Four crystalline (pseudo)polymorphs of [Ph–Au–CN–Ph_ip–OC₈H₁₇] (1), where Ph_ip = central phenylene of pentiptycene, reveal that the π-backbone conformation relative to the Au⋯Au bonding axis is important in determining the energy and efficiency of the supramolecular luminescence, which offers mechanistic insights into the luminescence mechanochromism and vapochromism and the solvent-dependent aggregation-induced emission (AIE) of 1.