使用4-羥基香豆素衍生物10和1-甲基喹啉碘鹽18有效合成一個氧氮二環化合物5a，並探討其螢光氧化還原開關性質，結果顯示開環的化合物5b螢光強度明顯減少，而經氧化開環化合物可以迅速恢復到原來的合環形式5a，此開環與閉環之轉換可視為一種潛在雙穩態系統螢光氧化還原開關。
另，2-甲醛基-4-羥基香豆素19與喹啉碘鹽15反應，接著使用硼氫化鈉還原亦可快速得到香豆素與啡啶耦合雜環化合物及螺吡喃衍生物6a，前者具有氧化還原開關性質，後者若經適當修飾，有機會成為潛在之光致變色物。 An oxazabicycle derivative 5a was efficiently synthesized by coupling of 7-dimethylamino-4-hydroxycoumarin 10 with N-methyl-2-phenylquinolinium iodide 18 and to investigate its fluorescence redox-switching properties. Chemical reduction of this strongly fluorescent oxazabicycle results in the ring-opened product with a distinct decrease in emission intensity. The resulting ring-opened species can be swiftly reverted to the original ring-closed forms by DDQ oxidation. A novel coumarin and phenanthridine-fused heterocycle and an oxazaspiropyran derivative 6a were also prepared by first base-mediated condensation of coumarins 19 and N-methylquinolinium salts 15, and followed by sodium borohydride reduction. The former was found to possess redox switching properties; the later, with suitable modifications, may have the potential to function as a photochromic colorant.
