Slavi Sevov's group have recently published a paper in the journal Inorganic Chemistry. Sevov's group are one of the very few other groups in the world who study Zintl ions, however their research is mainly focussed on the group 14 Zintl ions, E94– (E = Si, Ge, Sn, Pb). Some examples of Sevov's recent work with group 14 Zintl ions can be found here and here. This latest research concerns the synthesis of [Ge9(Si(SiMe3)3)3]– from Ge94– and Si(SiMe3)3Cl.
Schnepf has previously synthesised [Ge9(Si(SiMe3)3)3]– by reacting GeBr with Li[Si(SiMe3)3], however Sevov has discovered a much simpler and more convenient method. This method involves reacting the K4Ge9 Zintl phase with Si(SiMe3)3Cl in acetonitrile and in the presence of 2,2,2-crypt. This resulted in the formation of [K(2,2,2-crypt)][Ge9(Si(SiMe3)3)3], which contains the [Ge9(Si(SiMe3)3)3]–
cluster anion.
[Ge9(Si(SiMe3)3)3]–
consists of a tricapped trigonal prismatic Ge94– cluster, which is bonded to the three Si(SiMe3)3 groups via its three capping atoms.
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[Ge9(Si(SiMe3)3)3]–.
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The synthesis of [Ge9(Si(SiMe3)3)3]– is exciting because it was thought for a long time that only the mono- and disubstituted [Ge9(ER3)]3– and [Ge9(ER3)2]2–
(E = Ge, Sn; R = Me, Ph) species were accessible. This research suggests that further examples of trisubstituted Ge94– clusters could be easily formed, and also that the so far elusive tetrasubstituted clusters, Ge9R4, might one day be synthesised.
