Luminescence in Phosphine-Stabilized Copper Chalcogenide Cluster Molecules鈥擜 Comparative Study
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- 作者：Andreas Eichh枚fer ; Gernot Buth ; Sergei Lebedkin ; Michael K眉hn ; Florian Weigend
- 刊名：Inorganic Chemistry
- 出版年：2015
- 出版时间：October 5, 2015
- 年：2015
- 卷：54
- 期：19
- 页码：9413-9422
- 全文大小：537K
- ISSN：1520-510X
文摘
The electronic properties of a series of eight copper chalcogenide clusters including [Cu12S6(dpppt)4] (dpppt = Ph2P(CH2)5PPh2), [Cu12Se6(dppo)4] (dppo = Ph2P(CH2)8PPh2), [Cu12S6(dppf)4] (dppf = Ph2PCpFeCpPPh2), [Cu12S6(PPh2Et)8], [Cu12S6(PEt3)8], [Cu24S12(PEt2Ph)12], [Cu20S10(PPh3)8], and [Cu20S10(PtBu3)8] were investigated by absorption and photoluminescence (PL) spectroscopy as well as time-dependent density functional theory calculations. Major features of the experimental electronic absorption spectra are generally well-reproduced by the spectra simulated from the calculated singlet transitions. Visualization of the nonrelaxed difference densities indicates that for all compounds transitions at higher energies (above 鈭?.5 eV, i.e., below 鈭?95 nm) predominantly involve excitations of electrons from orbitals of the cluster core to ligand orbitals. Conversely, the natures of the lower-energy transitions are found to be highly sensitive to the specifics of the ligand surface. Bright red PL (centered at 鈭?50鈥?00 nm) in the solid state at ambient temperature is found for complexes with all 鈥楥u12S6鈥?(E = S, Se) cores as well as the dimeric 鈥楥u24S12鈥? although in [Cu12S6(dppf)4], the PL appears to be efficiently quenched by the ferrocenyl groups. Of the two isomeric 鈥楥u20S10鈥?complexes the prolate cluster [Cu20S10(PPh3)8] shows a broad emission that is centered at 鈭?20 nm, whereas the oblate cluster [Cu20S10(PtBu3)8] displays a relatively weak orange emission at 鈭?75 nm. The emission of all complexes decays on the time scale of a few microseconds at ambient temperature. A very high photostability is quantitatively estimated for the representative complex [Cu12S6(dpppt)4] under anaerobic conditions.