Method of quenching electronic excitation of chromophore-containing organic molecules in photoactive compositions

Abstract

The photostabilizing electronic excited state energy—particularly singlet state energy from a UV-absorbing molecule has been found to be readily transferred to (accepted by) α-cyanodiphenylacrylate compounds of formulas (I) and (V) having an alkoxy radical preferably in the four (para) position (hereinafter methoxycrylenes) on one or both of the phenyl rings: wherein at least one of Rand Ris a straight or branched chain C-Calkoxy radical, preferably C-C, more preferably C-C, and most preferably methoxy, and any non-alkoxy radical Ror Ris hydrogen; and Ris a straight or branched chain C-Calkyl radical, preferably C-C, more preferably C; wherein A and B are the same or different and are selected from the group consisting of oxygen, amino and sulfur; Rand Rare the same or different and are selected from the group consisting of C-Calkyl, C-Calkylene, C-Calkyne, C-Ccycloalkyl, C-Csubstituted alkylene, C-Csubstituted alkyne, aryl, substituted aryl, heteroaryl, heterocycloalkyl, substituted heteroaryl and substituted heterocycloalkyl; Ris selected from the group consisting of C-Calkyl, C-Calkylene, C-Calkyne, C-Ccycloalkyl, C-Csubstituted alkyl, C-Csubstituted cycloalkyl, C-Csubstituted alkylene, C-Csubstituted alkyne; R, R, Rand Rare the same or different and are selected from the group consisting of C-Calkoxy straight chin on branched and a, b, c and d are each either 0 or 1, and a, b, c and d add up to 1, 2, 3, or 4.