Photoionization yield and electron thermalization range spectra of N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) in tetramethylsilane

Journal Article · Mon Apr 15 04:00:00 EST 1985 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.448900· OSTI ID:5824985

Lee, K; Lipsky, S

The fractional change in the fluorescence yield psi/sub F/ of TMPD in tetramethylsilane, due to imposition of an electric field of strength E = 45.6 kV/cm, has been determined at 44 discrete excitation energies, epsilon, above the photoionization threshold from epsilon = 4.77 to 7.52 eV. Two maxima are clearly resolved in the field quenching ratio, (..delta..psi/sub F//psi/sub F//sup 0/)/sub E/, one at 5.71 eV and the other at 6.79 eV. Beyond 7.0 eV, (..delta..psi/sub F//psi/sub F//sup 0/)/sub E/ is again observed to slowly increase. For each of 12 of the previous excitation energies, (..delta..psi/sub F//psi/sub F//sup 0/)/sub E/ was obtained as a function of E from 18.2 to 45.6 kV/cm. Using an exponential radial distribution function of geminate pair separation distances, f(r) = ..beta../sup 3/e/sup -betar//2, the field dependence was fitted to the Onsager theory and the average electron thermalization range, = 3/..beta.. extracted as a function epsilon. With this, the yield of thermalized electrons, phi/sub plus-or-minus/ was also obtained as a function of epsilon. The range spectrum is found to increase with increasing epsilon with an inflection at 5.9 eV, followed by a rapid rise to a maximum of 230 A at 6.7 eV and then to decline continuously to 167 A at 7.5 eV. The photoionization yield spectrum shows two maxima, one at 5.7 eV with phi/sub plus-or-minus/ = 0.44 and a second at 6.9 eV with phi/sub plus-or-minus/ = 0.52. Beyond 7.0 eV, phi/sub plus-or-minus/ increases to 0.57 at epsilon = 7.5 eV.

• Research Organization: Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
• OSTI ID: 5824985
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 82:8; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
CHEMISTRY
ELECTRIC FIELDS
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
FLUORESCENCE
ION PAIRS
IONIZATION
LEPTONS
LUMINESCENCE
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMISTRY
PHOTOIONIZATION
RANGE
SLOWING-DOWN
THERMALIZATION