Quaternary ammonium periodates

Quaternary ammonium periodates, prepared either from periodic acid and the quaternary ammonium hydroxide [21, 22] or by metathesis from sodium periodate and a quaternary ammonium salt [e.g. 23-25], have been used for a range of oxidations at stoichiometric levels in two-phase systems [21-33], The tetra-n-butyl-ammonium and hexadecyltrimethylammonium salts are both highly soluble in organic solvents (considerably less so in water), whereas benzyltriethylammonium periodate has a lower solubility and stability than either salt. 

Although there are other more cost effective and efficient procedures, the periodate oxidation of dialkyl sulphides to the sulphoxides has been shown to proceed in high yield [24, 25, 29] thiols are oxidized to disulphides (95-100%) [29]. The potency of the quaternary ammonium periodate for the oxidation of sulphides is improved by the addition of wieso-tetraphenylporphinatoironflll) chloride [TPPFe(III)Cl] [27]. In contrast with the oxidation conducted in the absence of TPPFe(III)Cl [24,25], aryl sulphides are oxidized more rapidly than alkyl sulphides. 

Quaternary ammonium salt polymers are more versatile and have been used in drilling fluids, completion fluids, acidizing treatments, and hydraulic fracturing. No well shut-in period is required. 

The first set of data is for oil production from 22 wells. A quaternary ammonium salt polymer clay stabilizer was utilized in five of the well treatments. Otherwise the 22 well treatment designs were identical. Use of the clay stabilizer in 5 well treatments resulted in a 131% production increase compared to a 156% increase after stimulation of 17 wells without clay stabilizer. Although the initial overall production response of the five clay stabilizer treated wells was less, the overall production decline rate was 4% per year compared to 16%/yr for the treatments which did not include the clay stabilizing polymer. This decline rate was determined for the period 4 to 24 months after well treatment. It is tempting to speculate that the lower initial production response of the five polymer treated wells was due to the formation of an adsorbed polymer layer which reduced formation permeability (particularly of the Wilcox Formation) significantly. 

Cyanuric chloride reacts vigorously and exothermically with DMF after a deceptively long induction period. The 1 1 adduct initially formed decomposes above 60° C with evolution of carbon dioxide and formation of a dimeric unsaturated quaternary ammonium salt. Dimethylformamide is appreciably basic and is not a suitable solvent for acyl halides. 

Alkenes have been oxidized to 1,2-diols (>90%) by catalytic amounts of the ammonium periodate in the presence of osmium, and stoichiometric amounts of the periodate cleave the diols to produce the dicarbonyl derivatives (>80%) [23,30]. The procedure appears, however, to be less effective than with the quaternary ammonium permanganate. 

Dodecyltrimethylammonium chloride is rapidly mineralized in fresh water after an acclimation period, and the rate is faster following the second rather than the first addition of the quaternary ammonium compound. 

Extensive physicochemical studies on RPR 1205 35, a leading product of the series, demonstrated the presence of characteristic multilamellar bilayers, particles of 200 nm, with a surprising periodicity of 80 A (Pitard et al., 1997). Unlike quaternary ammonium lipids, these multilamellar particles are formed in the presence or absence of any helper lipid, such as DOPE (Figure 15.12). 

The reactive chloromethyl moieties incorporated into the monolith served as sites for the introduction of quaternary ammonium functionalities. The pores of the monolith were filled with N,N-dimethyloctylamine, and after a suitable reaction period, the column was washed with methanol and equilibrated with the mobile phase. Unfortunately, only very limited information concerning the nature and extent of modification was presented. 

Studies of adsorption of nonaromatic organic compounds are not as abundant but they are very diverse (and are cited here only to illu.strate and emphasize this diversity). They go back to the interwar period (see, for example, Refs. 571-573, when activated charcoal was being developed for chemical and biological defen.se and its properties were intensely studied [2,3]). More recently, the removal of trihalomethanes [574-579], amines [580,581], acetic acid [582, the pesticide thiram [583], chlorinated organic compounds [584,552,585,586,403, 587-591], alcohols [572,592,593-597], carboxylic and fatty acids [592,483, 598,594,599], N-acetylcysteine [600], amino acids [601], benzo-15-crown-5 ether [602], quaternary ammonium compounds [603], organophosphates and or-ganophosphonates [604] has been studied. Adsorption of surfactants has also been of continued interest [605-614,143,6l5-617. ... 

The alkaline hydrolysis of PET involves treating the polyester with an aqueous solution of sodium hydroxide (4-20 wt%) under pressure at temperatures between 200 and 250 °C for periods of several hours.53,54 Under these conditions the sodium salt of TPA is formed and by acidification TPA is recovered from the solution as a precipitate. It has been observed that the rate of the PET alkaline hydrolysis increases in the presence of quaternary ammonium compounds. Thus, Niu et al.55 have reported on the alkaline degradation of PET fibres with addition of dodecylbenzyldimethylammonium chloride (DBDMAC) into the reaction mixture. A sharp increase in the PET hydrolytic degradation at 80 °C was observed with DBDMAC concentrations in the range 0-1.0 g/1, especially for the least crystalline fibres. The authors concluded that the rate enhancement by quaternary ammonium compounds occurs preferentially on the amorphous regions of the PET fibres. 

Essential oils are active in the inhibition of Gram positive and Gram negative bacteria, yeast, and fungi. These oils usually show weak to moderate activity when compared with chemical biocides such as antibiotics, quaternary ammonium salts, or chlorinated phenols such as triclosan. When the major components are isolated, they usually show improved activity compared to the essential oils. The test methods employed commonly determine inhibition activity via an MIC, but do not usually address the issue of MLC (minimum lethal concentration) or how quickly viable organisms are reduced over a short period of time. In order to determine this, other test methods need to be employed. Differences in... 

A number of developmental methodologies which are of interest in the herbicidal field have been examined for the formation of carbamates and related intermediates. Phosgene and phenol reacted in the presence of triphenylphosphine and a quaternary ammonium salt catalyst at 120-125°C over a total period of 10 hours gave phenyl chloroformate in 89% yield (ref.26). 

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