Alkali metals hydroxides, carbohydrate complexes

Table VT contains a comprehensive list of known alkali metal hydroxide adducts. Complexes prepared by the interaction of carbohydrates or acetates of carbohydrates with alkali metal hydroxide in anhydrous alcoholic...

Complexes of alkali metals and alkaline-earth metals with carbohydrates have been reviewed in this Series,134 and the interaction of alkaline-earth metals with maltose has been described.135 Standard procedures for the preparation of adducts of D-glucose and maltose with the hydroxides of barium, calcium, and strontium have been established. The medium most suitable for the preparation of the adduct was found to be 80% methanol. It is of interest that the composition of the adducts, from D-glucose, maltose, sucrose, and a,a-trehalose was the same, namely, 1 1, in all cases. The value of such complex-forming reactions in the recovery of metals from industrial wastes has been recognized. Metal hydroxide-sugar complexes may also play an important biological role in the transport of metal hydroxides across cell membranes. 

Table VIII gives the composition of a number of complexes formed by the interaction of alkali metal hydroxide with various carbohydrates in...

Complexing of polyhydroxy compounds with alkali-metal hydroxides and acetates in nonaqueous media is a fairly general phenomenon. In addition, several carbohydrates have long been known to form crystalline addition compounds with sodium and calcium salts. Recently, Mills has provided evidence for the existence, in dilute aqueous solutions, of complexes of neutral polyhydroxy compounds with cations of the alkali metals and alkaline-earth metals. When subjected to paper electrophoresis in solutions containing the metal acetates, many compounds migrated toward the cathode (for examples, see Table I). Except for m-inositol. 

The general structure of alkali metal alcoholates of polyhydroxy compounds is probably very similar to those proposed by Martell and Calvin1 for the alkali metal chelates of o-salicylaldehyde (see Figs. 9 and 10). 148 1M>IM Unfortunately, because of the highly amorphous nature of nearly all pf the alcoholates and adducts formed by the interaction of metal hydroxides with carbohydrates, x-ray diffraction studies have failed to furnish information regarding the precise location of the metal in these complexes. 

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