Dioctadecyldimethylammonium chloride

If D B, D J Tildesley, MRS Pinches, J B Kingdon, T Madden and A Clark 1995. Molecular Dynamics Simulations of Dioctadecyldimethylammonium Chloride Monolayers. Langmuir 11 237-246. 

An extraordinary way of stabilizing RUO2-coated CdS colloids for H2 generation was chosen by Fendler and co-workers The colloidal particles were generated in situ in surfactant vesicles of dioctadecyldimethylammonium chloride and dihexa-decyl phosphate. Thiophenol as a membrane permeable electron donor acted as a sacrificial additive. Later, a surface active re-usable electron donor (n-C,gH3,)2N — (CHj)—CH2—CHj—SH, Br was incorporated into the vesicles. Its R—SS—R oxidation product could be chemically reduced by NaBH to regenerate the active electron donor. The H2 yields in these systems were only 0.5 %. However, yields up to 10% were later reported for a system in which CdS was incorporated into a polymerizable styrene moiety, (n-C,jH3jC02(CH2)2) N (CH3) (CH2CgH4CH=CH2>, CP, and benzyl alcohol was used as the electron donor. 

Hexadecylpyridinium chloride (cetylpyridinium chloride) Hexadecylpyridinium bromide (cetylpyridinium bromide) Dioctadecyldimethylammonium chloride... 

NaA0T-n-heptane-H20 reversed micelles Single-compartment, 800-to 1000-A-diameter dihexadecylphosphate (DHP) surfactant vesicles Single-compartment dioctadecyldimethylammonium chloride (DODAC) (6) vesicles Thiophenolate-ion-capped, size-quantized CdS generated in situ in reversed micelles CdS particles prepared in situ in vesicles from Cd2+ by controlled exposure to h2s CdS particles generated in situ in DODAC vesicles by several methods... 

Langmuir-Blodgett (LB) films prepared from cadmium arachidate LB films formed from dioctadecyldimethylammonium chloride (6) Size-quantized CdS particles formed in situ between the polar headgroups of the LB film Hexamethylphosphate-stabilized, size-quantized CdS... 

Single-bilayer dioctadecyldimethylammonium chloride (DODAC) (6) vesicles Sonication of surfactant-stabilized magnetite with DODAC Vesicle-incorporated magnetite influenced the outcome of benzophenone photolysis 789... 

DODAC dioctadecyldimethylammonium chloride 0% o.p. a racemic product 100% o.p. a pure enantiomer... 

Interactions between hydrophilic monolayers have deserved considerable attention due to their importance in understanding phenomena that govern stability and fusion of biological membranes. For instance, Claesson et al. [95] have characterised the forces acting between dihexadecylphosphate (DHP) monolayers supported by dioctadecyldimethylammonium chloride hydro-phobised mica and compared the stability of DHP layers on hydrophobic mica surfaces. The authors demonstrated that less than 2% of all DHP molecules deposited onto hydrophobised mica surfaces are charged at pH 5-6. The... 

Vesicles of dioctadecyldimethylammonium chloride (DODAC) are relatively resistant to permeation of organic anions at 25 °C, at imposed exolendo pH gradients of 3 units. Thiophenolate anions, for example, can not be oxidized by o-iodosobenzoate if both reagents are encapsulated in DODAC vesicles (Figure 4.20). Reaction occurs immediately after addition of some ethanol. 

M. Sakaguchi, P. Baglioni, and L. Kevan, Photoreduction of alkylmethylviologens with a-tocopherol in dioctadecyldimethylammonium chloride vesicles, J. Phys. Chem. 96, 2772-2776... 

Didodecyldimethylammonium chloride (hydroxide) Dioctadecyldimethylammonium chloride Base dissociation constant in a micelle based on concentration as a mole ratio... 

Most work has been done with monoalkyl quaternaries, and the conclusions extended to the dialkyl cationic surfactants. This process is incorrect since the monoalkyl derivatives are much more water soluble than the corresponding dialkyl derivatives and they behave differently. Only a few studies have been carried out on DHTDMAC. They are discussed by Crutzen [102], A very different approach was that of Kunieda and Shinoda [88] and Laughlin and co-workers [89,103,104] who studied the phase diagram of dioctadecyldimethylammonium chloride as a model for DHTDMAC deposition. 

The reaction of OH with 5,5 -dithiobis(2-nitrobenzoic acid) is effectively catalyzed by vesicles of dioctadecyldimethylammonium chloride, as well as by micelles... 

