N-alkyl Bromides Research Articles

Design of New V Shaped Thermotropic Liquid Crystals containing Heterocyclic

The characterization and design of this study of new liquid crystals with a V shape compounds containing thiazolidine-2,4-dione and 1,3-phenylene as a core unite with mesophase properties were reported. Preparation and characterization of chloroacetic acid, water, and thiourea to produce thiazolidine-2,4-dione [I] in the presence of strong hydrochloric acid. The 4-hydreoxybenzaldehyde and n-alkyl bromide were reacted with potassium hydroxide to create the n-alkoxy benzaldehyde., then the compound [I] reacted with [II]n in presence of piperidine to produce compounds [III]n. Also, converted resorcinol to a corresponding compound [IV] by refluxing pyridine and DMF with two moles of chloracetyl chloride, after that interacted the compounds [III]n and compound [IV] with sodium acetate to form compounds [V]n. FT-IR and 1HNMR spectroscopy were really used to determine the structures of the produced substances. Using polarized optical microscopy, these mesogens' mesomorphic characteristics were studied (POM).The synthesized molecules exhibited enantiotropic liquid crystal phases, the substances [V]1-4 exhibited an only the enantiotropic nematic phase.

Synthesis and characterization of some new thiazolidinone derivatives containing indole ring

Many new heterocyclic compounds including 4-thiazolidinones containing indole with triazole units were described. The new Schiff bases [VII]a, b and [VIII]a,b synthesized by condensation acid hydrazides [II],[VI] with different (aromatic) aldehydes in absolute ethanol. The refluxing equimolar amounts of the Schiff bases ([VII]a,b, [VIII]a,b) with thioglycolic acid in benzene led to get thiazolidin-4-ones derivatives ([IX]a,b and [X]a-d). Finally, the new derivatives [XI]a-c run out via the reacted compound [IX]a with different n-alkyl bromide (methyl bromide, ethyl bromide, and butyl bromide) in alkaline media.

Physicochemical and solution properties of quaternary-ammonium-salt-type amphiphilic gemini ionic liquids with spacers containing oxygen or nitrogen

Quaternary-ammonium-salt-type amphiphilic gemini compounds 2Cn(Spacer) NTf2 were synthesized by the quaternization of a tertiary diamine and an n-alkyl bromide, followed by an ion-exchange reaction with potassium bis(trifluoromethanesulfonyl)imide [(Spacer) = (2-O-2), (2-O-2-O-2), (2-N-2), (2/2-N-2), (2/2)-OH, (5), (6), and n represents the alkyl chain lengths; n = 10, 12, 14 for the 2-O-2 spacer, and n = 12 for all others]. The compounds with melting points below 100 °C were treated as ionic liquids during the subsequent measurements. The melting points of the amphiphilic gemini compounds could be arranged in the following order, based on the spacer present: (2/2)-OH >> 2/2-N-2 > (2-N-2) > (2-O-2) > (5) > (6) > (2-O-2-O-2). The melting points for 2Cn(2-O-2) NTf2 (n = 10, 12), 2C12(2-O-2-O-2) NTf2, and 2C12(2-N-2) NTf2 could be reduced to <0 °C. The amphiphilic gemini ionic liquids exhibited significantly lower conductivities and higher viscosities than the corresponding monomeric ionic liquids. This was attributed to a decrease in the mobility of the cationic molecules caused by the gemini structure, in which the two monomeric compounds are connected by a spacer. Furthermore, the amphiphilic gemini ionic liquids, particularly those containing oxygen in the spacer, exhibited efficient adsorption at the air/water interface.

Novel 2-amino-4-aryl-6-pyridopyrimidines and N-alkyl derivatives: Synthesis, characterization and investigation of anticancer, antibacterial activities and DNA/BSA binding affinities.

