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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 113 (1991), S. 8367-8374 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 106 (1984), S. 3681-3682 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 98 (1976), S. 358-367 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Chemical reviews 93 (1993), S. 41-54 
    ISSN: 1520-6890
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European biophysics journal 3 (1977), S. 101-106 
    ISSN: 1432-1017
    Keywords: Retinal ; Polyenes ; Electronic structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract The implications that recent work on the electronic structure of polyenes have for the low lying electronic states of retinal are reviewed and a very simple model for the diffuseness of the absorption spectra of visual chromophores is presented.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 1684-1691 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Fluorescence and fluorescence excitation spectra for low temperature n-alkane solutions of α,ω-dithenylpolyenes with two, three, and four polyene double bonds have been measured. The fundamental frequencies in the vibronic development of the fully resolved spectra are either nearly identical to modes seen for unsubstituted polyenes or nearly identical to modes seen for polythiophene oligomers. The degree to which thiophene ring modes contribute to the spectra decreases with increasing polyene chain length. In the tetraene, the 2 1Ag state is 2760 cm−1 lower in energy than the 1 1Bu state, in the triene it is 1570 cm−1 lower, and in the diene these two states are nearly degenerate. The 2 1Ag and 1 1Bu excitation energies are well fit by a simple theoretical model which also gives a description of the π-electron distributions in the 1 1Ag, 2 1Ag, and 1 1Bu states.
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  • 7
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 3038-3042 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: It is now well established that the unsubstituted linear polyene 1,3,5,7-octatetraene efficiently undergoes cis–trans photoisomerization even when substituted in an n-alkane matrix cooled to liquid-helium temperatures. The fact that this photochemical reaction takes place under these conditions opens the possibility of using the techniques of photochemical hole burning to uncover details of the microscopic mechanism of this isomerization. In this paper we report the demonstration of photochemical hole burning for all-trans-octatetraene in n-hexane, show that the hole width for the zero-phonon component of the 0–0 band in the limit of zero temperature and zero hole depth is within experimental error equal to the value predicted from the measured fluorescence lifetime, analyze the dependence of hole width on temperature, and show that the relative quantum yield for hole burning increases by approximately a factor of 35 as vibrational energy in the excited state is increased beyond a threshold of approximately 950 cm−1. This threshold agrees well with the previously determined barrier to trans, cis isomerization.
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  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 908-917 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Vibrationally resolved optical spectra, fluorescence decay times, and fluorescence quantum yields have been measured for all-trans diphenyloctatetraene and all-trans diphenyloctatetraene substituted in the para position(s) of the phenyl ring(s) with an electron donor (MeO) or (and) and electron acceptor (CN). The electronic excitation energies, S0–S1 and S0–S2 transition dipoles and vibrational properties of the spectra provide a detailed picture of the effects of donor–acceptor substitution on the S0, S1, and S2 states. The electronic excitation energies are well fit by a simple parametrized quantum-mechanical model for polyene electronic structure which is used to estimate substituent-induced shifts in π-electron density in the S0, S1, and S2 states.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 5838-5842 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A simple model based on Huckel theory for interpreting linear polyene electronic structure is presented. The essential ingredients are the use of alternating resonance integrals to obtain the proper chain-length dependence of the 1 1Bu highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO) excitation energy and mixing of the HOMO to LUMO+1 and HOMO to LUMO double-excitation configurations to properly describe the 2 1Ag state. With the proper choice of parameters, this model reproduces all 25 2 1Ag and 1 1Bu 0–0 excitation energies that have thus far been measured for linear polyenes in low-temperature hydrocarbon solutions.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 6367-6376 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: In a previous letter [J. Chem. Phys. 92, 4622 (1990)] we reported the first observation of the 2 1Ag state of cis-hexatriene in a supersonic jet expansion by using resonance enhanced multiphoton ionization spectroscopy. Here, the vibrational analysis of the 1 1Ag→2 1Ag excitation spectrum of cis-hexatriene is presented. The excitation spectrum shows that cis-hexatriene in the 2 1Ag state deviates slightly from planarity; a conclusion which is corroborated by ab initio calculations indicating that the nonplanarity primarily involves the terminal hydrogen atoms. Except for observable intensity in the low frequency modes associated with the small out of plane distortion, the vibronic development of the 1 1Ag→2 1Ag transition in cis-hexatriene is similar to that observed for other polyenes: the 0–0 transition is the most intense feature and the next most intense band is the C(large-closed-square)C stretching fundamental. Thus the general features of the electronic structure of the cis-hexatriene 2 1Ag state are analogous to those of other polyenes.
    Type of Medium: Electronic Resource
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