Amino-acyl-quinoxalinone yellow dyes are cyclised analogues of the yellow azomethine dyes developed for, and still used in, silver halide colour photography. Unlike image azomethine dyes, which are rapidly deactivated in their excited states by torsion about the azomethine bond, amino-acyl-quinoxalinone dyes have an interesting photophysics because torsion is not possible due to their cyclised structure. We report results from studies on singlet and triplet state properties, and singlet oxygen yields, of the yellow dye, 7-diethylamino-3-(2,2-dimethyl-propionyl)-5-methyl-1-phenyl-1H-quinoxalin-2-one, in polar and nonpolar solvents. The dye photophysics is characterised by a weak fluorescence, with a solvent dependent emission yield (ΦF ≈ 0.002-0.004), and short singlet state lifetime (τexpt ≈ 20-50 ps), both increasing by a factor of ≈2 in going from polar acetonitrile to non-polar dioxane as solvent. DFT ZINDO calculations show a transition involving significant electron transfer from the diethyl-amino group into the carbonyl region of the molecule. In solution, in the presence of oxygen, the triplet state decays almost exclusively by oxygen quenching, and singlet oxygen is produced in high yield (Φ∆ ≈ 0.5-0.55). The triplet state absorbs across the 450-750 nm region with maxima around 480 and 650 nm, and moderate molar absorption coefficients (ca. 6000-8000 M-1 cm-1). In a glass at 77 K, triplet decay gives a red phosphorescence, with λmax ≈ 640-650 nm, and a  ≈ 0.25 s lifetime. If singlet oxygen yields are a good indication of triplet yields, then internal conversion and intersystem crossing occur with roughly equal efficiency.

中文翻译：

---

氨基-酰基-喹喔啉酮黄色染料的单线态和三线态性质和单线态氧产率。

氨基-酰基-喹喔啉酮黄色染料是黄色偶氮甲碱染料的环化类似物，是为卤化银彩色摄影而开发并仍在使用。与图像偶氮甲碱染料不同，它们在激发态下会通过围绕偶氮甲碱键的扭转而迅速失活，而氨基-酰基-喹喔啉酮染料具有有趣的光物理学，因为由于其环化结构，不可能发生扭转。我们报告了黄色染料 7-diethylamino-3-(2,2-dimethyl-propionyl)-5-methyl-1-phenyl-1H-quinoxalin-的单线态和三线态性质以及单线态氧产率的研究结果。 2-1，在极性和非极性溶剂中。染料光物理的特点是荧光弱，具有溶剂依赖的发射产率（ΦF ≈ 0.002-0.004）和短的单线态寿命（τexpt ≈ 20-50 ps），从极性乙腈到非极性二恶烷作为溶剂，两者都增加了 ≈2 倍。DFT ZINDO 计算显示了从二乙基氨基到分子羰基区域的显着电子转移。在溶液中，在有氧的情况下，三线态几乎完全通过氧猝灭而衰变，并且单线态氧以高产率产生（Φ∆ ≈ 0.5-0.55）。三重态在 450-750 nm 区域吸收，最大值在 480 和 650 nm 附近，摩尔吸收系数适中（约 6000-8000 M-1 cm-1）。在 77 K 的玻璃中，三重态衰变产生红色磷光，λmax ≈ 640-650 nm，寿命 ≈ 0.25 s。如果单线态氧产率是三线态产率的良好指示，则内部转化和系统间交叉以大致相等的效率发生。