In this paper we report the synthesis, structure and optical properties of the first examples of a new family of moleculebased perovskite derived materials, transition metal hexathiocyanatobismuthmates M[Bi(SCN) 6 ]. They are the first example of thiocyanate analogues of the cyanide Prussian blues, and to the best of our knowledge are the first molecular perovskites which incorporate heavy p-block cations. These compounds are vividly coloured, due to the presence of LMCT bands, and the higher optical absorption seen in these compounds suggests that thiocyanate-based frameworks may well be useful for photocatalytic applications. We have also demonstrated that the reversible uptake of water compounds can reversibly incorporate guests into their lattice. The chemical space opened up by these compounds, by substituting on the B site and introducing A site cations, and their unusual optical properties, suggests that thiocyanate perovskites could be an important family of molecular framework materials.