Crystallographic and luminescence studies on salts of the two-coordinate carbene cation, [Au{C(NHCH₃)(NHCH₂CH₂OH)}₂]⁺, demonstrate the ability of the cation to exist in three different states of aggregation. In colorless, non-luminescent [Au{C(NHCH₃)(NHCH₂CH₂OH)}₂]Cl the cation crystallizes as a monomer with the nearest gold(I) center 6.7890(11) Å away. Colorless, luminescent [Au{C(NHCH₃)(NHCH₂CH₂OH)}₂]AsF₆ forms dimers with an Au⋯Au separation of 3.1288(4) Å. These dimers form weakly associated extended chains of cations with additional Au⋯Au separations of 3.6625(5) Å. [Au{C(NHCH₃)(NHCH₂CH₂OH)}₂]PF₆ is isostructural. Yellow, luminescent [Au{C(NHCH₃)(NHCH₂CH₂OH)}₂]₃(AsF₆)₂Cl·0.5(H₂O)₂ and [Au{C(NHCH₃)(NHCH₂CH₂OH)}₂]₃(PF₆)₂Cl·0.5(H₂O)₂ form trimers that further aggregate into extended chains with rather short Au⋯Au separations of 3.1301(14) Å, 3.1569(14) Å and 3.1415(14) Å. Absorption, emission and excitation spectra are reported for these salts. The excitation and emission results from the interactions between the gold centers and involves transitions between the filled d_z² band and the empty p_z bands with the z axis pointing along the chain of cations.