SYNTHESES AND PHOTOPHYSICAL PROPERTIES OF FLUORESCENT 2-ARYL-3-HYDROXY-4-CHROMENONES

The particle detectors proposed for the Super-conducting Super Collide r contain polystyrene scintillation fibers as a component. Scintillati on fluors soluble in styrene are required which have improved light ou tput and response time. New 2-aryl-3-hydroxy-4-chromenones related to 3-hydroxyflavone were prepared which displayed these improved properti es. Improved solvent systems for chromenone formation were essential i n the synthesis of two of the chromenones. One chromenone produced flu orescence emission at 560 nm with a quantum yield of 0.53 and a scinti llation decay time of 5 nsec.