Reinecke’s salt is a chemical compound with the formula NH4[Cr(NCS)4(NH3)2]·H2O. The dark-red crystalline compound is soluble in boiling water, acetone, and ethanol. The chromium atom is surrounded by six nitrogen atoms in an octahedral geometry. The NH3 ligands are mutually trans and the Cr–NCS groups are linear. The salt crystallizes with one molecule of water.