Crystal phases obtained from aqueous solutions of sodium dodecyl sulfate. The structure of a monoclinic phase of sodium dodecyl sulfate hemihydrate

Crystal phases of dodecyl sulfates obtained from aqueous solutions: structure of the rubidium salt

“…The E map C(112) 1.580(2) computed with the phases of the second set having the Rb(2) 0.5080 (1) S(2) 0.6055 (2) highest figures of merit revealed molecular fragments: o (21) 0.4612 (6) the location of all the non-H atoms was completed by o(22) 0.7451 (8) 0 (23) 0.6748 (7) Fourier recycling, o(24) 0.4917 (8) After isotropic and anisotropic refinement of the c (21) 0.394 (1) C (22) 0.230 (1) heavy atoms by block-diagonal least-squares method, C(23) 0-158 (1) all the H atoms were found from successive AF c(24) -0.022 (1) C (25) -0.091 (1) syntheses: their positional parameters were varied in the C (26) -0-273 (1) C (27) -0.341 (1) last cycles of refinement keeping fixed their isotropic c (28) (7) -0.1153 (2) 3.8 (1) 0.4101 (8) -0.0959 (2) 4.7 (2) 0.1461 (7) -0-0582 (2) 3.6 (1) 0.3986 (7) -0.0465 (2) 3-9 (1) 0.320 (1 structural features may be ascribed to the negative charge equally shared among the three non-ester O atoms, as already observed for the monoclinic and triclinic phases of sodium dodecyl sulfate (SDS) (Coiro, Mazza & Pochetti, 1986;Coiro, Manigrasso, Mazza & Pochetti, 1987). The conformation of both independent hydrocarbon chains is almost completely trans-planar: the largest deviations from planarity in the two chains are shown from the sequences C(12)-C(13)-C(14)-C(15) and C(21)-C(22)-C(23)-C(24) with torsion angles of 175-7 (7) and 174.6 (7) °, respectively.…”

“…With the aim of obtaining models to be successively tested in the study of micellar solutions with different techniques we have undertaken the elucidation of crystalline phases of dodecyl sulfates which can be grown from aqueous solutions at a concentration above the critical micellar concentration (Coiro, Mazza & Pochetti, 1986;Coiro, Manigrasso, Mazza & Pochetti, 1987;Coiro, Mazza & Pochetti, 1987). Furthermore, since the micellar growth is very sensitive to the nature of the counterion (Missel, Mazer, Carey & Benedek, 1982), in order to investigate the effect of the counterion on the molecular aggregation of surfactants we are also examining the crystal packing of the same anionic amphiphile with different cations.…”

“…Views of the crystal packing at the ac and the bc planes are shown in Fig. 2 (Sundell, 1977), the hemihydrate phase (Coiro, Mazza & Pochetti, 1986) and the monohydrate phase (Coiro, Manigrasso, Mazza & Pochetti, 1987). At variance with these Na salts, no water molecule is present in the polar region of RDS crystals which, therefore, are characterized by strong Coulombic interactions without screening of water molecules.…”

Sodium 1,12-Dodecylene Disulfate Hydrate

“…The crystal structures of sodium dodecyl sulfate hydrate with varying water content have been reported by several authors (Sundell, 1977;Coiro, Mazza & Pochetti, 1986;Coiro, Manigrasso, Mazza & Pochetti, 1987). The role of head groups in the structural arrangement can be demonstrated by a comparison of the crystal structures of sodium dodecyl sulfate and sodium dodecylene disulfate.…”

Crystal phases of dodecyl sulfates obtained from aqueous solutions: structure of the hexaaquamagnesium salt

“…In order to obtain models of micellar aggregates formed from sodium dodecyl sulfate (SDS) and to verify them with various techniques in the study of micellar solutions, we are following a strategy successfully applied in the structural elucidation of deoxycholate micelles (Campanelli, Candeloro De Sanctis, Giglio & Petriconi, 1984;Conte, Di Blasi, Giglio, Parretta & Pavel, 1984;Esposito, Zanobi, Giglio, Pavel & Campbell, 1987;Esposito, Giglio, Pavel & Zanobi, 1987;Giglio, Loreti & Pavel, 1988). Therefore, crystal phases of sodium dodecyl sulfate, obtained from aqueous solutions at a concentration above the critical micellar concentration, have been investigated by X-ray crystallography (Coiro, Mazza & Pochetti, 1986Coiro, Manigrasso, Mazza & Pochetti, 1987). Furthermore, since micellization is very sensitive to the properties of the counterion (e.g.…”