Si modified Ge10 cluster: the preparation and characterization of single crystal Na4(Ge,Si)9O20

A Si modified Ge₁₀ cluster with structure Na₄(Ge,Si)₉O₂₀ (denoted as HUT‐1) was synthesized by hydrothermal synthesis at 160 °C with a sodium silicate source. The compound was characterized by single crystal, powder X‐ray diffraction and TGA‐DSC analysis. HUT‐1 crystallizes in space group I4₁ (80) with calculated unit cell (a=14.966(5) Å, c=7.343(2) Å, V=1644.8(9) ų), which has the same structure as Na₄Ge₉O₂₀. HUT‐1 has a high Si/Ge ratio with an approximate formula of Na₄Ge_7.68Si_1.32O₂₀. Single crystal X‐ray structure refinements together with results from X‐ray powder diffraction (XRPD) confirm the occupancy of Si at two tetrahedral sites. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)