Photoactive metal complexes employing Earth‐abundant metal ions are a key to sustainable photophysical and photochemical applications. We exploit the effects of an inversion center and ligand non‐innocence to tune the luminescence and photochemistry of the excited state of the [CrN6] chromophore [Cr(tpe)2]3+ with close to octahedral symmetry (tpe=1,1,1‐tris(pyrid‐2‐yl)ethane). [Cr(tpe)2]3+ exhibits the longest luminescence lifetime (τ=4500 μs) reported up to date for a molecular polypyridyl chromium(III) complex together with a very high luminescence quantum yield of Φ=8.2 % at room temperature in fluid solution. Furthermore, the tpe ligands in [Cr(tpe)2]3+ are redox non‐innocent, leading to reversible reductive chemistry. The excited state redox potential and lifetime of [Cr(tpe)2]3+ surpass those of the classical photosensitizer [Ru(bpy)3]2+ (bpy=2,2′‐bipyridine) enabling energy transfer (to oxygen) and photoredox processes (with azulene and tri(n‐butyl)amine).

Photoactive metal complexes employing Earthabundant metal ions are ak ey to sustainable photophysical and photochemical applications.W ee xploit the effects of an inversion center and ligand non-innocence to tune the luminescence and photochemistry of the excited state of the [CrN 6 ] chromophore [Cr(tpe) 2 ] 3+ with close to octahedral symmetry (tpe = 1,1,1-tris(pyrid-2-yl)ethane). [Cr(tpe) 2 ] 3+ exhibits the longest luminescence lifetime (t = 4500 ms) reported up to date for am olecular polypyridyl chromium(III) complex together with av ery high luminescence quantum yield of F = 8.2 %a t room temperature in fluid solution. Furthermore,t he tpe ligands in [Cr(tpe) 2 ] 3+ are redox non-innocent, leading to reversible reductive chemistry.The excited state redoxpotential and lifetime of [Cr(tpe) 2 ] 3+ surpass those of the classical photosensitizer [Ru(bpy) 3 ] 2+ (bpy = 2,2'-bipyridine) enabling energy transfer (to oxygen) and photoredox processes (with azulene and tri(n-butyl)amine).Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.org/10.

Inversion symmetry increases the excited‐state lifetime of a molecular ruby at room temperature in fluid solution to 4.5 ms while the photoluminescence quantum yield remains as high as 8.2 %, as shown by K. Heinze and co‐workers in their Research Article on page 18075. The chromium(III) complex [Cr(tpe)2]3+ is furthermore competent in light‐induced electron and energy transfer processes, and thus resembles classical noble metal complexes.

Durch Inversionssymmetrie erhöht sich die Lebensdauer des angeregten Zustands eines molekularen Rubins bei Raumtemperatur in flüssiger Lösung auf 4.5 ms, während die Photolumineszenzquantenausbeute bis zu 8.2 % beträgt. In ihrem Forschungsartikel auf S. 18243 zeigen K. Heinze et al., dass der Chrom(III)‐Komplex [Cr(tpe)2]3+ sich zudem für lichtinduzierte Energie‐ und Elektronenübertragungsprozesse eignet und insofern klassischen Edelmetallkomplexen ähnelt.