The oxygen chemistry of pentavalent arsenic and antimony

The oxygen chemistry of pentavalent arsenic and antimony The oxy-compounds of pentavalent arsenic 

The pentoxides of As, Sb, and Bi cannot be prepared, like P2OS, by direct oxidation of the element, for they decompose at high temperatures with loss of oxygen. As20j is prepared by dehydration of its hydrates  

The second of these compounds. H3ASO4. i H2O, is a hydrate of H3ASO4 for it consists of a hydrogen-bonded assembly of tetrahedral AsO(OH)3 molecules and H2O molecules. The third compound, HSAS3O10, consists of infinite chains of octahedral and tetrahedral groups sharing vertices as shown in Fig. 20.lS The H 

There is also tetrahedral coordination of As in cacodylic acid, which form hydrogen-bonded dimers in the crystal like carboxylic acids  

Octahedral coordination of As by 0 in the catechol derivative and in H5AS3O10 has already been mentioned. 

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