Ligand Based Dual Fluorescence and Phosphorescence Emission from BODIPY Platinum Complexes and Its Application to Ratiometric Singlet Oxygen Detection
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- 作者：Fabian Geist ; Andrej Jackel ; Rainer F. Winter
- 刊名：Inorganic Chemistry
- 出版年：2015
- 出版时间：November 16, 2015
- 年：2015
- 卷：54
- 期：22
- 页码：10946-10957
- 全文大小：604K
- ISSN：1520-510X
文摘
Four new 4,4-difluoro-4-bora-3a,4a-diaza-s-indacen-8-yl (BODIPY) platinum(II) complexes of the type cis-/trans-Pt(BODIPY)Br(PR3)2 (R = Et or Ph) were synthesized and characterized by NMR, electronic absorption, and luminescence spectroscopy. Three of the complexes were also studied by single crystal X-ray diffraction. The absorption profiles of the four complexes feature intense HOMO 鈫?LUMO 蟺 鈫?蟺* transitions with molar extinction coefficients 蔚 of ca. 50鈥?00 M鈥?cm鈥? at around 475 nm and vibrational progressions that are characteristic of BODIPYs. Most remarkably, most complexes exhibit dual emissions through fluorescence at ca. 490 nm and phosphorescence at ca. 650 nm that originate from Pt-perturbed BODIPY-centered 1蟺蟺* or 3蟺蟺* states, respectively. Electronic absorption and luminescence spectroscopy data are in good agreement with our TD-DFT calculations. While the emission of the cis-complexes is dominated by fluorescence, their trans-isomers emit predominantly through phosphorescence with a phosphorescence quantum yield for trans-Pt(BODIPY)Br(PEt3)2 (trans-1) of 31.2%. trans-1 allows for ratiometric one-component oxygen sensing in fluid solution up to atmospheric concentration levels and exhibits a remarkably high Stern鈥揤olmer constant for the quenching of the excited triplet state by oxygen of ca. 350 bar鈥? as determined by changes in phosphorescence intensity and lifetime.