Synthesis of the (Sn4Bi4)2− Anion by Mild Oxidation of (Sn2Bi2)2−

Abstract

AbstractReactions involving Zintl ions are typically carried out in N‐based solvents such as liquid ammonia (NH3(l)), ethane‐1,2‐diamine (en), pyridine (py), or acetonitrile (CH3CN). We are currently investigating the application of other solvents as alternatives. Herein, we present the synthesis of the (Sn4Bi4)2− anion, obtained as its [K(crypt‐222)]+ salt (crypt‐222=4,7,13,16,21,24‐hexaoxa‐1,10‐diazabicyclo[8.8.8]hexacosane), from reactions of the binary, pseudo‐tetrahedral Zintl anion (Sn2Bi2)2− in the presence of phosphines as oxidation agents in ortho‐difluorobenzene (o‐DFB). The cluster comprises 38 valence electrons, hence, represents an arachno‐type architecture according to Wade‐Mingos rules. Micro‐X‐ray fluorescence (μ‐XFS) spectroscopy rationalized the elemental composition of the anion, and quantum chemical studies served to compare the stability of possible structural isomers of the global minimum structure.