TY - JOUR
T1 - Chemistry of Singlet Oxygen with a Cadmium-Sulfur Cluster
T2 - Physical Quenching versus Photooxidation
AU - Cagan, David A.
AU - Garcia, Arman C.
AU - Li, Kin
AU - Ashen-Garry, David
AU - Tadle, Abegail C.
AU - Zhang, Dong
AU - Nelms, Katherine J.
AU - Liu, Yangyang
AU - Shallenberger, Jeffrey R.
AU - Stapleton, Joshua J.
AU - Selke, Matthias
N1 - Funding Information:
The authors gratefully acknowledge support from the NSF-PREM program (DRM-1523588). A.C.G. and M.S. acknowledge support from the NSF-CREST program (DRM-1547723), and D.A.C. acknowledges support from the NIH-NIGMS MARC program (T34 GM08228). The authors thank Dr. Nichole Wonderling (The Pennsylvania State University) for assistance with the PXRD spectra.
Publisher Copyright:
© 2018 American Chemical Society.
PY - 2019/1/9
Y1 - 2019/1/9
N2 - We investigated the chemistry of singlet oxygen with a cadmium-sulfur cluster, (Me 4 N) 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 (Me 4 N) 2 [Cd 4 (SPh) 10 ] is indeed a very strong quencher of singlet oxygen with total rate constants for 1 O 2 removal of (5.8 ± 1.3) × 10 8 M -1 s -1 in acetonitrile and (1.2 ± 0.5) × 10 8 M -1 s -1 in CD 3 OD. 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 6 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.
AB - We investigated the chemistry of singlet oxygen with a cadmium-sulfur cluster, (Me 4 N) 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 (Me 4 N) 2 [Cd 4 (SPh) 10 ] is indeed a very strong quencher of singlet oxygen with total rate constants for 1 O 2 removal of (5.8 ± 1.3) × 10 8 M -1 s -1 in acetonitrile and (1.2 ± 0.5) × 10 8 M -1 s -1 in CD 3 OD. 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 6 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.
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U2 - 10.1021/jacs.8b10516
DO - 10.1021/jacs.8b10516
M3 - Article
C2 - 30575375
AN - SCOPUS:85059847397
SN - 0002-7863
VL - 141
SP - 67
EP - 71
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 1
ER -