Structure, lasing characteristics, and photostability of new heteroarylcoumarins

A series of 7-diethylaminocoumarins containing various bulky substituents in the form of heterocyclic radicals is investigated under conditions of nanosecond coherent pumping by radiation from an electric-discharge excimer XeCl laser, as well as under conditions of microsecond laser excitation by a dye conversion laser and lamp pumping. The influence of these substituents and the aryl fragment in the structure of the coumarin molecule on the spectral and lasing characteristics of new coumarins is established. It is experimentally shown that triazole and oxadiazole heterocycles are preferable substituents from the point of view of improving the lasing capability and photostability of the starting compounds. Modification of the molecular structure of the initial 7-diethylaminocoumarins and julolidinecoumarins by adding bulk heterocyclic radicals at position 3 makes it possible to obtain new laser media that generate radiation in the spectral range of 490–560 nm and possess a sufficiently high lasing efficiency and photostability under various excitation conditions.