Threshold photoionization spectra of excited solute electronic states in nonpolar liquids

Journal Article · Thu May 31 04:00:00 EDT 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100374a020· OSTI ID:6518567

Hoffman, G J; Albrecht, A C ^[1]

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1. Cornell Univ., Ithaca, NY (USA)

Photoconductivity spectra are reported for the first excited singlet (S{sub 1}) and triplet (T{sub 1}) states of N,N,N{prime},N{prime}-tetramethyl-p-phenylenediamine (TMPD) in nonpolar organic solvents at room temperature. The measured ionization potentials, corrected for the excited-state energies, agree well with those derived from previously published TMPD ground-state (S{sub 0}) photoionization studies. The excited-state spectra and the S{sub 0} spectrum both increase in magnitude with increasing excitation frequency, first exponentially and then as a power law in excess energy above the ionization threshold. This behavior is similar to that of the absorption spectra of amorphous semiconductors. In each case, direct excitation of the photodonor into the conduction band of the solvent is indicated (instead of autoionization from a superexcited state of TMPD). In one instance unambiguous evidence for this path is encountered.

• OSTI ID: 6518567
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 94:11; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
AMINES
CHEMISTRY
DATA
DATA ANALYSIS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
FLUIDS
INFORMATION
IONIZATION
LIQUIDS
MEASURING INSTRUMENTS
MEASURING METHODS
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOTOCHEMISTRY
PHOTOCONDUCTIVITY
PHOTOIONIZATION
PHYSICAL PROPERTIES