Highly efficient blue-green delayed fluorescence from copper(I) thiolate complexes: luminescence color alteration by orientation change of the aryl ring.

Highly emissive three-coordinate thiolate copper(I) complexes are synthesized and characterized. The Cu(I) complexes emit intense blue-green delayed fluorescence with high photoluminescence quantum yields of approximately 1.0 at both 293 K and 77 K in the solid state, whereas orange emission at 293 K in solution is observed.