Organic scintillators with unusually large Stokes' shifts

Journal Article · Thu Feb 23 04:00:00 EST 1978 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100493a017· OSTI ID:5211522

Guesten, H; Schuster, P; Seitz, W

A series of methyl and/or methoxy substituted 1,3-diphenyl-2-pyrazolines were synthesized for evaluation as solutes in liquid scintillation counting systems. The electronic absorption spectra, absolute fluorescence spectra, fluorescence quantum yield, fluorescence decay times, as well as the relative pulse height of 15 1,3-diphenyl-2-pyrazolines were measured in benzene at room temperature. Unusually large Stokes' shifts with high fluorescence quantum yields of about 0.90 are obtained when bulky methyl and/or methoxy substituents are attached in ortho, ortho' positions of the phenyl rings in 1 and/or 3 positions of the 2-pyrazoline ring. The sterically hindered 1,3-diphenyl-2-pyrazolines have a promising potential as scintillators for liquid scintillation counting. Due to the large Stokes' shift the highly soluble sterically hindered 1,3-diphenyl-2-pyrazolines can be used as primary solutes without requiring a wavelength shifter.

• Research Organization: Kernforschungszentrum, Karlsruhe, Ger.
• OSTI ID: 5211522
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 82:4; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400103* -- Radiometric & Radiochemical Procedures-- (-1987)
ABSORPTION SPECTRA
AZOLES
COUNTING TECHNIQUES
DE-EXCITATION
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EVALUATION
HETEROCYCLIC COMPOUNDS
LIQUID SCINTILLATORS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORS
PYRAZOLES
PYRAZOLINES
RADIATIONLESS DECAY
SCINTILLATION COUNTING
SPECTRA