Straightforward route to the adamantane clusters [Sn₄Q ₁₀]^4- (Q = S, Se, Te) and use in the assembly of open-framework chalcogenides (Me₄N)₂M[Sn ₄Se₁₀] (M = Mn^II, Fe^II, Co ^II, Zn^II) including the first telluride member (Me ₄N)₂Mn[Ge₄Te...

Title full: Straightforward route to the adamantane clusters [Sn₄Q ₁₀]^4- (Q = S, Se, Te) and use in the assembly of open-framework chalcogenides (Me₄N)₂M[Sn ₄Se₁₀] (M = Mn^II, Fe^II, Co ^II, Zn^II) including the first telluride member (Me ₄N)₂Mn[Ge₄Te₁₀]. The reaction of K₂Sn₂Q₅ (Q = S, Se, Te) with stoichiometric amounts of alkyl-ammonium bromides R₄NBr (R = methyl or ethyl) in ethylenediamine (en) afforded the corresponding salts (R₄N)₄[Sn₄Q₁₀] (Q = S, Se, Te) in high yield. Although the compound K₂Sn₂Te₅ is not known, this reaction is also applicable to solids with a nominal composition "K₂Sn₂Te₅" which in the presence of R₄NBr in en are quantitatively converted to the salts (R ₄N)₄[Sn₄Te₁₀] on a multigram scale. These salts contain the molecular adamantane clusters [Sn₄Q ₁₀]^4- and can serve as soluble precursors in simple metathesis reactions with transition metal salts to synthesize the large family of open-framework compounds (Me₄N)₂M[Sn₄Se ₁₀] (M = Mn²⁺, Fe²⁺, Co²⁺, Zn ²⁺). Full structural characterization of these materials as well as their magnetic and optical properties is reported. Depending on the transition metal in (Me₄N)₂M[Sn₄Se₁₀], the energy band gaps of these compounds lie in the range of 1.27-2.23 eV. (Me ₄N)₂Mn[Ge₄Te₁₀] is the first telluride analogue to be reported in this family. This material is a narrow band gap semiconductor with an optical absorption energy of 0.69 eV. Ab initio electronic band structure calculations validate the semiconductor nature of these chalcogenides and indicate a nearly direct band gap.