Dokumentenart: | Artikel | ||||
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Titel eines Journals oder einer Zeitschrift: | Journal of Physical Chemistry A | ||||
Band: | 109 | ||||
Nummer des Zeitschriftenheftes oder des Kapitels: | 4 | ||||
Seitenbereich: | S. 576-585 | ||||
Datum: | 2005 | ||||
Zusätzliche Informationen (Öffentlich): | CAN 142:218880 22-9 Physical Organic Chemistry 635-90-5 (N-Phenylpyrrole); 23351-07-7 Role: PEP (Physical, engineering or chemical process), PRP (Properties), PYP (Physical process), PROC (Process) (charge-transfer-type fluorescence of pyrrolylbenzonitrile and phenylpyrrole in cryogenic matrixes) | ||||
Institutionen: | Chemie und Pharmazie > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry III - Physical Chemistry (Molecular Spectroscopy and Photochemistry) > Prof. Dr. Bernhard Dick | ||||
Identifikationsnummer: |
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Stichwörter / Keywords: | Density functional theory (B3LYP, charge-transfer-type fluorescence of pyrrolylbenzonitrile and phenylpyrrole in cryogenic matrixes); CASSCF; Charge transfer state; Cluster model; Dipole moment; Electron density; Lennard-Jones potential; Localized electronic state; Solvatochromism; Vibronic transition (charge-transfer-type fluorescence of pyrrolylbenzonitrile and phenylpyrrole in cryogenic matrixes); Fluorescence (dual, charge-transfer-type fluorescence of pyrrolylbenzonitrile and phenylpyrrole in cryogenic matrixes); Molecular structure (optimized, charge-transfer-type fluorescence of pyrrolylbenzonitrile and phenylpyrrole in cryogenic matrixes); fluorescence CT pyrrolylbenzonitrile phenylpyrrole cryogenic matrix | ||||
Dewey-Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik > 540 Chemie | ||||
Status: | Veröffentlicht | ||||
Begutachtet: | Ja, diese Version wurde begutachtet | ||||
An der Universität Regensburg entstanden: | Zum Teil | ||||
Dokumenten-ID: | 5573 |
Zusammenfassung
The fluorescence spectrum of PBN in a neat argon matrix is excitation-wavelength-dependent: at short excitation wavelengths, it consists of dual emission assigned to a charge-transfer (CT) state and a much weaker band assigned to the locally excited (LE) state. The CT emission is broad and almost completely devoid of vibrational structure, whereas the LE band is characterized by vibrationally ...
Zusammenfassung
The fluorescence spectrum of PBN in a neat argon matrix is excitation-wavelength-dependent: at short excitation wavelengths, it consists of dual emission assigned to a charge-transfer (CT) state and a much weaker band assigned to the locally excited (LE) state. The CT emission is broad and almost completely devoid of vibrational structure, whereas the LE band is characterized by vibrationally resolved emission. At long excitation wavelengths, only CT emission is obsd., indicating that the CT state is populated directly by light absorption and not via the LE state. Comparison with jet-cooled spectra of the bare mol. allows the unambiguous assignment of the LE spectrum and the location of the 0,0 band. The matrix LE emission spectrum is blue-shifted with respect to that of the gas phase, showing that the dipole moment of the LE state is smaller than that of the ground state. The fluorescence spectrum of PBN in an argon matrix does not change appreciably when acetonitrile (AN) is added to the matrix, in contrast to the case of N-phenylpyrrol (PP) (Schweke, D.; Haas, Y. J. Phys. Chem. A 2003, 107, 9554), for which addn. of AN results in the appearance of two well sepd. emission bands. The different photophys. behaviors of PP and PBN in an argon matrix (and in supersonic jets) are analyzed by a simple model that considers the restriction of large-amplitude motions in the matrix. The implications of these low-temp. studies for understanding the properties of these systems in liq. soln. are discussed.
Metadaten zuletzt geändert: 24 Mai 2018 10:11