Absorption (top) and photoluminescence (bottom) spectra of [Ir(ppy)3] (green), [Ir(ppy)2(dtb)]+ (dark green), [Ir((dFCF3)ppy)2(dtb)]+ (blue), [Ru(bpy)3]2+ (orange), [Os(bpy)3]2+ (red), [Fe(phtmeimb)2]+ (pink), [Fe(Br-phtmeimb)2]+ (violet), [Cu(bcp)2]+ (black, recorded in dichloromethane), and [Cu(bcp)(DPEPhos)]+ (light blue) recorded at room temperature in argon purged acetonitrile.