Germanate

In the naming of inorganic compounds it is a suffix that indicates a polyatomic anion with a central germanium atom,[1] for example potassium hexafluorogermanate, K2GeF6.

[2] Neutral solutions of germanium dioxide contain Ge(OH)4, but at high pH germanate ions such as GeO(OH)−3, GeO2(OH)2−2 are present.

[10][11] A common method of preparation is hydrothermal synthesis using an organic amine as a template (structure determining agent).

[12] The frameworks are negatively charged due to extra oxide ions which leads to higher coordination numbers for germanium of 5 and 6.

In addition to the ability of germanium to exhibit 4, 5 or 6 coordination, the greater length of the Ge–O bond in the {GeO4} tetrahedral unit compared to Si–O in {SiO4} and the narrower Ge–O–Ge angle (130°–140°) between corner shared tetrahedra allow for unusual framework structures.