Table 1. Summary of the physical properties of the investigated compounds.

Emitter	λ abs a [nm]	λ em b [nm]	FWHMc [nm/eV]	E S1 d [eV]	E T1 e [eV]	ΔESTf [eV]	E g g [eV]	HOMOh [eV]	LUMOh [eV]	Ф PL i [%]
Spiro-3TCzBN	523	556	44/0.17	2.32	2.24	0.08	2.24	−4.87	−2.63	96
DPh-3TCzBN	529	568	54/0.18	2.33	2.24	0.09	2.21	−4.86	−2.65	92
DMe-3TCzBN	526	565	49/0.19	2.32	2.24	0.08	2.22	−4.87	−2.65	95

^aPeak wavelength of the lowest energy absorption band.

^bPeak wavelength of the PL spectrum in toluene (1 × 10⁻⁵ M, 298 K).

^cFull width at half maximum of the spectra given in wavelength and energy.

^dSinglet energy estimated from the onset of the fluorescence spectrum in toluene (10⁻⁵ M, 77 K).

^eTriplet energy estimated from the onset of the phosphorescence spectrum in a frozen toluene matrix (10⁻⁵ M, 77 K).

^fΔE_ST = E_S1 – E_T1.

^gOptical band gap estimated from the absorption edge of the UV-vis spectrum.

^hDetermined from cyclic voltammetry using the formula: E_HOMO = – (E_ox + 4.8) eV, E_LUMO = – (E_re + 4.8) eV.

ⁱAbsolute photoluminescence quantum yield measured with an integral-sphere system in N₂-bubbling toluene.