Abstract: The disclosure relates to a substituted cyclooctatetraene triplet excited-state quencher compound of Formula (I): wherein: Z is a wide band gap moiety; L is a non-conjugating linker group; each R, which may be the same or different, is a non-conjugating substituent; n is an integer from 0 to 7; and m is an integer from 1 to 6. The disclosure further relates to use of such compounds as triplet quenchers, compositions comprising such compounds, films or coatings comprising said compounds or compositions, and use of said compositions or films or coatings as active gain media for light amplification.

Abstract: A compound of the formula (1) exhibits high photoluminescence quantum yields, high radiative decay constant and low ASE thresholds from solution-processed neat and blend films. Ar1 and Ar2 are aryl groups, L is a divalent group having a group of the formula (2), and R is H or a diarylamino group. At least one alkyl group having at least five carbon atoms which are bonded is present in the formula (1).