%0 Journal Article %A Cagan, David A. %A Garcia, Arman C. %A Li, Kin %A Ashen-Garry, David %A Tadle, Abegail C. %A Zhang, Dong %A Nelms, Katherine J. %A Liu, Yangyang %A Shallenberger, Jeffrey R. %A Stapleton, Joshua J. %A Selke, Matthias %D 2018 %T Chemistry of Singlet Oxygen with a Cadmium–Sulfur Cluster: Physical Quenching versus Photooxidation %U https://acs.figshare.com/articles/journal_contribution/Chemistry_of_Singlet_Oxygen_with_a_Cadmium_Sulfur_Cluster_Physical_Quenching_versus_Photooxidation/7525052 %R 10.1021/jacs.8b10516.s001 %2 https://acs.figshare.com/ndownloader/files/13992920 %K SPh %K nanoparticle %K singlet oxygen generation %K singlet oxygen quenching rate constants %K 4 N %K Cd 4 %K 1 O 2 removal %K quantum %K CD 3 OD %K singlet oxygen %K cluster %K cadmium %K dot %K Physical %X We investigated the chemistry of singlet oxygen with a cadmium–sulfur cluster, (Me4N)2[Cd4(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[Cd4(SPh)10] is indeed a very strong quencher of singlet oxygen with total rate constants for 1O2 removal of (5.8 ± 1.3) × 108 M–1 s–1 in acetonitrile and (1.2 ± 0.5) × 108 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) × 106 M–1 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. %I ACS Publications