Imidazolium-based ionic liquids served to selectively methylate terminal chalcogenide ligands of chalcogenidometalate clusters [Sn10S16O4(SMe)4]4−, [Mn4Sn4Se13(SeMe)4]6−, and [Hg6Te10(TeMe)2]6−.

Clusters containing tin atoms show a huge variety of molecular structures, chemical as well as physical properties.

Supertetrahedral clusters have been reported in two generally different types so far:one type possessing an organic ligand shell, no or lowc harges,a nd high solubility,w hile the other cluster type is ligand-free with usually high charges and low or no solubility in common solvents.T he latter is atremendous disadvantage regarding further use of the clusters in solution. However,a so rganic substituents usually broaden the HOMO-LUMO gaps,w hichc annot be overcompensated by the (limited) cluster sizes,afull organic shielding comes along with drawbacks regarding opto-electronic properties.We therefore sought to find aw ay of generating soluble clusters with am inimum number of organic substituents.H ere,w e present the synthesis and full characterization of two salts of [Sn 10 O 4 S 16 (SBu) 4 ] 4À that are high soluble in CH 2 Cl 2 or CH 3 CN, which includes first NMR and mass spectra obtained from solutions of such salts with mostly inorganic supertetrahedral clusters.The optical absorption properties of this new class of compounds indicates nearly unaffected band gaps.T he synthetic approach and the spectroscopic findings were rationalized and explained by means of high-level quantum chemical studies.

A new salt of the alkylated oxo‐thio stannate cluster [Sn10O4S16(SMe)4]4–, (C4C4C1Im)4[Sn10O4S16(SMe)4] (1), was obtained by ionothermal treatment of K4[SnS4]·4H2O. The reaction was carried out in the ionic liquid 1,3‐dibutyl‐2‐methylimidazolium chloride, (C4C4C1Im)Cl, which proved to be non‐innocent against the chalcogenido metallate species in the reaction mixture. In continuation of our first studies on alkylation of very weakly nucleophilic chalcogenido metalate anions, this study served to prove that an N‐bonded alkyl group is selectively released from the imidazolium cation of the ionic liquid, and it served to show that methylation is favored over butylation. The title compound is one of the rare cases, in which the cations of the salt, which stem from the ionic liquid, could be crystallographically determined without problems.