The first structurally characterised lead(II) antimony compound with a chemical bond between lead and antimony, [Pb4(SbSiiPr3)6] (3), was obtained by the reaction of iPr3SiSb-(SiMe3)2 with PbCl2 in Et2O at 0 °C. The Pb4Sb6 cage structure can be described as a Pb4Sb4 heterocube where two SbSiiPr3 edges are replaced by (SbSiiPr3)2. The average Pb–Sb bond length is 297.7 pm. The heterocubane compounds [PbESi-tBu2Ph]4 (E = P, As) were obtained from the reactions of Pb{N(SiMe3)2}2 with tBu2PhSiEH2.
![Graphical abstract: Synthesis of molecular lead–pnictogen compounds including [Pb4(SbSiiPr3)6], the first structurally characterised compound with a lead–antimony bond](http://hg.y866.cn/compound/lib/scimg/usr/1/B921473A.jpg)
