Moderately high resolution fluorecence spectrum of the S1 → S0 transition of azulene

Friedman, Joel M.; Hochstrasser, Robin M.

doi:10.1016/0301-0104(74)85056-1

Cited by 32 publications

(2 citation statements)

References 13 publications

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“…Azulene, the nonalternant aromatic isomer of naphthalene, is known to have unusual photophysical properties. − In contrast with the vast majority of aromatic molecules which show S 1 → S 0 fluorescence under low excitation intensity, azulene fluoresces from the second excited state to S 0 with quantum yield η S 2 → S 0 = 0.046 in cyclohexane solution at room temperature and to S 1 (η S 2 → S 1 ≈ 4 × 10 -6 ) in methylcyclohexane glass at 77 K , while only very weakly from S 1 to S 0 (η S 1 → S 0 < 10 -6 ) with laser excitation . The depopulation process from S 1 in condensed media has been extensively investigated with subpicosecond pump−probe experiments. − In the most recent study, the S 1 decay time of azulene in cyclohexane solution was accurately determined as a function of the excess vibrational energy above the S 1 origin, decreasing from 1.7 ps at the origin to ≈0.4 ps 1300 cm -1 higher.…”

Section: Introductionmentioning

confidence: 99%

S₁ → S_n and S₂ → S_n Absorption of Azulene: Femtosecond Transient Spectra and Excited State Calculations

et al. 2003

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The transient spectra of azulene in solution have been measured in the spectral region 600−350 nm at room temperature, pumping into the S1 and S2 states with femtosecond pulses and probing with a delayed femtosecond white light continumm. The spectra are a combination of ground-state bleaching, stimulated emission, and excited-state absorption. The latter component gives a direct information on excited states which may be not active in the ground-state absorption. S1 → S n and S2 → S n absorptions have been discussed with the help of ab initio calculations of the MCSCF/CAS type with the 6-31G* basis set and including perturbative corrections. The calculated S0 → S n , S1, eq → S n , and S2, eq → S n vertical excitation energies and oscillator strengths are in satisfactory agreement with the experimental results. It has been found that electronic states, weakly active in the ground-state absorption, occur with high intensity in the femtosecond transient spectra, in particular in the energy range 36000−44000 cm-1 above the ground-state energy.

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Section: Introductionmentioning

confidence: 99%

S₁ → S_n and S₂ → S_n Absorption of Azulene: Femtosecond Transient Spectra and Excited State Calculations

et al. 2003

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“…For such molecules, the first excited singlet state S 1 is very short lived (∼1 ps) due to a conical intersection [7] and, as a consequence, a strong nonradiative decay of the transition S 1 → S 0 . However, a higher excited singlet state S 2 is long lived (∼1 ns) displaying a strong fluorescence band that corresponds to transition S 2 → S 0 [8][9][10][11]. Because of this, there are also reasons to consider a coherent population transfer to higher excited singlet states (S 2 ) of the molecules under discussion.…”

Section: Introductionmentioning

confidence: 99%

Stimulated Raman Adiabatic Passage in a Dense Medium

Fainberg

Levinsky

2010

Advances in Physical Chemistry

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We have considered a coherent population transfer to a higher excited singlet state (S2) of molecules with anomalous fluorescence in molecular assemblies (e.g., a dense medium). A direct excitation to S2 requires light in the UV region. Because of this, the transition is conveniently realized by a two-step (two-photon) process: S0→S1→S2, where transitions S0→S1 and S1→S2 correspond to the optical region. We have shown that efficient stimulated Raman adiabatic passage (STIRAP) in the ladder configuration can be realized in this case, using suitably chirped pulses, to compensate a change of the two-photon transition frequency in time, induced by the pulses themselves, due to near dipole-dipole interactions. We have provided a reduced state formulation of the optical control process. Chirping the “pump” pulse that excites transition S0→S1 is nonequivalent to chirping the “Stokes” pulse that excites transition S1→S2, with respect to the population of the intermediate state (S1) in the pulse nonadiabatic regime. We have also shown that with suitably chirped pulses, efficient STIRAP still persists even for a rather large decay of the intermediate state.

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Statistical Aspects of Resonance Light Scattering in the Condensed Phase

Hochstrasser

Novak

Nyi

1977

Israel Journal of Chemistry

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A practical approach to understanding light scattering processes in the condensed phase is presented. First a theoretical discussion of the various parameters in resonance light scattering is given and there is a special emphasis on our simplified approach to this question. As with other approaches the two level density matrix in association with a quantum regression theorem leads to two types of emission from an ensemble of molecules at finite temperature (T2 ≠ 2T1). We have called one of these fluorescence and the other sharper emission Raman scattering because it results directly from the presence of a coherent polarization in the medium. A brief discussion of time dependent scattering is also given. An experiment that reproduces the main features of the theory is described for resonance scattering from azulene in naphthalene at 30 K. For all values of the laser frequency (near resonance) both a sharp (Raman) and diffuse (fluorescent) component occurs in the emission spectrum. These spectra when interpreted by the simplified theory yield a value of T2 = 0.7 ps from fluorescence linewidth, and T2 = 0.8 ps from the incoherent to coherent scattering ratio, for the 0–0 two level system of azulene in naphthalene. A discussion of practical aspects of the influence of inhomogeneous line broadening is also presented.

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Moderately high resolution fluorecence spectrum of the S1 → S0 transition of azulene

Cited by 32 publications

References 13 publications

S₁ → S_n and S₂ → S_n Absorption of Azulene: Femtosecond Transient Spectra and Excited State Calculations

S₁ → S_n and S₂ → S_n Absorption of Azulene: Femtosecond Transient Spectra and Excited State Calculations

Stimulated Raman Adiabatic Passage in a Dense Medium

Statistical Aspects of Resonance Light Scattering in the Condensed Phase

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Moderately high resolution fluorecence spectrum of the S1 → S0 transition of azulene

Cited by 32 publications

References 13 publications

S1 → Sn and S2 → Sn Absorption of Azulene: Femtosecond Transient Spectra and Excited State Calculations

S1 → Sn and S2 → Sn Absorption of Azulene: Femtosecond Transient Spectra and Excited State Calculations

Stimulated Raman Adiabatic Passage in a Dense Medium

Statistical Aspects of Resonance Light Scattering in the Condensed Phase

Contact Info

Product

Resources

About

S₁ → S_n and S₂ → S_n Absorption of Azulene: Femtosecond Transient Spectra and Excited State Calculations

S₁ → S_n and S₂ → S_n Absorption of Azulene: Femtosecond Transient Spectra and Excited State Calculations