A series of new 2-amino-4-aryl-6-pyridopyrimidines, and their N-alkyl bromide derivatives were designed and synthesized by employing methyl substituted azachalcones. These novel compounds were evaluated and compared to the well-known chemotherapeutics in terms of their anti-cancer and anti-microbial functions, and their DNA/protein binding affinities. In order for the cell proliferation, cytotoxicity and microdilution features to be observed, various cancer cell lines (Hep3B, A549, HeLa, C6, HT29, MCF7) were treated with 2-amino-4-aryl-6-pyridopyrimidines (1-9) and their N-alkyl bromide derivatives (2a-c, 3a-c,5a-c,6a-c, 8a-c, 9a-c). Studies on the cells revealed that both pyrimidines and their alkyl derivatives (i) have a high anti-proliferative and anti-microbial activities, (ii) cause cell rounding, cytoplasmic blebs, and anomalous globular structure, and (iii) strongly bound to DNA/BSA macromolecules. Especially the length of the alkyl chain of the N-alkyl bromides has an increasing effect on the antiproliferative, antibacterial and cytotoxic functions, also DNA/protein binding affinity. Those results indicate the novel compounds to be promising antiproliferative agents, and their anti-cancer potential makes them candidates to be used for cancer therapy.

Characterization and Solution Properties of Quaternary-Ammonium-Salt-Type Amphiphilic Gemini Ionic Liquids

Quaternary-ammonium-salt-type amphiphilic gemini compounds (Cm-2-Cn X, where m and n represent the alkyl chain lengths; m = 4, 6, 8, 10; n = 2, 4, 6, 8, 10; m ≥ n; and X indicates the counterion BF4, PF6, OTf, FSA, or NTf2) were synthesized by the quaternization of N,N,N′,N′-tetramethylethylenediamine and n-alkyl bromide and a subsequent ion-exchange reaction with five different counterions. For comparison, the corresponding monomeric compounds (Cn X, n = 2, 4, 6, 8, and 10) were also synthesized. The melting points of the compounds were evaluated using differential scanning calorimetry, and those with melting points lower than 100 °C were treated as ionic liquids during the subsequent measurements. The amphiphilic gemini compounds exhibited the lowest melting points (44–49 °C) when bulky NTf2– was the counterion and the degree of dissymmetry between the two alkyl chains was 0.4 < n/m < 0.75. However, their melting points were not similar to those of the monomeric compounds with NTf2– and n = 4–10 (<29 °C). The gemini ionic liquids exhibited significantly lower conductivities and higher viscosities than those of the corresponding monomeric ionic liquids. This is because of the decrease in the mobility of the cation molecules caused by the gemini structure, in which the two monomeric compounds are connected by a spacer. The gemini ionic liquids also showed higher densities than those of the corresponding monomeric ionic liquids, owing to the dimer of the gemini structure. Further, the gemini ionic liquids were adsorbed readily at the air/water interface and oriented themselves but did not show the critical micelle concentration for the concentration range over which they could be dissolved in water. The amphiphilic monomeric and gemini ionic liquids also tended to form ion pairs in aqueous solutions, as the length of their alkyl chain was relatively short.

Synthesis and biological evaluation of new 2,4,6-trisubstituted pyrimidines and their N-alkyl derivatives

A series of new 2,4,6-trisubstituted pyrimidines and their N-alkyl bromide derivatives were prepared based upon methoxy substituted azachalcones as the starting materials. All newly synthesized compounds were screened for their anti-proliferative, cytotoxic, antibacterial activities and DNA/protein binding affinity. In vitro cell proliferation inhibitory and cell cytotoxic effects of 2,4,6-trisubstituted pyrimidines (1–9) and their N-alkyl bromide derivatives (2a-c, 3a-c,5a-c,6a-c, 8a-c, 9a-c) were obtained with the help of the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) cell proliferation, LDH cytotoxicity detection, and microdilution assays. The antimicrobial activity for these compounds was also evaluated following the European Pharmacopoeia 8.0 protocol. The interactions of these compounds with DNA or bovine serum albumin were investigated by the spectrophotometric titration method. When the cytotoxic analysis and anticancer properties of the compounds were examined, most of the compounds significantly exhibited an anti-proliferative potency on cancer cells (IC50 ∼ 2–10 µg/mL) and caused a cytotoxic effect as low as control drugs, 5-fluorouracil, and cisplatin (∼7–15%). Because the compound-DNA adducts are hyperchromic or hypochromic, they caused variations in their spectra. This situation shows they can be linked to DNA by the groove binding mode at a binding constant range of 2.0 × 104 and 2.4 × 105 M−1. The antimicrobial screening results revealed that our new compounds for some human Gram(+) and Gram(−) pathogen bacteria showed remarkable activity with MIC values between <7.81 and 125 µg/mL. Overall, incorporation of alkyl chain to pyrimidines in the generation of N-alkyl bromides has resulted in showing differences in DNA/protein binding affinity, along with anti-proliferative and cytotoxic activity in favor of new compounds.

