Photoluminescence of silver(I) and gold(I) cyanide 1D coordination polymers

► TD-DFT studies of MCN (M = Ag, Au) model chains show that the absorption spectrum arises from π-π, rather than HOMO-LUMO, excitations. ► The DFT S0-T gaps of MCN model chains agree with the emission spectra of the bulk MCN materials. ► Trends in the molecular properties of MCN are attributed to relativistic effects on Au.