Beyond a T-shape.

Varying the steric bulk of either the phosphine or the halide in Au(PR3)2X complexes allows intuitive tuning of the phosphorescence energy to multiple visible colors, including the coveted blue for LED applications. The excited-state structure involves distortion of the trigonal coordination sphere beyond a T-shape. The [Au(TPA)2]Cl complex exhibits orange phosphorescence due to exciplex formation with the counterion to form the same type of excited state, representing the first example of a luminescent two-coordinate Au(I) complex in absence of both Au...Au interactions and aromatic moieties.