Hydroxide polymer main chain, structure

The thorium ion, Th4+, is more resistant to hydrolysis than other 4+ ions but undergoes extensive hydrolysis in aqueous solution at pH higher than 3 the species formed are complex and dependent on the conditions of pH, nature of anions, concentration, etc. In perchlorate solutions the main ions appear to be Th(OH)3 +, Th(OH)2+, Th2(OH) +, Th4(OH) +, while the final product is the hexamer Th6(OH)95 of course, all these species carry additional water.19 Hexameric ions exist also for Nbv and for Ce1 v and Ulv [M604(0H)J12 + ions are found in crystals of the sulfates. The metal atoms are linked by hydroxo or oxo bridges. In crystals of the hydroxide, Th(OH)4, or the compound Th(0H)2Cr04 HzO, chain-like structures have been identified, the repeating unit being Th(OH)2+ in solution, the polymers may have similar form (28-1) or may additionally be cross-linked. 

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