescent compounds which are distinguished by their very large Stokes shifts, long luminescence decay times (hundreds of µs -few ms) and very narrow emission bands.…”

Indicators for optical oxygen sensors

“…The modified complexes were shown to possess relatively high cellular uptake but, compared to 68, their quantum yields were only moderate (< 0.2). A substitution of the ppy ligands in complex 68 with ppyNPh 2 leads to the formation of a new cyclometalated indicator: [Ir(ppy-NPh 2 ) 3 ] 69 which has the advantage of being less sensitive to self-quenching and is even better soluble in organic solvents and organic polymers [149]. Complex 69 has a high phosphorescence quantum yield (~70 %), lifetime in the order of several microseconds (Table 4), can be excited at 405 nm and therefore is compatible with low-cost LED as excitation source and its excitation and emission spectra are well shifted.…”