Structure-properties relationship of dimeric surfactants from butyl glucosides

Article abstract of DOI:10.3390/50300608

Carbohydrate containing dimeric surfactants were synthesized starting from D-glucose. Three different spacers were used to link the sugar moieties. The critical micelle concentration (CMC) for these new compounds was determined.

Full text of DOI:10.3390/50300608

608
Molecules 2000, 5
Structure-Properties Relationship of Dimeric Surfactants from
Butyl Glucosides
Mariano J. L. Castro, José Kovensky and Alicia Fernández Cirelli
Centro de Investigaciones en Hidratos de Carbono (CIHIDECAR, CONICET), Departamento de
Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad
Universitaria, Pab. II, 3er. Piso, 1428 Buenos Aires, Argentina
E-mail: mcastro@qo.fcen.uba.ar, jose@qo.fcen.uba.ar, afc@rec.uba.ar
Abstract: Carbohydrate containing dimeric surfactants were synthesized starting from D-
glucose. Three different spacers were used to link the sugar moieties. The critical micelle
concentration (CMC) for these new compounds was determined.
Introduction
Alkyl glucosides are found in nature as glycolipids, and are biosynthesized by micro-organisms us-
ing rhamnose, sophorose and trehalose as carbohydrate sources. Industrially they are prepared from
fatty alcohols and carbohydrates. These compounds have surfactant properties when the alkyl chain
contains at least 4 carbon atoms. Alkyl glucosides are replacing usual non ionic surfactants due to their
biodegradability and to the absence of toxic effects.
Recently, a new class (type) of surfactants, named dimeric [1] or gemini [2] have been prepared.
They have 2 hydrophobic chains, 2 hydrophilic groups, and a spacer (flexible or rigid) keeping away
the two polar groups.
In this communication, we report on the synthesis of dimmer surfactants from butyl α-D-
glucopyranoside, and we analyze their interfacial properties.
Experimental
Gemini surfactants were prepared by condensation between suitable protected butyl α-D-
glucopyranoside and acyl dichlorides [3,4] (Fig. 1). The products were characterized by spectroscopic
/methods (NKr, IR., MS). Molecular formula were confirmed by elemental analysis. Critical micelle
concentrations (CMK) of two compounds was determined by the maximum bubble pressure methods
[5].

609
Molecules 2000, 5
OR'
O
O
X
O
ClCO-X-COCl
RO
RO
O
O
RO
RO
O
O RO
RO
Et3N, tolueno, t.a.
RO
RO
RO
OBu
OBu
OBu
1 R = R' = H
5 R = Bn, X = (CH2)3
6 R = Bn, X = (CH2)2
7 R = Bn, X = C6H4
8 R = H, X = (CH2)3
9 R = H, X = (CH2)2
10 R = H, X = C6H4
H2 (1 atm)
2 R = H, R' = Tr
3 R = Bn, R' = Tr
4 R = Bn, R' = H
Pd/C, MeOH
Figure 1.
Results and Discussion
CMC data showed an important (one order of magnitude) diminution of CMC of dimeric surfac-
tants when compared to their monomeric counterpart.
On the order hand, differences in interfacial properties were observed varying the nature of the
spacer and the position of linking, that can be explained from the conformation adopted by the surfac-
tant molecule (Fig. 2).
Figure 2. Optimized structure of 1,4-bis-[2-O-(n-butyl-a -D-glucopyranosid] succinate calculated by
AM1 method.
Acknowledgements: This work have been performed with financial support of Universidad de Buenos
Aires (UBA) and the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET).
References and Notes
1. Zana, R.; Benrraou, M.; Rueff, R. Langmuir 1991, 7, 1072.
2. Menger, F. M.; Littau, C. A. J. Am. Chem. Soc. 1991, 113, 1451.
3. Castro, M. J. L.; Kovensky, J.; Fernández Cirelli, A. Tetrahedron Lett. 1997, 38, 3995.
4. Castro, M. J. L.; Kovensky, J.; Fernández Cirelli, A. Tetrahedron. 1999, 55, 12711.
5. Möbius, D., Miller R. Drops and Bubbles in Interfacial Research; Elsevier Science: 1998, pp.
279-326.