“…Some properties of the triplet state of mono- and dinitronaphthalenes have been reported. , The triplet energy ranges from E T = 190 kJ mol -1 for DNF to 210 kJ mol -1 for 1,4-DNN and further to 240 kJ mol -1 for DNB. , The quantum yield of triplet formation of the dinitroarenes is substantial in solution at room temperature, Φ isc = 0.6−0.8 for 1,3- and 1,4-DNN, and in glassy media at −196 °C. , The quantum yield of singlet oxygen formation (Φ Δ ) as lower limit of Φ isc and further triplet state characteristics are compiled in Table . Φ isc = 0.7 for DNB in methanol has been concluded from results of photoreduction in the presence of MeO - 1 T-T Absorption Maxima, Lifetime, and Relative Triplet Yield, a Rate Constant for Quenching by Oxygen and Quantum Yield of Singlet Oxygen compound | λ TT b (nm) | τ T c (μs) | k ox (× 10 9 M -1 s -1 ) | Δ A T /Δ A T max | Φ Δ d |
1,3-DNN | 430 ,550 | 7 | 1.1 | 0.8 | 0.6 (0.65) |
1,4-DNN | 410, 550 | 10 | 1.2 | 0.9 | 0.6 (0.68) |
1,5-DNN | 410, 540 | 10 | 1.2 | 0.6 | 0.4 (0.47) |
1,8-DNN | 400,540 | 8 | 1.2 | | |
2,3-DNN | 470 | 0.08 | <2 | 0.8 | |
DNB | 510 | 0.14 | <2 | 0.8 | |
DNF | 510 | 10 | 0.8 | 1.0 | 0.6 (0.65) |
a In argon-saturated acetonitrile.…”