Synthesis, characterization, spectroscopy and biological activity of 4-((3-formyl-4-hydroxyphenyl)azo)-1-alkylpyridinium salts

The reaction of 2-hydroxy-5-(pyridine-4-yldiazenyl)benzaldehyde with n-alkyl bromides generated five novel azo pyridinium salts in good to excellent yields. The $$^{1}\hbox {H}$$ and $$^{13}\hbox {C}$$ NMR and UV-Vis absorption spectra indicated several tautomers for the new compounds. The NMR, UV-Vis absorption spectra and quantum chemical calculations show that the azo pyridinium salts have a new resonant structure compared to the corresponding azo precursor. Antibacterial activity was studied by disc diffusion and MIC methods. Diphenylpicrylhydrazyl (DPPH) assay was used to determine the antioxidant properties. The effects of carbon chain length on antimicrobial activity were also investigated. The results showed that existence of alkyl groups is crucial for the antibacterial properties. The new compound with decyl group displayed the best antibacterial activity. SYNOPSIS Five novel azo pyridinium salts were synthesized in high yield. Resonant structures in azo pyridinuim were studied by $$^{1}\hbox {H}$$ NMR and UV-Vis spectra. Antibacterial and antioxidant properties were also investigated.

Synthesis and characterization of new homologous series of unsymmetrical liquid crystalline compounds based on chalcones and 3, 5-disubstituted isoxazoles

Two homologous series of unsymmetrical alkylated chalcones and 3,5-diaryl isoxazoles, consisting of 20 members, with various n-alkyl bromides (n=2−7, 10, 12, 14, 16) have been synthesized and studied for their liquid crystalline property. Simple strategy was employed to achieve the target materials. Flexibility in the synthesized molecules is provided by attaching straight alkoxy chains, where one terminal group is fixed and other terminal group is varied. The synthesized compounds were characterized on the basis of Mass, IR and NMR spectroscopy. The stability and the range of the mesophases increased with the length of the chain on the isoxazoles. The melting point, transition temperatures and enantiotropic liquid crystal morphologies were determined by polarizing optical microscopy (POM) in conjunction with a hot stage and by differential scanning calorimetry (DSC). Two homologous series of unsymmetrical alkylated chalcogens and 3,5-diaryl isoxazoles were synthesized and characterized by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC).

Poly(ionic liquid) prepared by photopolymerization of ionic liquid monomers as quasi-solid-state electrolytes for dye-sensitized solar cells

Vinylimidazolium-typed poly(ionic liquids) (PILs) are prepared by photo-polymerization of ionic liquid monomers. Vinylimidazolium-based ionic liquid monomers with C4 and C8 alkyl tail length were synthesized via quaternization of 1-vinylimidazole with corresponding n-alkyl bromides. Polymerization was conducted at a 3wt.% of photoinitiators in these monomers using illumination of 36W LED light. In the same procedure, preparation of cross-linked PILs was performed in the presence of 15mol% of divinylimidazolium-based cross-linker. These PILs are characterized by using chemical structure, physical characteristics, and electrical conductivity. Electrical conductivity of C4-based PILs is greater than that of C8-based PILs, whereas linear PILs are higher than crosslinked PILs. Crosslinked PILs have higher glass transition and thermal decomposition temperatures as compared linear PILs. PILs consist of the repeating units of anion and cation pair. Its nature has moderate electronic conductivity, which is suitable use in gel-type or quasi-solid-state dye-sensitized solar cells (DSSCs). The linear PILs were incorporated in DSSCs obtaining an efficient quasi-solid-state cell to solve the leakage of liquid electrolyte in a liquid-type DSSC.

