Wetzler Diana E, García-Fresnadillo David, Orellana Guillermo
Laboratory of Applied Photochemistry, Department of Organic Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, Spain.
Phys Chem Chem Phys. 2006 May 21;8(19):2249-56. doi: 10.1039/b517756a. Epub 2006 Mar 16.
Generation of singlet molecular oxygen ((1)O(2)) by photosensitization with methylene blue (MB) supported in Nafion-Na films has been quantified by integration of the (1)O(2) emission decay at 1270 nm. The quantum yield of (1)O(2) production (Phi(Delta)) in the air-equilibrated solid phase is 0.24 +/- 0.03. Information on the (1)O(2) generation environment has been gained from complementary techniques such as UV-Vis absorption and emission spectroscopy, as well as MB fluorescence and triplet-triplet absorption decay. Results are compared with the (1)O(2) generation by MB in methanol solution (Phi(Delta) = 0.51) and in methanol-swollen Nafion films (Phi(Delta) = 0.49 +/- 0.06). Differences and similarities are discussed in terms of the factors that influence Phi(Delta) in solution and in the solid media. The optical and mechanical features of Nafion, ease of dye loading, compatibility with most solvents, homogeneity, reproducibility and stability of the photosensitizing material makes it a convenient reference for (1)O(2) generation quantum yield measurements in transparent (micro)heterogeneous and homogeneous media.
通过对1270nm处单线态分子氧（(1)O(2)）发射衰减进行积分，对负载在Nafion-Na膜中的亚甲蓝（MB）光敏化产生单线态分子氧((1)O(2))的过程进行了定量。在空气平衡的固相中产(1)O(2)的量子产率（Phi(Delta)）为0.24±0.03。通过紫外可见吸收和发射光谱、MB荧光以及三重态-三重态吸收衰减等互补技术，获得了有关(1)O(2)产生环境的信息。将结果与MB在甲醇溶液（Phi(Delta)=0.51）和甲醇溶胀的Nafion膜（Phi(Delta)=0.49±0.06）中产生(1)O(2)的情况进行了比较。根据影响溶液和固体介质中Phi(Delta)的因素，讨论了差异和相似之处。Nafion的光学和机械特性、染料加载的便利性、与大多数溶剂的兼容性、光敏材料的均匀性、可重复性和稳定性，使其成为在透明（微）非均相和均相介质中进行(1)O(2)产生量子产率测量的方便参考。
