Amplification of luminescence of stable radicals by coordination to NHC-gold(I) complex.

The luminescence of stable radicals can be enhanced by coordination to metal complexes. The 4% fluorescence quantum yield of (3,5-difluoro-4-pyridyl)bis(2,4,6-trichlorophenyl)methyl radical (F 2 PyBTM) in dichloromethane was enhanced up to 36% by coordination to Au I with N -heterocyclic carbene ligand, which is a record for metal-radical complexes.