Diphosphine-induced chiral propeller arrangement of gold nanoclusters for singlet oxygen photogeneration
gold nanoclusters, Au13, chirality, singlet oxygen, synchrotron radiation X-ray diffraction (XRD)
ABSTRACT In this study, 1,2-bis(diphenylphosphino)ethane (dppe) ligands are used to synthesize gold nanoclusters with an icosahedral Au13 core. The nanoclusters are characterized and formulated as [Au13(dppe)5Cl2]Cl3 using synchrotron radiation X-ray diffraction, UV/Vis absorption spectroscopy, electrospray ionization mass spectrometry, and density functional theory (DFT) calculations. The bidentate feature of dppe ligands and the positions of coordinating surface gold atoms induce a helical arrangement that forms a propeller-like structure, which reduces the symmetry of the gold nanocluster to C1. Therefore, dppe ligands perform as a directing agent to create chiral an ansa metallamacrocycle [Au13(dppe)5Cl2]3+ nanocluster, as confirmed by simulated electronic circular dichroism spectrum. The highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap of the [Au13(dppe)5Cl2]3+ cluster is determined as approx. 1.9 eV, and further confirmed by ultraviolet photoemission spectroscopy analysis and DFT simulation. Furthermore, the photoactivity of [Au13(dppe)5Cl2]3+ is investigated, with the nanocluster shown to possess near-infrared photoluminescence properties, which can be employed for 1O2 photogeneration. The quantum yield of 1O2 photogeneration using the [Au13(dppe)5Cl2]3+ nanocluster is up to 0.71, which is considerably higher than those of anthracene (an organic dye), and Au25 and Au38 nanoclusters.
Tsinghua University Press
Jiangwei Zhang,Yang Zhou,Kai Zheng,Hadi Abroshan,Douglas R. Kauffman,Junliang Sun,Gao Li, Diphosphine-induced chiral propeller arrangement of gold nanoclusters for singlet oxygen photogeneration. NanoRes.2018, 11(11): 5787–5798