New Insights into the Effects of Self-Association of the Cation [Au{C(NHMe)₂}₂]⁺ on Its Solid State Structure and Luminescence

Colorless [Au{C(NHMe)2}2]X·H2O (X = Cl or Br) crystallize as dimers with Au···Au separations of 3.1231(3) Å (Cl salt) and 3.1297(4) Å (Br salt) between the linear, two-coordinate cations, and there is no direct interaction of Au(I) with the halide ions which are hydrogen bonded to ligand N−H groups and the water molecules. The luminescence of these dimers occurs at higher energy than that observed in extended chains of the same cation in the corresponding (PF6)- and (BF4)- salts and shows the important effects of aggregation on the observed luminescence.