A Borogermanate with Three‐Dimensional Open‐Framework Layers

A layered borogermanate with three-dimensional microporosity within the layers, K 4 [B 8 Ge 2 O 17 (OH) 2 ] (monoclinic, space group: C2/c; a=12.095(2), b= 6.7979(14), c=19.944(4) A; β=93.04(3)°; V=1637.6(6) A 3 ; Z=4), has been synthesized in a flux of potassium borate. Because of its three-dimensional pore structure and thermal stability, the compound has the potential to eventually form nanocomposites with polymers and to be processed into thin microporous films.