Two new coordination polymers have been assembled using the chromato ions as bridging ligands: 1 ∞ [Ni(phen)(H 2 O) 2 (μ-O 2 CrO 2 )] 1, and 3 ∞ [Mn(4,4′-bipy)(H 2 O)(μ-O 3 CrO)]·H 2 O 2. In crystal 1 the chromate ions act as bridges connecting two nickel ions through two oxygen atoms, resulting in infinite chains. 1,10-Phenanthroline acts as a blocking ligand. In compound 2, each chromato ion is connected to three manganese ions, resulting in layers which are parallel to the ab plane. The layers are constructed from {Mn 3 Cr 3 } meshes, each metal atom being shared between three other meshes. The structure is expanded into the third direction by connecting the inorganic layers through 4,4′-bipy spacers. The thermal decomposition of the two compounds has been investigated.