Oxonium perchlorates

A number of hydrates of perchloric acid, HCICV/zfyO. where n = 1, 2, 2.5, 3, and 3.5. are known. These are commonly referred to as the hydronium or oxonium perchlorates, H O+CIO", because of the analogy between the x-ray patterns of these species and ammonium perchlorate. 

Group 14 (IVA) Perchlorates. Perchlorates containing organic carbon have been reported, as have diazomum perchlorates, oxonium perchlorates, and the perchlorate esters. Extreme caution must be used in working with organic perchlorates many decompose violently when healed, contacted with other reagents, or subjected to mechanical shock. 

Thus, lone proton migration (proton translocation or Grotthuss process) occurs in oxonium perchlorate (cpd or perhaps mss) and potassium hydrogen phosphate (mss). 

Experimental proof supporting the above equiUbrium has been given for oxonium perchlorate in the molten salt species corresponding to both sides of the equiUbrium have been observed. The melting may be described by the reaction ... 

Anhydrous materials oxonium perchlorate, acid phosphates, arsenates, sulphates and selenates... 

Oxonium perchlorate H OCIO is the first solid proton conductor whose conductivity, = 3.4 x 10 cm S has been found to be com-... 

Fig. 11.1. Slructure of the low-temperature phase (black circles oxygen atoms) of oxonium perchlorate (H3OCIO4) A, Raman spectra and B, details of the vCI-O(H) stretching region are given for the crystal (line a), the molten salt (Une b) and the aqueous solutions (line c) (with permission).

The Raman spectra of molten oxonium perchlorate show bands characteristic of HCIO4 and support the former reaction. 

Fig. 11.3. (a) Conductivity plot and (b) rotational diffusion coeflBcient 1/t as a function of the inverse temperature of oxonium perchlorate. The rotational diffusion coeflBcient has been measured by quasi-elastic neutron scattering ... 

---