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Four polymorphic forms of the complex Zn[Au(CN)₂]₂ have been synthesized and both structurally and spectroscopically characterized. In each of the four polymorphs, a zinc center in a tetrahedral geometry with a Au(CN)₂⁻ unit at each tetrahedral vertex is observed. All four structures contain three-dimensional networks based on corner-sharing tetrahedra. Because of the long Au(CN)₂⁻ bridging unit, the extra space not occupied by one network is filled by two to five additional interpenetrated networks. Short gold−gold bonds with lengths ranging from 3.11 to 3.33 Å hold the interpenetrated networks together. Three of the four polymorphs are luminescent, having solid-state emissions with wavelengths ranging from 390 to 480 nm. A linear correlation between the emission energy and the gold−gold distance was observed. Upon exposure to ammonia vapor, the polymers altered their structures and emission …