Independent Control of Singlet Oxygen and Radical Generation via Irradiation of a Two-Color Photosensitive Molecule
Independent Control of Singlet Oxygen and Radical Generation via Irradiation of a Two-Color Photosensitive Molecule
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DOI：
10.1021/acs.macromol.9b00424
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发表时间：
2019-07-09
期刊：
影响因子：
5.5
通讯作者：
Stansbury, Jeffrey W.
中科院分区：
文献类型：
--
作者：
Childress, Kimberly K.;Kim, Kangmin;Stansbury, Jeffrey W.
自由基聚合用于广泛的应用，但受到氧气存在的负面影响。酞菁锌先前已被用作单线态氧发生剂，以在光引发剂的光激发之前将消耗自由基的基态三线态氧激发成其反应性较低的单线态。首次报道了酞菁紫外吸收带的辐照可以实现聚合反应，而光敏化和光引发反应可以通过酞菁两个不同吸收带的辐照来独立实现，从而减少氧阻聚，引发聚合反应，而不需要额外的处理。我们提出了一种机制，这种独特的光引发现象，并通过计算和实验方法验证其可行性。这类新的双光敏分子在受氧存在不利影响的应用中显示出有前途的实用性，例如涂层和立体光刻。
Free-radical polymerizations are used for a wide range of applications but are detrimentally impacted by the presence of oxygen. Zinc phthalocyanines have been previously used as singlet oxygen generators to excite radical-consuming ground-state triplet oxygen into its less reactive singlet state prior to photoexcitation of a photoinitiator. We report for the first time that polymerization can be achieved via irradiation of UV band of phthalocyanine and that photosensitization and photoinitiation can be independently achieved via irradiation of its two distinct absorption bands to reduce oxygen inhibition and initiate polymerization without the need for additional treatment. We propose a mechanism for this unique photoinitiation phenomenon and verify its feasibility via computational and experimental approaches. This new class of dual-photosensitive molecules shows promising utility in applications that are adversely impacted by the presence of oxygen, such as coatings and stereolithography.