Compounds of WVI with 1(+)-sorbitol: Study of formation and interconversion equilibria

Summary The polarimetric study of the W^VI-sorbitol system shows the formation of three stable complexes. The species stable at higher pH is monomeric (WO(OH)(C₆H₁₂O₆)₂]^–), while the other two are dinuclear complexes of different stoichiometries (W₂O₃(OH)₄(C₆H₁₀O₆)]^–2 and W₃O₃(OH)(C₆H₁₁O₆)₂]^–). The interconversion equilibria have been established and the formation constants determined. The behaviour of sorbitol is like that displayed by other polyhydroxylic ligands having one or two carboxylic groups. The substitution of a carboxylic group for an alcoholic one seems only to result in lower stability constants for the complexes formed.