Complex Formation and Inclusion Compounds

One of the striking properties of the Schardinger dextrins is their ability to form complexes with a variety of organic and inorganic compounds. Many of the complexes, especially with iodine and organic solvents, are relatively insoluble crystalline materials. 

The insoluble complexes or inclusion compounds have considerable utility in that they are effectively used in the separation, purification, and identification of the individual dextrins. French and coworkers measured the solubilities of the a.-, /3-, and y-dextrins in the presence of excess organic liquids. A few representative precipitants are listed in Table III. Two rather striking facts emerge from experiments of this sort. In the first place, it is surprising to find that any water-soluble carbohydrate would form such insoluble complexes with unreactive hydrocarbons, halo-genated hydrocarbons, or the like. In some cases the solubility of the dextrin is reduced to less than 1 % of its water solubility. Secondly, it is rather remarkable that the different dextrins are precipitated with widely dif- 

It is not intended that the detailed formulas in Table V should be taken seriously, but rather as an illustration of the state of confusion that at- 

Halogen Addition Products of the Schardinger Dextrine According to Pringsheim  

Dextrin Compound Total halogen, per cent A tomic halogen, per cent, found 

---