Synthesis and Structural Characterization of Magnesium-Substituted Polystibides [(LMg)4Sb8 ].

Redox reactions of [(L(1,2) Mg)2 ] and Sb2 R4 (R=Me, Et) yielded the first Mg-substituted realgar-type Sb8 polystibides [(L(1,2) Mg)4 (μ4 ,η(2:2:2:2) -Sb8)] (L(1) =HC[C(Me)N(2,4,6-Me3 C6 H2)]2, L(2) =HC[C(Me)N(2,6-i-Pr2 C6 H3)]2). Compounds [(L(1,2) Mg)2] serve both as reducing agents, initiating the cleavage of the Sb-C bonds, and as stabilizers for the resulting Sb8 polyanion. The polystibides were characterized by NMR and IR spectroscopies, elemental analysis, and X-ray structure analysis. In addition, results from quantum chemical calculations are presented.