Discussion The diglycine hydrochloric, hydrobromic and hydriodic acid compounds are colorless crystals, stable in the dry condition. They yield the free halogen acids on dissolving in water. They are very soluble in water but the first two are less soluble than the corresponding monoglycine compounds. Their water solubility increases with rise in atomic weight of the halogen. They are insoluble in alcohol and ether. Attempts to prepare the ...