Synthesis and Solution Properties of Adamantane Containing Quaternary Ammonium Salt-type Cationic Surfactants: Hydrocarbon–based, Fluorocarbonbased and Bola–type

Quaternary ammonium salt-type cationic surfactants with an adamantyl group (hydrocarbon-type; CnAdAB, fluorocarbon-type; CmFC3AdAB, bola-type; Ad-s-Ad, where n, m and s represent hydrocarbon chain lengths of 8-16, fluorocarbon chain lengths of 4-8, and spacer chain length of 10-12) were synthesized via quaternization of N, N-dimethylaminoadamantane and n-alkyl bromide or 1, n-dibromoalkane. Conductivity and surface tension were measured to characterize the solution properties of the synthesized adamantyl group-containing cationic surfactants. In addition, the effects of hydrocarbon and fluorocarbon chain lengths and spacer chain length between headgroups on the measured properties were evaluated by comparison with those of conventional cationic surfactants. The critical micelle concentration (CMC) of CnAdAB and Ad-s-Ad was 2/5 of that for the corresponding conventional surfactants CnTAB and bola-type surfactants with similar number of carbons in the alkyl or alkylene chain; this was because of the increased hydrophobicity due to the adamantyl group. A linear relationship between the logarithm of CMC and the hydrocarbon chain length for CnAdAB was observed, as well as for CnTAB. The slope of the linear correlation for both surfactants was almost the same, indicating that the adamantyl group does not affect the CMC with variations in the hydrocarbon chain length. Similar to conventional surfactants CnTAB, the hydrocarbon-type CnAdAB is highly efficient in reducing the surface tension of water, despite the large occupied area per molecule resulting from the relatively bulky structure of the adamantane skeleton. On the other hand, the bola-type Ad-s-Ad resulted in increased surface tension compared to CnAdAB, indicating that the curved chain between adamantyl groups leads to poor adsorption and orientation at the air-water interface.

Crystalline structure and phase behavior of N-alkylated polypyrrole comb-like polymers

We report the crystalline structure and phase behavior of a series of comb-like polymers (PPy-Cn), which were prepared via N-alkylation reactions between a pyrrole monomer and n-alkyl bromides (n = 18–26). Analysis by temperature-dependent X-ray diffraction and Fourier transform infrared spectroscopy (FTIR), as well as differential scanning calorimetry reveals that the crystal structure, thermal events and packing mode are affected by PPy backbones, which exhibit stronger rigidity than those of previously reported comb-like polymers. Remarkably, variable-temperature (VT)-FTIR proves the formation of orthorhombic phase at very low temperature, while VT-wide-angle X-ray diffraction only presents the hexagonal phase, illustrating that FTIR is a very sensitive tool for analyzing the micro-packing mode of molecular chains. The enhanced side-chain crystallizable carbon atoms indicate that PPy polymeric backbones play a negative role in the regular packing of nano-crystallites formed by alkyl groups.

Thermochemistry of the pyridinium- and pyrrolidinium-based ionic liquids

We applied DSC for the determination of enthalpies of synthesis reactions of pyridinium- and pyrrolidinium-based ionic liquids (ILs) from pyridine (or N-methyl-pyrrolidine) and n-alkyl bromides (with n = 4, 5, 6, 7, and 8). The combination of reaction enthalpy measurements by DSC with modern high-level first-principles calculations opens valuable indirect thermochemical options to obtain values of enthalpies of the formation and vaporization enthalpies of ILs.

Ionic Liquids: Differential Scanning Calorimetry as a New Indirect Method for Determination of Vaporization Enthalpies

Differential scanning calorimetry (DSC) has been used to measure enthalpies of synthesis reactions of the 1-alkyl-3-methylimidazolium bromide [C(n)mim][Br] ionic liquids from 1-methylimidazole and n-alkyl bromides (with n = 4, 5, 6, 7, and 8). The optimal experimental conditions have been elaborated. Enthalpies of formation of these ionic liquids in the liquid state have been determined using the DSC results according to the Hess Law. The ideal-gas enthalpies of formation of [C(n)mim][Br] were calculated using the methods of quantum chemistry. They were used together with the DSC results to derive indirectly the enthalpies of vaporization of the ionic liquids under study. In order to validate the indirect determination, the experimental vaporization enthalpy of [C(4)mim][Br] was measured by using a quartz crystal microbalance (QCM). The combination of reaction enthalpy measurements by DSC with modern high-level first-principles calculations opens valuable indirect thermochemical options to obtain values of vaporization enthalpies of ionic liquids.

