Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstraße 15, 76131, Karlsruhe, Germany.
Institute of Physical Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 2, 76131, Karlsruhe, Germany.
Chemistry. 2023 Jun 2;29(31):e202300497. doi: 10.1002/chem.202300497. Epub 2023 Apr 21.
A coumarin functionalized aminodiphosphine has been introduced as a bidentate ligand in coinage metal chemistry. Mono-, di-, and trimetallic copper and silver complexes were synthesized with this ligand. The hybrid character of the ligand led to compounds with rich luminescence properties. These include coumarin-based blue fluorescence, observed as a sole emission in solution at room temperature, and green phosphorescence, which is efficient at low temperatures and dominates the spectra of the metal complexes. In the rigid environment of frozen solutions, the green phosphorescence shows an unusually long (for metal complexes) decay on the seconds timescale in high quantum yield. In addition, a red phosphorescence, which may be assigned to the triplet state localized in the phosphine-M Cl (M=Cu, Ag), is observed for the trinuclear complexes at low temperature. Neither the second-long phosphorescence nor the red emission is observed for the coumarin ligand, thus they must be a result of the coordination to coinage metal clusters. The excited states in these compounds were also investigated by femtosecond transient absorption spectroscopy and quantum chemical calculations.
一种香豆素功能化的双齿膦配体已被引入到金属化学中。使用该配体合成了单、二价和三价铜和银配合物。配体的混合特性导致化合物具有丰富的发光性质。这些性质包括香豆素基的蓝色荧光，在室温下在溶液中观察到唯一的发射，以及在低温下效率较高的绿色磷光，在金属配合物的光谱中占主导地位。在冻结溶液的刚性环境中，绿色磷光在高量子产率下以秒为单位的时间尺度上表现出异常长的衰减（对于金属配合物而言）。此外，对于三核配合物，在低温下观察到红色磷光，其可能归因于位于膦-M Cl（M=Cu，Ag）中的三重态局域化。对于香豆素配体，既没有观察到第二个长磷光，也没有观察到红色发射，因此它们必须是与金属簇配位的结果。通过飞秒瞬态吸收光谱和量子化学计算研究了这些化合物中的激发态。
