The dinuclear complex [[Tl(eta6-toluene)][Au(C6Cl5)2]] (1) displays very intense blue phosphorescence and a rigidochromic behavior in the solid state. The photophysical measurements in a glassy solution display an oligomerization process via metal-metal interactions. Density functional theory calculations show a distortion of the aurate-thallium T shape in the lowest triplet excited state, leading to a triplet metal-to-metal charge-transfer state.