Impact of fluorine substituents on the rates of nucleophilic aliphatic substitution and β-elimination

A measure of the quantitative effect of proximate fluorine substituents on the rates of SN2 and E2 reactions has been obtained through a study mainly of reactions of fluorinated n-alkyl bromides with weak base, strong nucleophile azide ion and strong base/nucleophile methoxide ion in the protic solvent methanol and the aprotic solvent, DMSO. The order of reactivity for SN2 reactions of azide in methanol at 50°C was found to be: n-alkyl-Br>n-alkyl-CHFBr>n-perfluoroalkyl-CH2CH2Br≫n-perfluoroalkyl-CH2Br>n-alkyl-CF2Br. Approximate relative rates of reaction were: 1, 0.20, 0.12, 1×10−4, <7.7×10−5. The order of reactivity for E2 reactions was found to be: n-perfluoroalkyl-CH2CH2Br≫n-alkyl-CF2Br>n-alkyl-CHFBr>n-alkyl-Br. The approximate relative rates for reaction of methoxide in methanol at 50°C were: 1100, 4.4, 1.9, 1.

Poly(ionic liquid) Latexes Prepared by Dispersion Polymerization of Ionic Liquid Monomers

In this contribution, we report the facile preparation of vinylimidazolium-typed poly(ionic liquid) (PIL) latexes and nanoparticles via dispersion polymerization of ionic liquid monomers in aqueous solutions. A homologous series of vinylimidazolium-typed ionic liquid monomers with different alkyl tail length (C8−C18) were synthesized via quaternization of 1-vinylimidazole with corresponding n-alkyl bromides. Dispersion polymerization of these monomers was conducted at a monomer concentration of 50 g/L in aqueous solution at 70 °C without addition of further stabilizers. For ionic liquid monomers with sufficiently long alkyl chains (≥C12), PILs nanoparticles of 20−40 nm in diameter were found, which were self-stabilizing in aqueous media. In the same procedure, preparation of cross-linked PIL nanoparticles was performed in the presence of 10 mol % of divinylimidazolium-based cross-linker. The as-synthesized cross-linked PIL nanoparticles could be transferred into organic solvents, such as polar DMF, and no...

Confined crystallization and phase transition in semi-rigid chitosan containing long chain alkyl groups

We report on the confined crystallization and polymorphism behavior of a series of comb-like polymers (CS(n)Cs), which were prepared via an N-alkylation reaction between chitosan and n-alkyl bromides (n = 14–20). Analysis by temperature-dependent synchrotron X-ray scattering, Fourier transform infrared spectroscopy (FTIR), solid-state nuclear magnetic resonance spectroscopy (NMR) and differential scanning calorimetry (DSC) revealed that the phase transition and crystalline structure were sensitively controlled by the length scale and the confinement state of alkyl groups, which could induce different packing structures and conformational variation behavior. Remarkably, phase transition from orthorhombic-hexagonal to monoclinic structure was observed for these side-chain polymers, demonstrating that the length scales of alkyl groups and the microstructure of polymeric backbones play an important role in the evolution of packing mode of nano-crystallites.

Application of the Compensated Arrhenius Formalism to Dielectric Relaxation

The temperature dependence of the dielectric rate constant, defined as the reciprocal of the dielectric relaxation time, is examined for several groups of organic solvents. Early studies of linear alcohols using a simple Arrhenius equation found that the activation energy was dependent on the chain length of the alcohol. This paper re-examines the earlier data using a compensated Arrhenius formalism that assumes the presence of a temperature-dependent static dielectric constant in the exponential prefactor. Scaling temperature-dependent rate constants to isothermal rate constants so that the dielectric constant dependence is removed results in calculated energies of activation E(a) in which there is a small increase with chain length. These energies of activation are very similar to those calculated from ionic conductivity data using compensated Arrhenius formalism. This treatment is then extended to dielectic relaxation data for n-alkyl bromides, n-nitriles, and n-acetates. The exponential prefactor is determined by dividing the temperature-dependent rate constants by the Boltzmann term exp(-E(a)/RT). Plotting the prefactors versus the static dielectric constant places the data on a single master curve for each group of solvents.

