Spin-multiplicity is an important factor for luminescent compounds, because it affects rates of non-radiative, fluorescent, or phosphorescent transitions. Luminescence of monoradicals with ground and excited doublet states attracts much interests recently; however, monoradical molecules had problem in their stability under photoirradiation. We have recently reported a novel luminescent organic radical, (3,5-dichloro-4-pyridyl)bis(2,4,6-trichlorophenyl) methyl radical (PyBTM), which shows greater photostability than that of tris(2,4,6-trichlorophenyl)methyl radical (Angew. Chem. Int. Ed. 2014, DOI: 10.1002/anie.201407362). In this study, we aimed to control the properties of PyBTM using coordination chemistry. A gold(I) complex with coordinated PyBTM was synthesized, and single crystal X-ray diffraction, ESR spectrum, cyclic voltammogram, and results of DFT-calculation were investigated. The absorption and emission spectra showed bathochromic shifts from those of PyBTM. This is the first example of a luminescent metal complex that contains a luminescent radical as a ligand, as far as we know. The fluorescence quantum yield of the Au(I) complex in dichloromethane was higher than that of PyBTM, due to the longer fluorescence lifetime and the faster rate of the fluorescence transition.

Fluorescence of a gold(I) complex with a stable fluorescent organic radical ligand

249th National Meeting (2015)

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