Chemistry of Singlet Oxygen with a Cadmium-Sulfur Cluster: Physical Quenching versus Photooxidation
Chemistry of Singlet Oxygen with a Cadmium-Sulfur Cluster: Physical Quenching versus Photooxidation
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DOI：
10.1021/jacs.8b10516
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发表时间：
2019-01-09
影响因子：
15
通讯作者：
Selke, Matthias
中科院分区：
文献类型：
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作者：
Cagan, David A.;Garcia, Arman C.;Selke, Matthias
我们研究了单重态氧与镉硫簇（Me4N）(2)[Cd-4(SPh)(10)]的化学性质。该簇被用作镉硫纳米颗粒的模型。这种纳米颗粒通常与光敏剂（用于单线态氧生成或染料敏化太阳能电池）一起使用，因此，确定镉硫部分是否与单线态氧发生物理猝灭和/或化学反应是很重要的。我们发现（Me4N）(2)[Cd-4(SPh)(10)]确实是一种非常强的单重态氧猝灭剂，对O-1(2)去除乙腈中的（5.8 +/- 1.3）× 10(8) M-1和CD3OD中的（1.2 +/- 0.5）× 10(8) M-1 s（-1）的总速率常数。物理猝灭占主导地位，但导致簇分解和亚硫酸盐形成的化学反应也很重要，在甲醇中的速率常数为（4.1 +/- 0.6）x 10(6) s（-1）。基于量子点的摩尔浓度，市售的镉硫量子点（lumidots）显示出类似的单线态氧猝灭速率常数。
We investigated the chemistry of singlet oxygen with a cadmium-sulfur cluster, (Me4N)(2)[Cd-4(SPh)(10)]. This cluster was used as a model for cadmium-sulfur nanoparticles. Such nanoparticles are often used in conjunction with photosensitizers (for singlet oxygen generation or dye-sensitized solar cells), and hence, it is important to determine if cadmium-sulfur moieties physically quench and/or chemically react with singlet oxygen. We found that (Me4N)(2)[Cd-4(SPh)(10)] is indeed a very strong quencher of singlet oxygen with total rate constants for O-1(2) removal of (5.8 +/- 1.3) x 10(8) M-1 in acetonitrile and (1.2 +/- 0.5) X 10(8) M-1 s(-1) in CD3OD. Physical quenching predominates, but chemical reaction leading to decomposition of the cluster and formation of sulfinate is also significant, with a rate constant of (4.1 +/- 0.6) x 10(6) s(-1) in methanol. Commercially available cadmium-sulfur quantum dots ("lumidots") show similar singlet oxygen quenching rate constants, based on the molar concentration of the quantum dots.