4-Cyanocoumarin derivatives which have a distinct sensitivity to visible
light, distinct luminescent ability, and satisfactory applicability for
photochemical polymerization, dye lasers, and organic electroluminescent
elements. Since most of the derivatives have a fluorescent maximum
wavelength of 600 to 650 nm, particularly, 610 to 630 nm, they are
extremely useful as luminescent agents for organic EL elements which emit
visible light in a red-color region, and can be quite useful as
luminescent agents in organic EL elements and laser-active substances in
dye lasers, as well as luminous bodies as lighting sources for lighting
devices, and information displays for visually displaying information.