Three New Organic Scintillators with Large Stokes Shifts

Abstract

Three new organic scintillators (PMP-410, PMP470, and PMP480) were synthesized on the basis of 1-phenyl-3-mesityl-2-pyrazoline (PMP). Their synthesis and their polymerization in polystyrene are described. We measured their Stokes shifts in polystyrene (∼1.3 eV) between their absorption maxima (PMP-410: 287 nm; PMP-470: 315 nm; PMP-480: 314 nm) and their emission maxima (PMP-410: 408 nm; PMP-470: 480 nm; PMP-480: 479 nm). Absorption and emission maxima, Stokes shifts, and light yields of all eight pyrazoline scintillators so far synthesized are listed and are compared with results for 3-hydroxyflavone (3-HF). The advantages of these one-component dopants are discussed with respect to the usually applied two-component (scintillator plus wavelength shifter) dopants.