Microporous oxides are inorganic materials with wide applications in separations, ion exchange and catalysis. In such materials, an important determinant of pore size is the number of M (where M = Si, Ge and so on) atoms in the rings delineating the channels. The important faujasite structure exhibits 12-ring structures while those of zeolites, germanates and other materials can be much larger. Recent attention has focused on mesoporous materials with larger pores of nanometre scale; however, with the exception of an inorganic-organic hybrid, these have amorphous pore walls, limiting many applications. Chiral porous oxides are particularly desirable for enantioselective sorption and catalysis. However, they are very rare in microporous and mesoporous materials. Here we describe a mesoporous germanium oxide, SU-M, with gyroidal channels separated by crystalline walls that lie about the G (gyroid) minimal surface as in the mesoporous MCM-48 (ref. 9). It has the largest primitive cell and lowest framework density of any inorganic material and channels that are defined by 30-rings. One of the two gyroidal channel systems of SU-M can be filled with additional oxide, resulting in a mesoporous crystal (SU-MB) with chiral channels.

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Incorporation of boron into templated germanate frameworks has been achieved for the first time. Clusters of GeO4 three‐rings are connected by pairs of BO4 tetrahedra into a two‐dimensional framework structure with nine‐ring channels (see picture; GeO4: light gray; BO4: dark gray). The structure topology is very similar to that of (NH4)4[(GeO2)3(GeO1.5F3)2]⋅0.67 H2O, although very different types and sizes of polyhedra are present in the structures.

Open-framework germanates with extra-large channels are built from two different types of clusters. The two different clusters are connected in such a way to form a pseudo-body-centered cluster aggregate (PBCCA). The different packing of PBCCAs resulted in different 3D open-framework germanates.

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