Department of Chemistry and Biochemistry , California State University , Los Angeles , California 90032 , United States.
Materials Characterization Laboratory , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States.
J Am Chem Soc. 2019 Jan 9;141(1):67-71. doi: 10.1021/jacs.8b10516. Epub 2018 Dec 27.
We investigated the chemistry of singlet oxygen with a cadmium-sulfur cluster, (MeN)[Cd(SPh)]. 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 (MeN)[Cd(SPh)] is indeed a very strong quencher of singlet oxygen with total rate constants for O removal of (5.8 ± 1.3) × 10 M s in acetonitrile and (1.2 ± 0.5) × 10 M s in CDOD. 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) × 10 M s 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.
我们研究了单线态氧与硫化镉簇（MeN）[Cd（SPh）]的化学性质。该簇被用作硫化镉纳米粒子的模型。这些纳米粒子通常与光敏剂一起使用（用于生成单线态氧或染料敏化太阳能电池），因此，确定镉硫部分是否会与单线态氧物理猝灭和/或化学反应非常重要。我们发现（MeN）[Cd（SPh）]确实是单线态氧的非常强猝灭剂，在乙腈中的总 O 去除速率常数为（5.8±1.3）×10^5 M s^-1，在 CDOD 中的为（1.2±0.5）×10^5 M s^-1。物理猝灭占主导地位，但导致簇分解并形成亚硫酸盐的化学反应也很重要，在甲醇中的速率常数为（4.1±0.6）×10^5 M s^-1。根据量子点的摩尔浓度，商业上可获得的硫化镉量子点（“lumidots”）表现出相似的单线态氧猝灭速率常数。
