Alkali metals carbohydrate complexes

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. 

COMPLEXES OF ALKALI METALS AND ALKALINE-EARTH METALS WITH CARBOHYDRATES... 

Adducts prepared in aqueous media generally possess one or more molecules of water of hydration per molecule, the number being a function of cation, anion, and the combining ratio of carbohydrate to salt. Available data on complexes of simple carbohydrates indicate that three molecules of water per molecule may be the maximum for adducts of alkali metal salts as many as seven have been reported for those of the alkaline-earth metal salts. Most complexes, however, possess only one or two molecules per molecule. Generally, the higher the combining ratio, the smaller is the number of water molecules that can be accommodated by a molecule of the adduct. 

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...

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

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. 

Rendleman, J. A., Jr., Complexes of Alkali Metals and Alkaline-earth Metals with Carbohydrates, 21, 209-271... 

Rendleman, J. a., Jr., Complexes of Alkali Metals and Alkaline-earth Metals with Carbohydrates, 21, 209 — 271 Reynolds, D. D. See Evans, W. L. Richtmyer, Nelson K., The Altrose Group of Substances, 1, 37 — 76 Richtmyer, Nelson K., The 2-(aldo-Polyhydroxyalkyl)benzimidazoles, 6, 175-203... 

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. 

Ion chromatography can be used for the determination of ionic solutes such as inorganic anions, inorganic cations (including alkali metals, alkaline earth metals, transition metals, and rare earth metals), carboxylic, phosphonic and sulfonic acids, detergents, carbohydrates, low molecular weight organic bases, and ionic metal complexes. 

Singly charged ions encompass radical ions, protonated/deprotonated molecules, products of alkali ion additions, or complex ions with other charge carriers. In the case of singly charged radical ions, the molecular weight of an analyte molecule approximately equals to the m/z value of that ion (one electron affects the measurement by only 0.00055 u). In the case of protonated or deprotonated molecules, the m/z values are expressed as m -I- 1 or m - 1, respectively. Alkali metal adducts are also commonly observed in MS for example, m -l- 23 (sodium adducts) or m -i- 39 (potassium adducts). The alkali ions are mostly contaminants, which are very difficult to remove from sample vials, solvents, or sample plates. However, some analytes such as carbohydrates can only be ionized by association with alkali ions [5,6]. 

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