The Crystal Structure of Telluric Acid, Te(OH)6 (mon).

The crystal structure of ditellurium pentoxide, Te2O5

“…The Te-O bond distances in the Te(VI) octahedron range from 1.848 .~ to 1.972 A (Table 6) with a mean value of 1.919 (2)/~,. This value compares quite well with the average Te-O distance of 1.916 (3)/~, found in Te(OH)6 (Lindqvist, 1970). Since there is no significant difference between any of the six crystallographically independent Te-O bond lengths in Te(OH)6, the value 1-919 (3)/k may be regarded as being the length of an unaffected Te-O octahedral a-re bond.…”

“…Fig. 1 and Table 6) found, for example, in Te(OH)6 (Lindqvist, 1970), while the coordination of Te(IV) is irregular fourfold (cf. Fig.…”

The molecular structure of the hexamolybdotellurate ion in the crystal complex with telluric acid (NH4)6[TeMo6O24].Te(OH)6.7H2O

“…The telluric acid molecule is a nearly regular octahedron with an average Te-OH distance of 1.91 A and an average OH-OH distance of 2.70.2t. A recent crystal structure analysis of the monoclinic form of telluric acid Te(OH)6 using X-rays (Lindqvist, 1970) and neutrons (Lindqvist & Lehmann, 1973) has also shown that the molecule is a regular octahedron with a Te-O bond length of 1.909+0.001/k. The minor deviations of the individual bond lengths and bond angles from the averages for both the molybdotellurate and telluric acid groups are not greater than would be expected from the steric influences of crystal packing, and especially the effect of the hydrogen bonds in which the hydroxyl groups are involved.…”

Neutron structural refinement of cubic orthotelluric acid

“…Gossner & Kraus (1934) were the first to assign to the latter modification space group No. 14 (International Tables for X-ray Crystallography, 1952), and recently accurate investigations by singlecrystal X-ray (Lindqvist, 1970) and neutron diffraction methods (Lindqvist & Lehmann, 1973) have shown that monoclinic orthotelluric acid indeed crystallizes in the space group P2~/n. Further structural studies of the monoclinic form are, therefore, unnecessary.…”