Highly Soluble Supertetrahedra upon Selective Partial Butylation of Chalcogenido Metalate Clusters in Ionic Liquids

Abstract

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.

NMR Coupling Constants Based on the Bethe–Salpeter Equation in the GW Approximation

“…Our formalism already includes scalar-relativistic and spin–orbit effects based on the (one-electron) exact two-component (X2C) Hamiltonian − within analytical derivative theory. , To reduce the associated computational costs, the diagonal local approximation to the unitary decoupling transformation , (DLU) is applied. Consequently, the applicability of our GW -BSE approach is not limited by the all-electron relativistic one-electron Hamiltonian and routine calculations can be performed on widely available inexpensive computer hardware. − The calculated SSCCs are compared to those obtained from standard DFT approaches, using experimental and high-level ab initio reference values.…”

Exploration of metal sulfide syntheses and the dissolution process of antimony sulfide in phosphonium-based ionic liquids

“…Dehnen et al , for example, isolated various thio- and oxothiostannates, selenogermanates and -stannates including cations of the imidazolium-based ILs. 22,23,27–30 Among them, the most prominent compound contains the supersphere anion [Ge 24 Sn 36 Se 132 ]. 24–31,32 But also a new modification of K 2 Sn 2 S 5 was accessible, which obviously does not include the IL used.…”

“…22,23,27–30 Among them, the most prominent compound contains the supersphere anion [Ge 24 Sn 36 Se 132 ]. 24–31,32 But also a new modification of K 2 Sn 2 S 5 was accessible, which obviously does not include the IL used. 33…”

Ionothermal Access to Defined Oligomers of Supertetrahedral Selenido Germanate Clusters

“…Recently, we were able to achieve partial alkylation of the supertetrahedral cluster [Sn 10 O 4 S 20 ] 8– in reactive ionic liquids, yielding highly soluble salts of the general composition (cat) 4 [Sn 10 O 4 S 16 (SBu) 4 ] (cat = imidazolium-based ionic liquid cation). 23 The butyl groups lowered the charge of the clusters (4– instead of 8−) and generated solubility in CH 3 CN and CH 2 Cl 2 , while the optical properties were essentially not affected by the alkyl ligands. However, their attachment to the cluster surface is unfavorable in terms of a limited accessibility of reactive sites.…”

“…One step forward for enhancing solubility is the introduction of ionic liquid counterions, which serves to decrease the lattice energy as long as the charge densities are not too large. Recently, we were able to achieve partial alkylation of the supertetrahedral cluster [Sn 10 O 4 S 20 ] 8– in reactive ionic liquids, yielding highly soluble salts of the general composition (cat) 4 [Sn 10 O 4 S 16 (SBu) 4 ] (cat = imidazolium-based ionic liquid cation) . The butyl groups lowered the charge of the clusters (4– instead of 8−) and generated solubility in CH 3 CN and CH 2 Cl 2 , while the optical properties were essentially not affected by the alkyl ligands.…”