Synthesis of surfactants based on pentaerythritol. II. Anionic gemini surfactants

Abstract

Efficient syntheses of three series of anionic gemini surfactants based on pentaerythritol are described. A series of disulfates was prepared by the double displacement of the two cyclic sulfates in the S4-symmetric compound pentaerythritol spirobicyclic sulfate (1) with linear alkoxides. A second series of disulfates was prepared by reaction of the dialkoxides of di-O-alkylpentaerythritols with ethylene sulfate. The di-O-alkylpentaerythritols can be prepared as previously reported by us or by the acid-catalyzed hydrolysis of the first series of disulfates. A series of disulfonates was prepared by reaction of the dialkoxides of di-O-alkylpentaerythritols with 1,3-propanesultone. This last set of reactions was complicated by the formation of oxetanes, which probably arose from initial reversible displacement on sulfur of the sultone alkoxide by the pentaerythritol alkoxide followed by a second intramolecular displacement of the resulting sulfonate. Changing the order of addition to keep the reaction medium from containing excess base as well as lowering the reaction temperature minimized the amounts of these byproducts. All three series had excellent surfactant properties.

Asymmetric cationic gemini surfactants: an improved synthetic procedure and the micellar and surface properties of a homologous series in the presence of simple salts

“…Gemini, or dimeric surfactants, have two matching head groups connected by a linking chain, the most common being an alkylene chain; [1][2][3][4][5][6][7][8] the hydrophobic tails of the head groups may be the same (symmetric gemini surfactant) or different (asymmetric gemini surfactant). The symmetric members of the cationic gemini surfactants listed in the above references are the most commonly studied in the literature, [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] whereas anionic, [25][26][27][28][29][30][31] zwitterionic, [32][33][34] and nonionic gemini [35][36][37] surfactants are comparatively less studied.…”

The partitioning of primary alcohols into the aggregates of gemini amphiphiles determined from diffusion NMR experiments

“…[21][22][23][24][25] The most commonly studied gemini surfactants are the dicationic gemini amphiphiles of the type N,N 0 -bis (dimethylalkyl)-a,oalkanediammonium dibromides (m-s-m), an example of which is N,N 0 -bis (dimethyldodecyl)-a,o-butanediammonium dibromide (12-4-12). 23,[26][27][28][29][30][31][32] Although dicationic gemini surfactants of the m-s-m type have been well studied in the literature, 21,[33][34][35] anionic, [36][37][38][39][40][41][42][43][44] zwitterionic, [45][46][47] and nonionic gemini [48][49][50][51] surfactants have also been examined. Gemini surfactants are superior to conventional single-headed, single-tailed surfactants in terms of their ability to lower surface and interfacial tension, and aggregate at substantially lower concentrations versus their monomeric counterparts.…”