N Dodecyl bromide

The pioneering work on amphiphilic polyelectrolytes goes back to 1951, when Strauss et al. [25] first synthesized amphiphilic polycations by quaternization of poly(2-vinylpyridine) with n-dodecyl bromide. They revealed that the long alkyl side chains attached to partially quaternized poly(vinylpyridine)s tended to aggregate in aqueous solution so that the polymers assumed a compact conformation when the mole fraction of the hydrophobic side chains exceeded a certain critical value. Thus, Strauss et al. became the first to show experimentally the intramolecular micellation of amphiphilic polymers and the existence of a critical content of hydrophobic residues which may be compared to the critical micelle concentration of ordinary surfactants. They called such amphiphilic polyelectrolytes polysoaps [25],... 

N-dodecyl 3-carbamoyl pyridinium bromide (I) was prepared from vacuum-distilled n-dodecyl bromide (K K) and nicotinamide (Kodak) according to a published procedure (15) and identified... 

Method OP Neat n-dodecylphenyltellurium dibromide (0.53 g, 1.0 mmol) is heated at 230-250°C at 3 torr using a Kiigelrohr distillation apparatus. A colourless liquid distills which is identical to n-dodecyl bromide ( H NMR and GLC analysis) [0.25 g, (90%)]. (A red-brown residue seems to be mainly PhTeBr and on standing exposed to the ambient atmosphere solidifies to a grey solid PhTe(0)Br and the starting dibromide by IR and combustion analytical data.)... 

Disulphides, 1078 dialkyl, 496, 498 Dithizone, 955 Di-p-tolyl ketone, 930, 931 Dixon gauze rings, 97 n-Dodecane, 237 n-Dodecyl bromide, 282 n-Dodecyl chloride, 275 n-Dodecyl p-toluenesuiphonate, 825 Doebner reaction, 463, 465, 710, 711, 719... 

Almost three decades ago, Strauss and co-workers 18) carried out classic work on polysoaps (23) comprised of poly-4-vinylpyridine which had been quatemized on up to 38 % of the nitrogens with n-dodecyl bromide those nitrogens that escaped reaction with n-dodecyl bromide were then derivatized with ethyl bromide. Now addition of KBr to an aqueous solution of a polyelectrolyte normally decreases the viscosity. This is not true for the 38 % polysoap (23) where the viscosity increases with... 

The curves fell into two distinct groups. The top two curves characterize an all ethyl bromide derivative (PEB) and a derivative with 6.7 mol % of the pyridine groups substituted with n-dodecyl bromide and most of the remainder substituted with ethyl bromide (6.7% polysoap). These curves indicate highly extended molecular dimensions typical of normal polyelectrolyte behavior. Of the two derivatives, the 6.7% polysoap has a lower intrinsic viscosity but a larger increase of the reduced viscosity with concentration this result shows the intra- and intermolecular effects, respectively, of the hydrophobic attractions between the dodecyl groups. 

Photophysical studies on a conformational transition of PMA induced by cationic surfactants have been reported (7). The stretched PMA chain at pH 8 collapses on addition of cationic surfactants that is, the hydrophobic interactions between the cationic surfactants that are bonded to the PMA chain lead to refolding of the polymer chain, and thus provide a hydrophobic site for fluorescence probes at pH 8. The cationic polyelectrolyte poly(4-vinylpyridine) quatemized with n-dodecyl bromide (8 i0) or hexadecyl bromide (11) are also examples of hydrophobically modified polyelectrolytes. 

Lee and Fu reported that coupling of phenyltrimethoxysilane (7) with alkyl bromides is possible under selected conditions. 1-Phenyldodecane was obtained in 81 % yield by the reaction of 7 with n-dodecyl bromide at room temperature. P(t-Bu)2Me as an effective ligand and BU4NF (2.4 equiv.) as an activator were used [86]. 

Dodecylbetaine. See Lauryl betaine Dodecyl bromide n-Dodecyl bromide. See Lauryl bromide... 

This procedure was utilized for microidentification of the following alkyl halides (the corrected melting points in C, as determined on a Kofler block, are given in parentheses) methyl iodide (205—206), ethyl chloride (188), ethyl bromide (188), -propyl bromide (176), isopropyl bromide (194), allyl bromide (163), n-butyl chloride (169), -butyl bromide (169), isobutyl bromide (158), sec-butyl bromide (176), n-amyl bromide (156), -heptyl bromide (157 — 158), 2-ethylhexyl bromide (134—135), -nonyl bromide (144), n-decyl bromide (145 — 146), n-dodecyl bromide (143), and benzyl chloride (174—175). 

A number of hydrophobically modified water-soluble polymers have been prepared via post-polymerization reaction. For example, Straus [21] has prepared polysoaps by the quarternization of poly(2-vinylpyridine) with n-dodecyl bromide (Eq. 1.3). 

Straus [22-24] has modulated the effects of association by varying the number of soap molecules, while holding the total linear charge density the same. This condition has been achieved by quaternizing poly(4-vinylpyridine) to various extents with highly hydrophobic n-dodecyl bromide and completing the process with the less hydrophobic ethyl bromide to form hydrophobic polyelectrolytes (1). 

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