Comparison of N-alkyl acridine orange dyes as fluorescence probes for the determination of cardiolipin

The phospholipid (PL), cardiolipin (CL), is found almost exclusively in the inner membrane of mitochondria and loss of CL is considered as an important indication of cell apoptosis. Previously, 10- N-nonyl acridine orange (NAO) has been used as a fluorescent probe for the visualization of CL in mitochondrial cell membranes and in solution. In this work for the determination of CL, we have synthesized two new fluorescent probes, n-tetradecyl acridine orange (C14-AO), and n-octadecyl acridine orange (C18-AO) by reacting acridine orange with the corresponding n-alkyl bromide. Using excitation and emission wavelengths at about 500 and 525 nm and varying the percentage of methanol in water as the solvent, no interaction between CL and the fluorescent probes at 75% is noted but a proportional quenching of the fluorescence signal by CL is observed at 50% or less for C14-AO and 60% or less for C18-AO. Binding efficiency of these fluorescent probes to CL is compared using dye concentrations of 5, 10, and 20 μM. C18-AO shows a better sensitivity than C14-AO and NAO, respectively, but is less selective. For C14-AO, the detection limit and limit of quantitation are 0.07 and 0.21 μM, respectively, which are better than those previously reported for NAO. One anionic PL, phosphatidic acid, shows some quenching interference to both the C14 and C18 dyes but only at concentrations above the working range for sample analysis. The CL in mitochondrial membrane samples is determined by standard addition using C14-AO. The level of CL in the outer mitochondrial membrane compared to the inner membrane is significantly increased due to the addition of cadmium chloride into the cells causing cell apoptosis.

New amphiphilic polyacrylamides: Synthesis and characterisation of pseudo-micellar organisation in aqueous media

In order to offer new tools for developing structure–property relationships for intramolecular associative polymers (polysoaps), the synthesis of three families of comb-like amphiphilic cationic polymers with great structure variability is described. These polymers with amphiphilic repeating units are polyacryl or methacrylamides laterally substituted by a group containing a quaternary ammonium site and a hydrophobic alkyl side chain with 10–16 carbon atoms. Two complementary synthesis methods were developed successfully. In the first method, the tertiary amine groups of neutral polymer precursors were quaternised with various n-alkyl bromides. Five polymers were obtained in this way. On the contrary, the second method consisted of synthesizing first amphiphilic cationic acryl or methacrylamide monomers. The 11 monomers thus obtained were then polymerised by conventional free radical polymerisation in solution. The polymers obtained by both methods only differed in their molecular weights, the second method leading to much higher molecular weights (up to 2 × 10 6 g/mol). A preliminary investigation of the properties of a few of these polymers in solution showed interesting amphiphilic behaviour. The variation of the reduced viscosity of hydro-methanolic polymer solutions with polymer concentration revealed a strong intramolecular macromolecular folding. The microdomains corresponding to the intramolecular association of the hydrophobic alkyl side chains were eventually characterised by pyrene fluorescence spectroscopy. The local polarity of the pyrene probe was considerably lowered with respect to that of the surrounding aqueous phase and was dependent upon the macromolecular structure of the amphiphilic cationic polymers.

Adsorption and aggregation properties of amino acid-based N-alkyl cysteine monomeric and [formula omitted]-dialkyl cystine gemini surfactants

An amino acid-based gemini surfactant derived from cystine (2C n Cys, where n represents the hydrocarbon chain lengths of 8, 10, and 12) was synthesized by reacting cystine with n-alkyl bromide, and its adsorption and aggregation properties were characterized by measurements of equilibrium and dynamic surface tension and dynamic light scattering. The properties of 2C n Cys were compared with those of an amino acid-based monomeric surfactant derived from cysteine (C n Cys). For n = 8 and 10, when compared to C n Cys, 2C n Cys exhibited excellent surface activities, such as a lower critical micelle concentration (cmc), greater efficiency in lowering the surface tension of water, and smaller area occupied per molecule. Adsorption rate at air/water interface decreased with an increase in hydrocarbon chain length, chain number, and concentration of respective compounds. Further, the kinetics were discussed using the monomer diffusion coefficient obtained from short and long time scales in dynamic surface tension plots. In addition, the aggregation properties of 2C n Cys for n = 8 and 10 differed from those in the case of n = 12 . In other words, relatively larger micelles with diameters of approximately 7 nm were formed by 2C n Cys for n = 8 and 10 in comparison to those formed by C n Cys (2–3 nm). On the other hand, for a 0.832 mmol dm −3 2C 12Cys solution, the aggregation structure investigated by cryogenic transmission electron microscopy (cryo-TEM) and small-angle neutron scattering (SANS) revealed the coexistence of small unilamellar vesicles and small rods.