Contribution to the chemistry of rarer elements—LXII

Synthesis and Characterization of the Periodato Complexes of Thorium(IV) : MITh(H2IO6)(OH)2 · 4 H2O

“…There is a notable feature in the IR spectra of the periodato complexes, that is, the ¿ioH vibrations at ca. 1370 cm" 1 have been observed in all of these complexes; and the large number of peaks appearing at the <5 ioh and <S 0 io vibrations reveals that the arrangement of the six oxygen atoms around iodine may not be symmetrical [12], this confirms that the periodate ex- ists in these complexes predominantly in the form of H 2 IO| . This is consistent with the acid dissociation constant of H 5 I0 6 : K al = 2.1 X10 4 , K a2 = 4.9X10" 9 , K a3 = 2.5 X 10~1 2 , which means that in alkaline solution, only three hydrogen can be dissociated [13].…”