Dioctadecyldimethylammonium chloride (DODAC) is a popular synthetic amphiphile that forms vesicles. The quenching efficiency of pyrene derivatives by several quenchers has been studied [98,105]. When iodide is the quencher for the emission of 1-pyrenesulfonate, the k A g(eff) ratios were respectively 0.016 and 0.023 at 20°C and 50°C. These values were smaller than observed for CTAC, suggesting that iodide was efficiently bound to the vesicle. It is known that water penetrates deep into the bilayer [106] and thus, I" may be located in these small water regions. It is also worth noting that an increase to a temperature above the transition temperature (33-37°C) [107] did not change... 

Positively charged vesicles prepared from dioctadecyldimethylammonium chloride (DODAC) [Ci5H3iC02(CH2)2N+(CH3)(CH2C6H4CH = CH2Cr [Fig. 5(b)], as well as from its polymerized counterpart, were found to be better media for CdS-mediated water photoreduction than those prepared from DHP [Fig. 5(c)] [11,12]. Unfortunately, the quantum efficiency of the hydrogen formation was lower than 0.5% and the accumulated oxidized electron donor diphenyl disulfide PhSSPh led rapidly to the ultimate destruction of the vesicles. 

E. Abuin, E. Lissi, D. Aravena, A. Zanocco, M. Macuer, A fluorescence probe study of the effect of size on the properties of dioctadecyldimethylammonium chloride vesicles, J. Colloid Interface Sci., 1988, 122, 201-208. 

J. H. Fendler, W. L. Hinze, Reactivity control in micelles and surfactant vesicles - kinetics and mechanism of base-catalyzed-hydrolysis of 5,5 -dithiobis(2-nitrobenzoic acid) in water, hexadecyltrimethylammonium bromide micelles, and dioctadecyldimethylammonium chloride surfactant vesicles, J. Am. Chem. Soc, 1981, 103, 5439-5447. 

SFG is also widely used to determine the conformation of surfactant monolayers on solid and liquid surfaces [20, 82-84, 98, 99, 108-112, 120, 122]. Figure 8 shows the SFG spectra of a loosely packed monolayer of a cationic surfactant, dioctadecyldimethylammonium chloride (DOAC, (CH3(CH2)i7)2N+(CH3)2C1-), on the fused quartz surface (density 2.8 chains/nm ) in air with polarization combination of (a) ssp (b) sps and (c) ppp [82-84]. In addition to the SFG peaks at 2875, 2955, and 2940 cm , which can be attributed to the terminal GH3 group in a long hydrocarbon chain, the peaks at 2850 and 2920 cm , which can be attributed respectively to the symmetric and asymmetric stretches of the GH2 groups in the alkyl chain, can be observed clearly in comparison with... 

Surfactants have recently been used as models for membranes. Didodecyl-dimethylammonium bromide aggregates extensively in aqueous solutions into stable bilayer structures which further form vesicles and lamellae. Single compartment bilayer dioctadecyldimethylammonium chloride vesicles entrap and retain a number of substrates. Similar aggregation occurs with anionic amphiphiles with two normal alkyl groups as the hydrophobic residue. The hydrolysis of esters catalysed by a hydrophobic imidazole derivative occurs faster (up to 20-fold) in the intravesicle compared with the intervesicle reaction with didodecyldimethylammonium bromide. ... 

X-ray data of dioctadecyldimethylammonium chloride (DODMAC) show a typical structure of dialkylammonium salts [4]. Thermal analysis of dry DODMAC crystals reveals a reversible solid crystalline-solid crystalline phase transition at 325 K i.e., two equilibrium polymorphic forms exist. Melting at —420 K is irreversible and is accompanied by chemical decomposition. 

To produce equilibrium phase data, several cells were loaded, sealed only at the filled end, and stored at room temperature within a 90% RH chamber (prepared from a saturated zinc sulfate solution in equihbrium with crystals and water vapor). After 2 weeks, initiation and DIT studies using these cells displayed none of the above-described behavior. Instead, swelling to form liquid crystal phases occurred at and above the Krafft eutectic temperature. Similar procedures were followed and similar observations made during the dioctadecyldimethylammonium chloride (DOD-MAC)-water DIT study [39]. The difference, in the case of DODMAC, was that much longer equilibration times were required to achieve equilibration (4 months). 

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