Preparation and surface‐ active properties of new amphipathic compounds with two phosphate groups and two long‐ chain alkyl groups

New compounds bearing two dihydrogen phosphate groups and two long‐ chain alkyl groups (octyl or decyl) were prepared in good yields by the reaction of 1,ω‐ bis (alkyloxymethyl)‐ oligo (ethylene glycol)s with polyphosphoric acid. Amphipathic di‐ or tetrasodium phosphates were obtained by neutralization of the free acids with sodium hydroxide, and their surface‐ active properties in water were measured. Almost all these di‐ or tetrasodium phosphates showed good water solubility. Their abilities to form micelles and to lower surface tension were fairly good as compared with general monoalkyl phosphates consisting of one longer alkyl chain and one hydrophilic group. The foaming property of aqueous solutions of the tetrasodium salts was different from that of the disodium salts. The former showed very low foaming ability.