Table 1.

Photophysical data of the isomers in 1 × 10⁻⁵ M THF solutions.

Compound	λabs (nm)	λemi (nm)	Stokes Shift (nm)	τf (ns)	Φf,s a	kf b (s−1)	knr b (s−1)
o-DBCNPy	408	549	141	1.10	0.11	1.00 × 108	8.09 × 108
m-DBCNPy	402	541	139	0.85	0.10	1.18 × 108	1.06 × 109
p-DBCNPy	413	566	153	0.81	0.08	9.88 × 107	1.14 × 109

^a Fluorescence quantum yield in THF solutions. Rhodamine B (0.7 in ethanol) was used as the reference [18]. ^b k_f, radiative decay rate constant (k_f = Φ_f,s/τ_f); k_nr, nonradiative decay rate constant (k_nr = 1/τ_f − k_f) [43].