One-Size Adjustable-Gap Cluster Anions: Systematic Approach to Multinary, Water-Soluble Chalcogenidometalate Compounds

Reactions of defined mixtures of ternary salts [K4(H2O)4][SnSe4] and [K4(H2O)0.5][SnTe4] with transition-metal ions M = Zn2+ or Mn2+ provide an easy approach to penternary salts of quaternary cluster anions [M4Sn4Se17−xTex]10−, with x corresponding to the Se/Te ratio of the reactant mixture. In this way, it is possible to generate both protic solutions and single crystals with finely adjustable electronic excitation energies Eg; the fact that the Eg values cover the whole visible part of the electromagnetic spectrum as a function of the parameter x spotlights these cluster compounds with respect to diverse photocatalytic applications.