Sn ← S1 and Tn ← T1 absorption spectra of highly purified chrysene in solution

Quenching processes of aromatic hydrocarbons in the higher triplet excited states-energy transfer vs. electron transferElectronic supplementary information (ESI) available: The quenching of DBA(Tn) by CCl4, CHR(Tn) by NAP, the evidences of no DBA and CHR ions produced during two-color two-laser flash photolysis, and the evidence of formation of benzene/Cl complex. See http://www.rsc.org/suppdata/cp/b4/b400128a/

“…The DE T 2 -T1 values between the T 1 and T 2 states for NAP and CHR are theoretically calculated to be 1.17 and 1.75 eV, while DE T 3 -T1 values of NAP and CHR are 1.29 and 2.03 eV, respectively. [32][33][34] Therefore, NAP(T n ) and CHR(T n ) are assigned to NAP(T 2 ) and CHR(T 2 ), respectively. Since no theoretical study has been reported on DBA(T n ), the triplet manifolds of DBA(T n ) can not be determined.…”

Rate Constant of Bimolecular Triplet Energy Transfer from Chrysene in the Higher Triplet Excited States

“…With α = 3.3 eV -1 and τ = 45 ± 7 ps ( k IC = (2.3 ± 0.3) × 10 10 s -1 ), the Δ E value between the T 1 and T n states (Δ E Tn - T1 ) of chrysene was calculated to be 1.85 ± 0.05 eV. The Δ E T2 - T1 value between the T 1 ( E T1 = 2.48 eV) and T 2 ( E T2 = 4.23 eV) states for chrysene is theoretically calculated to be 1.75 eV, while Δ E T3 - T1 of chrysene is 2.03 eV. , Therefore, theobserved IC corresponds to that from chrysene(T 2 ). Because the energy of the 532-nm photon is 2.33 eV, which is much higher than the Δ E T2 - T1 , the chrysene(T n , n > 2) states should be initially generated and deactivated through the fast IC to chrysene(T 2 ) with the longest τ (45 ± 7 ps) among chrysene(T n ) (eq 7), …”

“…Direct Measurement of Lifetime of Chrysene(T 2 ). When chrysene (1.0 × 10 -3 M) was irradiated at 355 nm using a ns Nd:YAG laser in Ar-saturated cyclohexane, a transient absorption spectrum of chrysene in the lowest triplet excited state (chrysene(T 1 )) with a peak around 570 nm (extinction coefficient, ε 570 = 29800 M -1 cm -1 ) was observed (Figure a). , The quantum yield ( Φ T ) of intersystem crossing (ISC) from chrysene(S 1 ) to chrysene(T 1 ) is 0.85 and the τ value of chrysene(T 1 ) is longer than 3.4 μs (eq 4). , Because chrysene(T 1 ) has an absorption at 532 nm, chrysene(T 1 ) is selectively excited to chrysene in the higher triplet excited state (chrysene(T n )) with the second 532-nm ps laser irradiation to the sample at 100 ns after the first 355-nm ns laser irradiation. Bleaching of the transient absorption of chrysene(T 1 ) was observed within a 532-nm laser flash duration; then, the transient absorption was completely recovered in the 100−200 ps time range as shown in Figures and , which was not observed during the ns−ns two-color two-laser flash photolysis .…”

“…The triplet energy transfer quenching of chrysene(T 2 ) by Q such as biphenyl, naphthalene, or carbon tetrachloride (CCl 4 ) has been observed previously. 10 Since E T1 of biphenyl or naphthalene is higher than chrysene(T 1 ) (2.48 eV) 8,12 and lower than chrysene-(T 2 ) (4.23 eV), Q can act as a triplet energy acceptor for chrysene(T 2 ) with large exothermic energy, but not for chrysene-(T 1 ) (eq 8),…”

Development of real-time vibrational spectroscopy of molecules in electronic excited states: toward mapping molecular potential energy hypersurfaces

“…Chrysene is one of most extensively studied molecules by absorption, emission, and Raman spectroscopies [51][52][53]. Thus, its properties are well known; it has an S 1 lifetime of 40 ns and an intersystem crossing quantum efficiency of greater than 0.81 [52]. As shown in Fig.…”